Isocratic high-performance liquid chromatographic determination of tryptophan in infant formulas.

The application to infant formulas of a method for tryptophan determination by isocratic HPLC with UV detection at 254 nm, after derivatization with phenyl isothiocyanate, was studied. Protein was hydrolysed by barium hydroxide at 120 degrees C for 8 h, followed by derivatization with phenyl isothiocyanate, HPLC and UV detection at 254 nm. The optimum chromatographic conditions (pH, ionic strength of elution solvent and eluent ratio) were established. The analytical parameters (linearity, precision, accuracy of derivatization and limits of detection and quantification) were determined. The values obtained demonstrated that the method is useful for determining the tryptophan content of infan…

Sterol Composition in Infant Formulas and Estimated Intake.

Sterol contents in infant formulas (IFs) from the European market were determined, and their intakes by infants between 0 and 6 months were evaluated. Total animal sterols (mg/100 mL) ranged from 1.71 to 5.46, cholesterol being the main animal sterol (1.46-5.1). In general, cholesterol and desmosterol were lower than the human milk (HM) values indicated by other authors. Total plant sterol (mg/100 mL) ranged from 3.1 to 5.0. β-Sitosterol, the most abundant phytosterol, ranged from 1.82 to 3.01, followed by campesterol (0.72-1.15), stigmasterol (0.27-0.53), and brassicasterol (0.14-0.28). Cholesterol intake (mg/day) ranged from 9 to 51 and plant sterol intake (mg/day) from 19 to 50. The ster…

Simultaneous analysis of lysine, Nɛ-carboxymethyllysine and lysinoalanine from proteins

Protein quality was assayed by simultaneous measurement of lysine (Lys), carboxymethyllysine (CML) and lysinoalanine (LAL). GC-FID analysis of N-tert-butyl dimethylsilyl (tBDMSi) derivatives of these amino acids was undertaken. tBDMSi derivates were separated on a CP-SIL 5CB commercially fused silica capillary column (25 m × 0.25 mm i.d., 0.25 μm film thickness) employing a thermal gradient programmed from 200 to 300 °C. The identity of tBDMSi derivatives of Lys, CML and LAL was established by GC–MS while FID detection was employed for quantification. Analytical parameters such as linearity (lysine 350–4200 μM, LAL 3–81 μM, CML 16–172 μM), precision (1–13% variation coefficients), accuracy …

In vitro colonic fermentation of a plant sterol-enriched beverage in a dynamic-colonic gastrointestinal digester

Abstract The impact of a plant sterol-enriched beverage on the sterol metabolism, organic acid production and microbiota composition was evaluated by means of a dynamic gastrointestinal and colonic fermentation model. After one week of fermentation, an absence of sterol metabolites was reported, in accordance with the lack of microbiota related to their metabolism. Although total organic acid content was lower in the ascending colon (AC) compared to the transversal (TC) and descending colon (DC) (28–57 mmol/L vs. 55-87 and 44–64 mmol/L, respectively), its increments, with respect to the initial value, were higher (2-fold vs. 1.6- and 1.5-fold). Increments of acetate, butyrate and propionate…

High-performance liquid chromatographic determination of furfural compounds in infant formulas during full shelf-life

Abstract In order to evaluate the extent of the Maillard reaction in adapted and follow-up infant formulas (IF), a study was made of the evolution of furfural compound (2-furaldehyde, 5-hydroxymethyl-2-furfuraldehyde, 2-furylmethylketone and 5-methyl-2-furaldehyde) in these products, along with their relation to available lysine during the shelf-life period (two years at 20 and 37 °C). Total and free furfural contents were measured by RP-HPLC and UV detection, heating or not the sample in boiling water to free the furfurals bound to proteins and the furfurals formed from precursors. Only 2-furylmethylketone and 5-hydroxymethyl-2-furfuraldehyde were detected. Adapted and follow-up IF showed …

High-performance liquid chromatographic determination of tocopherols in infant formulas

A method for the simultaneous determination of alpha-tocopherol acetate and alpha-, delta-, and gamma-tocopherols by normal-phase high-performance liquid chromatography (HPLC) with a fluorescent detector in infant formula is proposed. The values obtained in the determination of the analytical parameters: linearity, precision, limit of detection and accuracy (analysis of a standard reference material, SRM 1846), confirm the quality of the method. The proposed method is useful for the determination of alpha-, delta-, and gamma-tocopherols and alpha-tocopherol acetate in infant formulas at a low cost and in a total time of 2 h.

Labeling and nutritional education

Abstract Nutritional food labeling has two components, a nutrient declaration on the back-of-package (usually mandatory) and supplementary simple graphical nutrition information on the front-of-package (commonly voluntary), which are aimed at assisting consumers to be aware of the nutritional value of foods in order to make healthy food choices. This is an important tool for nutritional education that can aid consumers in the fight against diet-related chronic diseases that currently constitute a global public health concern worldwide. In this chapter, the main factors involved in the use and understanding of nutrition labels by consumers, and a detailed explanation of the characteristics o…

Effects of different infant formula components on calcium dialysability

The in vitro methods proposed for estimating calcium bioavailability can be useful in studying the effect of dietetic factors. The aim of our work was to study the possible influence of different infant formula components – calcium, phosphorus, lactose, citric acid, ascorbic acid and proteins – on calcium bioavailability, considering dialysability to be an estimate of bioavailability. The 1981 method of Miller et al. with slight modifications (concerted action no 10 – FLAIR project) was applied to 18 commercial infant formulas of six different types: adapted, follow-up, preterm, hydrolysates, lactose-free and soy-based. Significant positive linear correlations between the amount of calcium …

Antioxidant effect derived from bioaccessible fractions of fruit beverages against H2O2-induced oxidative stress in Caco-2 cells

Abstract This work evaluates the effect of bioaccessible fractions from fruit beverages against oxidative stress (OS) in Caco-2 cells. A fruit beverage (grape + orange + apricot) (with/without milk and/or iron/zinc) was subjected to in vitro gastrointestinal digestion, and bioaccessible fractions were incubated with Caco-2 cell cultures. Following preincubation, OS was induced with 5 mM H 2 O 2 . Intracellular reactive oxygen species (ROS), mitochondrial potential (Δ ψ m ), mitochondrial metabolism (MTT test), intracellular reduced glutathione (GSH) and superoxide dismutase activity (SOD) were measured. The data evidenced viable cultures with increased mitochondrial metabolism and GSH-Rd ac…

Impact of high-pressure processing on the stability and bioaccessibility of bioactive compounds in Clementine mandarin juice and its cytoprotective effect on Caco-2 cells.

Mandarin juice is a rich source of antioxidant bioactive compounds. While the content and profile of bioactives are known, the impact of high-pressure processing (HPP) on their stability and bioaccessibility (BA) is unknown, but may allow obtaining safe, nutritious, and fresh-tasting juices with highly extractable bioactive compounds. The stability and BA of bioactive antioxidant compounds in untreated and HPP-treated (400 MPa/40 °C/1 min) Clementine mandarin juices, and the cytoprotective effect of its bioaccessible fractions (BF) obtained after simulated gastrointestinal digestion against H2O2-induced oxidative stress in differentiated Caco-2 cells were investigated. The BF of HPP-treated…

The impact of galactooligosaccharides on the bioaccessibility of sterols in a plant sterol-enriched beverage: adaptation of the harmonized INFOGEST digestion method.

The effect of the addition of galactooligosaccharides (GOS) on sterol bioaccessibility in three plant sterol (PS)-enriched milk-based fruit beverages (without GOS addition (MfB) and with 2.5 g (MfB-G2) and 5.0 g (MfB-G5) GOS per 250 mL) was evaluated after micellar gastrointestinal digestion. Cholesterol bioaccessibility was very similar among beverages, though a slight significant increase (from 80% to 85%) was observed by the addition of 5.0 g GOS. The addition of GOS did not affect total PS bioaccessibility (≈37%). Based on the results obtained after micellar digestion, it has been demonstrated that these beverages could be a suitable food matrix for simultaneous enrichment with PS and G…

High-performance liquid chromatographic determination of Maillard compounds in store-brand and name-brand ultra-high-temperature-treated cows' milk.

Furosine and furfural products of the Maillard reaction are used as specific indicators of the effect of heating treatments on milk quality. Their contents were measured in representative samples of store- and name-brand ultra-high-temperature-treated milks using RP-HPLC with UV detection. Furosine contents ranged from 40.32 to 50.67 and from 65.48 to 310.58 mg/100 g protein in name- and store-brand milks, respectively. Of the furfurals, only hydroxymethylfurfural was detected. The free hydroxymethylfurfural contents of store-brand milks ranged from 0.22 to 1.70 mg/100 g protein. Total hydroxymethylfurfural contents ranged from 0.29 to 0.41 and from 0.72 to 2.21 mg/100 g protein, for name- …

Effect of simulated gastrointestinal digestion on plant sterols and their oxides in enriched beverages

Abstract This study evaluates the bioaccessibility (percentage of soluble compound available for absorption) of plant sterols (PS) and their oxides (phytosterol oxidation products, POPs) after simulated gastrointestinal digestion in fruit (Fb), milk (M) and fruit-based milk beverages with (FbM a ) or without (FbM b ) tangerine juice. In beverages and their bioaccessible fraction (BF), campesterol, campestanol, stigmasterol, β-sitosterol and sitostanol were detected. Bioaccessibility of total PS ranged between 2.62 and 6.48%, FbM b yielding the highest value, followed by FbM a  > Fb > M. Campesterol/campestanol were the most bioaccessible PS. Only oxides of β-sitosterol were detected in beve…

Static Digestion Models: General Introduction

Several in vitro methods have been developed to simulate the physiological conditions of the human gastrointestinal digestion, the simplest being the static methods. The following chapter clarifies the concepts of bioaccessibility and dialyzability, and describes the conditions (pH, enzymes, agitation, etc.) to be applied in oral, gastric and intestinal phases when assessing a food component (nutrient, bioactive or toxin) or a food product, in a single or multi-phase model. The advantages and disadvantages of the static models vs. dynamic and in vivo models are discussed, and a review of specific conditions applied on nutrients (minerals, vitamins, proteins, fatty acids, etc.) and bioactive…

Evaluation of the Cytotoxicity of Cholesterol Oxides in Human Colon Cancer Caco-2 Cells

The content of cholesterol oxides (COPs) in foods varies between 0.1 and 294.3 mg/g. These oxides are formed by auto-oxidative enzymatic processes promoted by the heat treatment of food and/or to exposition of them to the presence of oxygen and sunlight during storage. Their importance is that they are associated with pathological processes like apoptosis, dyslipidemia and pro-oxidative states, among others. The objective was to evaluate the cytotoxicity, by means MTT assay, of 7-keto cholesterol (7KC), cholestane-triol (Triol), α-epoxy cholesterol (α-epoxy C), β-epoxy cholesterol (β-epoxy C) in differentiated Caco-2 cells at 120μM for 24, 48 and 72h.Triol was the most cytotoxic COP, with a…

High-performance liquid chromatographic determination of furfural compounds in infant formulas

Furfural contents in adapted and follow-up infant formulas were measured by RP-HPLC. The evolution of furfural compound contents during storage (a year at 20 and 37 °C) was studied. 2-Furylmethylketone and 5-methyl-2-furaldehyde were not detectable in analysed samples. The differences in the furfural compounds at point zero between both infant formulas has to be ascribed to the differences in protein and iron contents. An increase in free 5-hydroxymethyl-2-furfuraldehyde (HMF), 2-furaldehyde (F) and HMF+F contents was observed in all samples, although the differences were not statistically significant. The storage temperature affected the total HMF content and the storage time affected the …

Determination of mercury in dry-fish samples by microwave digestion and flow injection analysis system cold vapor atomic absorption spectrometry

Abstract Flow injection analysis system cold vapor atomic absorption spectrometry (FIAS-CV-AAS) preceded by a wet digestion in a microwave oven, as a method for measuring mercury in fish was studied. The digestion process and conditions of the FIAS (carrier concentration: HCl 3% v v ; reducing agent: SnCl2 2% w v : filling and injection times: 8 and 25 min, respectively; and sample volumes) were optimized. The analytical parameters of the proposed method (detection limit = 7.7 ng/g; precision intraassay = 6.7%; interassay = 14.0%) demonstrates its adequacy and are similar to the ones (detection limit = 19.4 ng/g; precision intraassay = 11.2%; interassay = 15.9%) obtained using a conventiona…

Amino acid profile of milk-based infant formulas

The protein content and amino acid profile of three milk-based infant formulas, two of which were powdered (adapted and follow-on) and the third liquid, were determined to check their compliance with the EU directive and to evaluate whether or not they fulfil an infant's nutritional needs. To obtain the amino acid profile proteins were subjected to acid hydrolysis, prior to which the sulfur-containing amino acids were oxidized with performic acid. The amino acids were derivatized with phenylisothiocyanate (PITC) and then determined by ion-pair reverse phase high performance liquid chromatography (HPLC) In the case of tryptophan a basic hydrolysis was applied and there was no need of derivat…

Peptide-metal complexes: obtention and role in increasing bioavailability and decreasing the pro-oxidant effect of minerals.

Bioactive peptides derived from food protein sources have been widely studied in the last years, and scientific researchers have been proving their role in human health, beyond their nutritional value. Several bioactivities have been attributed to these peptides, such as immunomodulatory, antimicrobial, antioxidant, antihypertensive, and opioid. Among them, metal-binding capacity has gained prominence. Mineral chelating peptides have shown potential to be applied in food products so as to decrease mineral deficiencies since peptide-metal complexes could enhance their bioavailability. Furthermore, many studies have been investigating their potential to decrease the Fe pro-oxidant effect by f…

7keto-stigmasterol and 7keto-cholesterol induce differential proteome changes to intestinal epitelial (Caco-2) cells

Abstract Recent studies have expanded the appreciation of the roles of oxysterols triggering inflammatory, immune cytotoxic and apoptotic processes, but have not been considered for proteome analysis. A comparative proteomic study in intestinal epithelial cell cultures incubated (60 μM/24 h) with 7keto-cholesterol or 7keto-stigmasterol was performed. The influence of both compounds was studied following the nLC-TripleTOF analysis. Findings were compared to results for control cultures. In the principal component analysis (PCA) of proteome patterns, two components were extracted accounting for 99.8% of the variance in the protein expression. PCA analysis clearly discriminated between the per…

Stability of fatty acids and tocopherols during cold storage of human milk

The stability of fatty acids and tocopherols from human milk from 8 healthy lactating mothers was determined in fresh milk and after cold storage. Refrigeration at 4 °C for 48 h or freezing at −20 °C for 30 days did not significantly decrease fatty acid contents (mg per 100 g human milk), or concentrations of α-, β-, γ- and δ-tocopherol isomers, compared with fresh milk. Results obtained in the present study showed that cold storage under the usual storage conditions in neonatal units, at home or in milk banks did not have a detrimental effect upon fatty acids and tocopherols contents in human milk. Thus, infants can receive stored human milk without losses in the nutritional value of these…

GFAAS determination of selenium in infant formulas using a microwave digestion method.

A method for determining the selenium content of infant formulas is proposed. It includes wet digestion with nitric acid and hydrogen peroxide in medium pressure teflon bombs in a microwave oven and determination by graphite furnace atomic absorption spectrometry (GFAAS). The absence of interferences is checked. Values obtained for the limit of detection (19.4 ng/g), precision (RSD = 2.2%) and accuracy by analysis of a reference material show that the method is reliable.

Determination of sialic acid and gangliosides in biological samples and dairy products: A review

Gangliosides are sphingolipids containing one or more moieties of sialic acid in their structure. Both gangliosides and sialic acid are bioactive compounds related to animal physiology. Due to their biological relevance, analytical methods adapted to each type of matrix have been developed over time. The present study reviews the main methods applied to the analysis of sialic acid and gangliosides in biological samples and dairy products.

Dialyzability of iron, zinc, and copper of different types of infant formulas marketed in Spain

The bioavailability of trace elements in infant formulas is affected by different physiological and dietetic factors. In vitro methods based on element dialyzability have been proposed to estimate the bioavailability. Infant formulas of the same type but from different manufacturers can differ in the salt used for supplementation and in the contents of other components that can affect mineral bioavailability. The aim of our study is to estimate the dialyzability of iron, zinc, and copper of formulas marketed in Spain, in order to detect possible differences in formulas of the same type coming from different manufacturers. At the same time, the effects of the type of formula, the composition…

Effects of Plant Sterols or β-Cryptoxanthin at Physiological Serum Concentrations on Suicidal Erythrocyte Death.

The eryptotic and hemolytic effects of a phytosterol (PS) mixture (β-sitosterol, campesterol, stigmasterol) or β-cryptoxanthin (β-Cx) at physiological serum concentration and their effect against oxidative stress induced by tert-butylhydroperoxide (tBOOH) (75 and 300 μM) were evaluated. β-Cryptoxanthin produced an increase in eryptotic cells, cell volume, hemolysis, and glutathione depletion (GSH) without ROS overproduction and intracellular Ca2+influx. Co-incubation of both bioactive compounds protected against β-Cx-induced eryptosis. Under tBOOH stress, PS prevented eryptosis, reducing Ca2+influx, ROS overproduction and GSH depletion at 75 μM, and hemolysis at both tBOOH concentrations. β…

Sterol stability in functional fruit beverages enriched with different plant sterol sources

Abstract Two different plant sterol (PS) sources (free PS from tall oil and esterified PS from vegetable oils) were used for manufacturing two types of functional beverages (fruit and milk-based fruit beverages), and their PS and phytosterol oxidation product (POP) contents were determined. Gas chromatography–tandem mass spectrometry (GC–MS/MS) was used for identification and gas chromatography–flame ionization detection (GC–FID) for quantitation purposes. Brassicasterol, campesterol, campestanol, stigmasterol, β-sitosterol and sitostanol were the quantified PS, conforming a profile in order with current legislation. The relative percentages of PS differed according to the enrichment source…

Amino acid contents of infant foods.

The protein quality of three milk-cereal-based infant foods (paps) was evaluated by determining their amino acid contents and calculating the amino acid score. Proteins were subjected to acid hydrolysis, prior to which cysteine and methionine were oxidized with performic acid. Amino acids were determined by reverse-phase high-performance liquid chromatography with fluorescence detection with a prior derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate. Tryptophan was determined by reverse-phase high-performance liquid chromatography with ultraviolet detection after basic hydrolysis. Glutamic acid, proline and leucine were the most abundant amino acids, whereas tryptophan and …

Stability of tocopherols in adapted milk-based infant formulas during storage

Abstract An evaluation is made of the effects of added α -tocopherol ( α -T) or α -tocopherol acetate ( α -TAc) combined with iron lactate or sulfate, storage time (up to 17 months) and storage temperature (22°C and 37°C) on the α -TAc, α -T, γ -tocopherol ( γ -T) and δ -tocopherol ( δ -T) content of infant formulas. Tocopherols were measured by normal phase HPLC and fluorescence detection after direct extraction, which allows the determination of both α -TAc and α -T. The α -TAc content was not affected by temperature or storage time, although the α -, γ - and δ -T contents, which were lower at 37°C than at 22°C, were significantly affected. The type of iron salt added (lactate or sulfate)…

Does the addition of caseinophosphopeptides or milk improve zinc in vitro bioavailability in fruit beverages?

Abstract The influence of caseinophosphopeptides (CPPs) added to fruit beverage versus milk based fruit beverage upon zinc retention, transport, and uptake, as well as the influence of Fe supplementation, were studied using a combined simulated gastrointestinal digestion/Caco-2 cell system. Zinc retention, transport, and uptake of milk based fruit beverage was 4- to 5-fold greater than that of fruit beverages with or without CPPs – no statistically significant differences being observed in relation to the presence or absence of CPPs. Possibly, a slow release of CPPs throughout the digestive tract, as can be expected to take place during the digestion of casein, has a more beneficial effect …

Optimization of the Red Tilapia (Oreochromis spp.) Viscera Hydrolysis for Obtaining Iron-Binding Peptides and Evaluation of In Vitro Iron Bioavailability

Iron deficiencies continue to cause significant health problems in vulnerable populations. A good strategy to combat mineral deficiency includes fortification with iron-binding peptides. This research aims to determine the optimal conditions to hydrolyze red tilapia viscera (RTV) using Alcalase 2.4 L and recovery of iron-binding protein hydrolysate. The result showed that under the optimal hydrolysis condition including pH 10, 60 &deg

Determination of Plasma Lipid Hydroperoxides by an NADPH/NADP + Coupled Enzyme Reaction System. Evaluation of a Method

Summary: Several techniques based on different principles have been proposed to measure lipid hydroperoxides. Enzymatic methods are sensitive and can be quite specific but they are subject to interference by inhibitors and not all are stoichiometric. The present work proposes some modifications of the Heath & Tappel (Anal Biochem 1976; 7:184—91) enzymatic method of determination of lipid hydroperoxides in order to standardize and automate it and to meet the analytical criteria required for a biological assay. The proposed new protocol and the automated assay give acceptable within-run and between-run precisions, with coefficients of variation of 3.34% and 5.80%, respectively, at the usual p…

Identification of Casein Phosphopeptides in β-casein and Commercial Hydrolysed Casein by Mass Spectrometry

Casein phosphopeptides (CPPs) in commercial hydrolysed casein (CE90CPP) and in β-CN (β-CN) after simulated gastrointestinal digestion (gastric stage pepsin, pH =2, 37°C 2h) and intestinal stage (pancreatic-bile extract, pH =5.2, 37°C 2h) were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). In β-CN digest five peptides that contained four to five phosphate groups and the cluster sequence SpSpSpEE (residues 17-21) were identified. All CPPs with one exception β-CN(1-24)4P, had the protein fragment β-CN(1-25)4P, which is one of the main CPPs produced in vivo digestion of casein and the re…

Plant sterols and human gut microbiota relationship: An in vitro colonic fermentation study

Abstract Due to the preventive effect that plant sterols could have in relation to colon cancer and the scarce information available on plant sterols-gut microbiota interaction, we evaluate the sterols influence upon gut microbiota and viceversa. In vitro colonic fermentation using a residue from the in vitro digestion of a plant sterol-enriched beverage were used. Faecal sterols by GC–MS, and gut microbiota using DNA sequencing were determined. A higher plant sterols metabolism and lower for cholesterol in presence of plant sterols was occurred. Neutral plant sterols decreased and its metabolites increased during fermentation times. The global changes in microbial communities were associat…

Addition of milk fat globule membrane as an ingredient of infant formulas for resembling the polar lipids of human milk

Polar lipid (PL) contents in human milk (HM) from two different geographic zones in Spain (central and coastal) were determined. These PLs were also analysed in several infant formulas (IFs), three of which contained milk fat globule membrane (MFGM), an ingredient used to resemble the PL profile of HM. Total PL in HM decreased significantly (p < 0.05) from transitional milk (48.62 mg 100 mL−1) to 6 months (28.66 mg 100 mL−1). In HM, sphingomyelin was the most abundant PL, followed by phosphatidylethanolamine; in IFs the most abundant PL was phosphatidylethanolamine. Only IFs with MFGM (54.79–58.07 mg 100 mL−1) could supply the total and individual PL content present in all lactation periods…

Comparison of spectrophotometric and HPLC methods for determining sialic acid in infant formulas

Abstract Two methods for determining sialic acid in infant formulas – spectrophotometry and HPLC with fluorescence detection – have been optimised and validated, the first one allows to determine total sialic acid while the second allows to differentiate the two main forms of sialic acid (N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc)). A common sample preparation procedure (hydrolysis and purification) for both methods has been proposed. The linearity (from 6 to 150 μg of total sialic acid in the assay for spectrophotometry, and from 12.5 to 250 ng and 1 to 5 ng of Neu5Ac and Neu5Gc, respectively, for HPLC) is adequate. The detection and quantification limits (0.29…

Protective effect of antioxidants contained in milk-based fruit beverages against sterol oxidation products

Abstract Sterol oxidation products (SOPs) have shown cytotoxic effect in human intestinal cells; however, their effect within a food matrix has not been assayed yet. This study evaluated the possible cytotoxic effect of SOPs within bioaccessible fractions (BFs) of two milk-based fruit beverages with (BFA)/without (BFB) plant sterols in differentiated Caco-2 cells and if the BFs counteracted the cytotoxic effect induced by COPs mixture (30 and 60 μM). BFs did not evoke cytotoxic effect in any of the tests carried out and they protected against the loss of intestinal cohesion, mitochondrial depolarization and necrosis induced by COPs mixture. Moreover, BFB sample protected from cell cycle arr…

Cytokines profiles in intestinal epithelial (Caco-2) cells exposed to 7-ketostigmasterol or 7-ketocholesterol

Identification of Novel Phosphopeptides After Simulated Digestion of αs2-casein by Tandem Mass Spectrometry

Casein phosphopeptides (CPPs) are encrypted in αs1-, αs2-and β-casein (CN) and can be released by in vitro, in vivohydrolysis or food processing of dairy foods. Bovine αs2-CN contains two cluster sequences of anionic phosphoseryl and glutamyl residues SpSpSpEE in its structure (residues 8–12 and 56–63), which can modulate mineral bioavailability. In this study αs2-casein (αs2-CN) was subjected to simulated gastrointestinal digestion. CPPs released were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). Six novel αs2-CN derived CPPs, Three of them (αs2-CN(54–87)4P,αs2-CN(24–70)4P and αs2-…

Whole blood selenium content in pregnant women

The selenium content in the blood of pregnant women in the Valencian Community, Spain was determined until the end of gestation in order to assess its evolution and detect possible differences in relation to the values corresponding to non-pregnant women of fertile age. A total of 158 blood samples were obtained from 137 pregnant women. Samples were classified as: (a) first; (b) second; and (c) third trimester. Selenium was determined by a flow injection hydride atomic absorption spectrometric method (Seronorm whole blood was used as a quality control check). The selenium values obtained for the three trimesters followed a Gaussian distribution. The intervals for mean found were: (a) 75.7-8…

Effect of simulated gastrointestinal digestion on sialic acid and gangliosides present in human milk and infant formulas.

The effects of simulated gastrointestinal digestion upon sialic acid and gangliosides in infant and follow-on formulas and human milk, as well as their bioaccessibility, have been evaluated. The gastric stage is the step that causes a greater decrease in sialic acid and ganglioside contents. The intestinal stage only decreases the total and individual contents of gangliosides. After gastrointestinal digestion, neither sialic acid nor gangliosides were found in the nonbioaccessible fraction. The highest bioaccessibility (100 × content in soluble fraction after gastrointestinal digestion/total content) of sialic acid is found in human milk (87%), followed by infant formula (77%) and follow-on…

Application of the 6-aminoquinolyl-N-hydroxysccinimidyl carbamate (AQC) reagent to the RP-HPLC determination of amino acids in infant foods.

The validation of a pre-column derivatization procedure with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) to the determination of the amino acid content by RP-HPLC with fluorescence detection (lambda excitation 250 nm, lambda emission 395 nm) in milk-cereal based infant foods was carried out. The analytical parameters: linearity (0.0025-0.2mM), precision of the method (0.2-3.5% variation coefficients), accuracy (derivatization: 86-106% average recovery and method: 88.3-118.2% average recovery) and the limits of detection (0.016-0.367 microM) and quantification (0.044-1.073 microM) were determined. Glutamic acid, proline and leucine were the most abundant amino acid whereas the lowe…

Amino Acid Contents of Infant Formulas

Abstract The amino acid supply in an infant's first month of life must be sufficient in quantity and quality to fulfil the needs of this period of life. Guidelines, recommendations and minimum and maximum values have been established regarding to amino acid composition of infant formulas. The aim of this study was to determine the amino acid profile of infant formulas of different types marketed in Spain in order to assess the compliance with the recommendations (ESPGAN) and to detect possible differences in the amino acid profiles depending on the protein source. Amino acids were determined by HPLC in ion-pair reversed phase after hydrolysis and derivatization with phenylisothiocyanate. Ne…

Impact of a Plant Sterol- and Galactooligosaccharide-Enriched Beverage on Colonic Metabolism and Gut Microbiota Composition Using an In Vitro Dynamic Model

This document is he Accepted Manuscript version of a Published Work that appeared in final form in Journal of Agricultural and Food Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.jafc.9b04796

Direct determination of calcium, magnesium, sodium, potassium and iron in infant formulas by atomic spectroscopy. Comparison with dry and wet digestions methods

An optimization and comparison of three atomic absorption spectroscopic methods for measuring Ca, Mg, Na, K and Fe contents of infant formulas are carried out. The first method is a direct measure of a sample dispersion in water. The second method involves a previous wet digestion (HNO3 + H2O2) in a microwave oven. And finally a dry mineralization at 450 °C is assayed. In order to measure Ca and Mg lanthanum at 0.4% concentration and in the case of Na and K cesium at 0.1% were added. The analytical parameters of the three methods assayed were determined. Results obtained show that the three studied methods are accurace and reliable and no significant difference among them at a probability l…

In vitro interactions between calcium, zinc, copper and iron in milk- and soy-based infant formulas / Interacciones in vitro entre calcio, cinc, cobre e hierro en formulas de base láctea y de soja para lactantes

Interactions among calcium, zinc, copper and iron in milk- and soy-based infant formulas were as sessed in order to evaluate the influence of supplementation with one trace element on the bioavailability of the others. The criterion used to estimate the bioavailability is the percentage of dialysis, estimated by applying an in vitro method. Infant formulas were supplemented with CaCl2, ZnO, CuCO3 Cu(OH) 22H2O and FeSO4 7H2O at two levels (maximum (+) and minimum (-) allowed by the European Union). A factorial design at two levels with three factors (Zn, Cu and Fe addition) was carried out. The main effects and the second-order interactions of the studied factors on the bioavailability of a…

Selenium content of infant formulas and estimation of the intake of bottle fed infants.

Calcium, magnesium, sodium, potassium and iron content of infant formulas and estimated daily intakes

The calcium, magnesium, sodium, potassium and iron content of a total of 22 different infant formulas marketed in Spain were measured by atomic spectrometry, and the mineral intake of infants fed exclusively with these formulas was estimated. The contents (mg/100kJ) are in the following ranges: Ca, 14-24; Mg, 1.1-2.8; Na, 5.6-9.8; K, 19-35; Fe, 0.02-0.50. These values coincide with those recommended by the Codex and European Society for Paediatric Gastroenterology and Nutrition (ESPGAN), and do not exceed the limits established by the European Union (EU). The mean values and ranges of estimated intakes for each formula type and period of infancy (0-1, 1-2, 2-3, 3-4 and 4-5 months) expressed…

Effect of plant sterol and galactooligosaccharides enriched beverages on oxidative stress and longevity in Caenorhabditis elegans

Abstract This study evaluates the impact of two plant sterol (PS) enriched fruit beverages (0.6 g /100 ml), without (MfB) or with GOS (MfB-G) (1.2 g/100 ml) on the resistance against oxidative stress induced by non-conventional (cholesterol oxidation products (COPs)) and conventional (H2O2) oxidant compounds, as well as their impact on C. elegans longevity. Nematodes fed with both beverages (0.005–0.25%, v/v) showed similar improved oxidative stress resistance against COPs and H2O2. This effect was dependent on daf-16 transcription factor, although GOS showed an additional beneficial effect independent to daf-16. In addition, both beverages extended nematode lifespan, independently of the p…

Environmental cadmium, lead and nickel contamination: possible relationship between soil and vegetable content

The cadmium, lead and nickel content of soils of four agricultural areas exposed to different degrees of environmental pollution and vegetables grown there were measured by Atomic Absorption Spectrophotometry (AAS). In order to ascertain the possible relationship between the heavy metal content of soils (total and extractable) and of vegetables grown in them, the correlation between the two was calculated. The highest correlation values between metal content of soil and vegetables are these corresponding to nickel: the total metal content in soils and leaves-stems are linear (p<0.01). The extractable metal content of soils and leaves-stems are linear (p<0.1). Therefore, soil seems to be the…

Fluorometric determination of chemically available lysine: adaptation, validation and application to different milk products.

A spectrophotometric method based on the reaction between available lysine and ortho-phthaldialdehyde (OPA) was adapted and validated for fluorometric determination of the chemically available lysine contents in milk matrices (UHT and conventional in-bottle sterilized cow milk, milk-based infant formulas and infant formula ingredients). The values of the analytical parameters show its usefulness as a routine method (linearity, r = 0.9992; detection limit, 0.0066 mg/mL assay; accuracy, 99-108%; precision, intra-day 2.1-5.9% and inter-day 3.5 10.2%). No statistically significant differences (p < 0.05) were found between the values obtained with the adapted method and those obtained applying t…

Evaluation of the Bioaccessibility of Antioxidant Bioactive Compounds and Minerals of Four Genotypes of Brassicaceae Microgreens

Microgreens constitute an emerging class of fresh, healthy foods due to their nutritional composition. In this study the content of minerals and antioxidant bioactive compounds, and for the first time bioaccessibility, were evaluated in broccoli (Brassica oleracea L. var. italica Plenck), green curly kale (Brassica oleracea var. sabellica L.), red mustard (Brassica juncea (L.) Czern.) and radish (Raphanus sativus L.) hydroponic microgreens. Macro- (K, Ca, Mg) and oligo-elements (Fe, Zn), ascorbic acid, total soluble polyphenols, total carotenoids, total anthocyanins, total isothiocyanates and total antioxidant capacity (Trolox Equivalent Antioxidant Capacity and Oxygen Radical Absorbance Ca…

CHEMICAL ANALYSIS FOR SPECIFIC COMPONENTS | Micronutrients and Other Minor Meat Components

The chemical analysis of the many micronutrients (minerals and vitamins) and other components such as cholesterol and enzymes in meat and meat products are addressed in this article. The sample preparation and main methods for the determination of these components are reviewed and described as well as their respective major advantages and disadvantages.

Effect of traditional, microwave and industrial cooking on inositol phosphate content in beans, chickpeas and lentils

An high-performance liquid chromatography method for determining inositol phosphate fractions was adapted to legumes. The validity of the method was assessed by estimating the following analytical parameters: linearity (linear response between 125 and 5000 microg inositol hexaphosphate (IP(6))/ml); instrumental precision and method precision (relative standard deviation, %) were 1.9% (IP(6)) for instrumental, and 2.5% (IP(6)) and 8.2% (IP(5)) for method precision. An accuracy was estimated by percentage recovery (72 +/- 3%). The application of this method to raw, conventional, microwave-cooked and ready-to-eat beans, chickpeas and lentils gave IP(6) contents ranging from 0.63 g/100 g dry ma…

Antiproliferative effect of plant sterols at colonic concentrations on Caco-2 cells

Abstract Plant sterols (PS) have been incorporated to foods due to their cholesterol-lowering effect. Because of their low intestinal absorption (0.5–2%), they can reach the colon and exert local actions. The aim of this study was to evaluate the antiproliferative effect of individual (β-sitosterol, campesterol and stigmasterol) and combined PS in colon cancer cells (Caco-2) at human colonic concentrations after simulated gastrointestinal digestion of a PS enriched milk-based fruit beverage. β-Sitosterol, campesterol and stigmasterol induced significant cell viability reduction (13–59% vs control), but only stigmasterol produced an overproduction of reactive oxygen species (92% vs control).…

Sterols in infant formulas: validation of a gas chromatographic method.

AbstractSterols are components present in the fat fraction of infant formulas (IFs). Their characterization is therefore of interest, though there are no official reference methods for their analysis in these matrices.Aim: To validate a gas chromatographic method with flame ionization detection for the determination of animal (cholesterol and desmosterol) and plant sterols (brassicasterol, campesterol, stigmasterol, β-sitosterol and sitostanol) found in IFs.All correlation coefficients obtained for the calibration curves of sterols studied were >0.99. Limits of detection (<1 μg/100 mL) and quantification (<4 μg/100 mL) are suitable for sterols determination in IFs. The within-assay precisio…

Methylmercury and inorganic mercury determination in fish by cold vapour generation atomic absorption spectrometry

Abstract Given that organic mercury is more dangerous than the inorganic form and that it is converted into methylmercury by biological methylation, we have studied and optimized a simple method for measuring both organic and inorganic mercury contents in fish, using a spectroscopic vapour generation technique, with a sequential reduction of the digested sample with stannous chloride and sodium tetrahydroborate. Prior to applying the method the sample was subjected to alkaline wet digestion. Due to the matrix interferences calibration curves with matrix addition were needed for mercury determinations. The analytical parameters of the method were: linearity from 10 to 200 ng of Hg in the red…

Direct determination of lead in human milk by electrothermal atomic absorption spectrometry

Abstract Infants are particularly sensitive to the toxic effects of lead. Since milk is their only or main food it is important to know the contribution of milk to lead intake. The purpose of this study was to develop a direct method for determining the lead content of human milk by electrothermal atomic absorption spectrometry when a deuterium lamp is the only background correction available. The optimum conditions for lead determination in breast milk: sample dilution in Triton ×-100, modifier (75 μg of palladium) and nitric acid contents (2%) and the graphite furnace program (mineralization: 1100°C; atomization: 2300°C) were selected. The analytical parameters are: linearity (20–300 ng m…

Milk versus caseinophosphopeptides added to fruit beverage: Resistance and release from simulated gastrointestinal digestion

The influence of simulated gastrointestinal digestion on caseinophosphopeptides (CPPs) formation in milk-based fruit beverage was evaluated, together with resistance of a pool of CPPs added to fruit beverage. In milk-based fruit beverage, four CPPs were identified that can be justified by their presence in raw milk or due to processing. When it was subjected to simulated gastrointestinal digestion, 10 CPPs were identified, and only 1 presented the cluster (SpSpSpEE) (3 phosphoseryl group followed by 2 glutamic acid residues), which corresponded to αs2-CN(1-19)4P. CPPs added to fruit beverage are resistant to simulated gastrointestinal digestion, and 16 CPPs were identified originating from …

Development of Functional Beverages: The Case of Plant Sterol-Enriched Milk-Based Fruit Beverages

Abstract Beverages are by far the most active functional food category, since they are excellent means for delivering nutrients and bioactive compounds such as plant sterols (PS). These phytochemicals are used as functional food ingredients due to their well-known cholesterol-lowering activity. The PS-enriched milk-based fruit beverages seem appropriate for complying with health recommendations (restrictions of saturated fatty acids, cholesterol, and energy value), as good sources of other bioactive compounds (polyphenols, carotenoids, and vitamins), and as a good option for obtaining the recommended daily amount of PS in subjects with moderate hypercholesterolemia. This chapter focuses on …

Antiproliferative Effect of Bioaccessible Fractions of Four Brassicaceae Microgreens on Human Colon Cancer Cells Linked to Their Phytochemical Composition

The antiproliferative effect of the bioaccessible fractions (BFs) of four hydroponic Brassicaceae microgreens (broccoli, kale, mustard and radish) was evaluated on colon cancer Caco-2 cells vs. normal colon CCD18-Co cells after 24 h treatment with BFs diluted 1:10 v/v in cell culture medium. Their bioactivity was compared with the digestion blank, while the colon cancer chemotherapeutic drug 5-fluorouracil was used as a positive control. Cell viability (mitochondrial enzyme activity assay (MTT test) and Trypan blue test) and mechanisms related to antiproliferative activity (cell cycle, apoptosis/necrosis, mitochondrial membrane potential, reactive oxygen species (ROS) production, Ca2+ and g…

Effect of processing and food matrix on calcium and phosphorous bioavailability from milk-based fruit beverages in Caco-2 cells

9 páginas, 4 figuras, 4 tablas.-- et al.

Selenium, Copper, and Zinc Indices of Nutritional Status : Influence of Sex and Season on Reference Values

The objective was to estimate the possible influence of season or season and sex on the selenium, glutathione peroxidase (GSH-Px), copper, zinc, and superoxide dismutase (SOD) values in plasma with a view to establishing reference values. For this purpose, 55 healthy volunteers (36 women and 19 men) were selected and their whole-blood samples were collected four times a year at the beginning of each season. In the population as a whole, no statistically significant seasonal differences were detected in copper, selenium, and GSH-Px values in plasma, whereas zinc and SOD values in plasma depended on the season. In general, the variability was higher among the women. In view of the differences…

Mathematic predictive models for calculating copper, iron and zinc dialysability in infant formulas

Differences in the dialysability of a mineral element from infant formulas of the same type were detected in a previous study. As these may be due to the effects that different levels of the components of the formulas could have on dialysability, we attempted to establish mathematical models to predict the dialysability of Cu, Fe and Zn from infant formulas according to their ascorbic, citric, or selected amino acid contents. A simple linear regression was applied between the ascorbic acid, citric acid and amino acid contents and the Cu, Fe and Zn dialysability of 18 powdered infant formulas of different types. Significant correlations (P<0.05) were obtained between the dialysability of Fe …

Evaluation of Sialic Acid in Infant Feeding: Contents and Bioavailability

Sialic acid (Sia) contents and bioaccessibility (BA) in human milk (HM) and infant formulas (IFs) were determined, and Sia intakes by infants between 0 and 6 months of age were evaluated. Total Sia contents in HM decreased during lactation from 136.14 to 24.47 mg/100 mL. The total Sia contents in IFs (13.15-25.78 mg/100 mL) were lower than in HM and were not related to the addition of ingredients acting as sources of Sia in their formulation. The Sia intakes derived from IF consumption were lower than in HM, and only one IF reached the intakes provided by HM from the age of 2 months. Despite the lower total Sia content in IFs, the BA of Sia in IFs (88.08-92.96%) was significantly greater th…

Effect of proteins, phytates, ascorbic acid and citric acid on dialysability of calcium, iron, zinc and copper in soy-based infant formulas.

The possible effect of ascorbic acid, citric acid, proteins and phytate on dialysability of Ca, Fe, Zn and Cu in soy-based infant formulas is studied, taking dialysability as a measure of the amount of element available for absorption. Different dialysis percentages for similar element contents in different formulas are found. A regression analysis was applied between Ca, Zn, Cu and Fe dialysis percentages and soy-based formula components to estimate the possible influence of the latter on the dialysability of the elements. Significant correlations were found between citric acid contents and dialysability of Zn and Fe. No correlations were found between protein, ascorbic acid and phytic aci…

Effect of a Milk-Based Fruit Beverage Enriched with Plant Sterols and/or Galactooligosaccharides in a Murine Chronic Colitis Model

The potential anti-inflammatory effect of plant sterols (PS) enriched milk-based fruit beverages (PS, 1 g/100 mL) (MfB) with/without galactooligosaccharides (GOS, 2 g/100 mL) (MfB-G) in an experimental mice model of chronic ulcerative colitis was evaluated. Beverages were orally administered to mice every day by gavage to achieve PS and GOS doses of 35 and 90 mg/kg, respectively, and experimental colitis was induced by giving mice drinking water ad libitum containing 2% (w/v) dextran sulphate sodium (DSS) for 7 days, alternating with periods without DSS up to the end of the study (56 days). MfB beverage showed significant reduction of symptoms associated to ulcerative colitis and improved t…

Gangliosides and sialic acid effects upon newborn pathogenic bacteria adhesion: An in vitro study

The effect of the main gangliosides (GM(1), GM(3), GD(3)) and free sialic acid (Neu5Ac) upon the adhesion of pathogenic bacteria implicated in infant diarrhoea is assessed in vitro using the Caco-2 cell line. Concentrations of the bioactive compounds found in the bioaccessible (soluble) fraction of infant formula and human milk are employed. Bacterial adhesion behaviour included enterotoxigenic Escherichia coli (ETEC), enteropathogenic E.coli (EPEC), Listeria monocytogenes, Salmonella entericaserovartyphi, Shigella sonnei, Campylobacter jejuni and Helicobacter pylori. Three different approaches were assayed: pre-incubation of bacteria and compounds before addition to cells (competition); pr…

Anti-Inflammatory and Cytoprotective Effect of Plant Sterol and Galactooligosaccharides-Enriched Beverages in Caco-2 Cells

Plant sterol (PS) (1 g/100 mL) enriched milk-based fruit beverages with or without galactooligosaccharides (GOS) (1.8 g/100 mL) were used in differentiated Caco-2 cells. Their potential cytopreventive effect against oxidative stress induced by cholesterol oxidation products (COPs) and their anti-inflammatory properties were evaluated. Preincubation (24 h) with bioaccessible fractions from beverages without and with GOS (MfB and MfB-G) completely prevented the COPs (60 μM/4 h) induced oxidative stress independent to GOS presence with exception to calcium influx and GSH content, where a partial protective effect was observed. Besides, MfB produced a significant (p < 0.05) reduction of IL-8 (4…

RP-HPLC Determination of Tiger Nut and Orgeat Amino Acid Contents

The amino acid profile of 11 samples of tiger nuts ( Cyperus esculentusL.) grown in the area of “L'Horta Nord” in Valencia (Spain) and one sample of African origin were determined, along with the amino acid contents of 10 samples of natural orgeat from Valencia. Protein was hydrolysed by hydrochloric acid at 110 °C for 23 h, and amino acids were derivatised with AQC and determined by RP-HPLC with fluorescence detection. The chromatographic conditions were optimised. The analytical parameters (detection and quantification limits, precision and accuracy) showed the method to be sufficiently sensitive and reproducible for determining amino acids resistant to acid hydrolysis in tiger nuts and o…

Relative expression of cholesterol transport-related proteins and inflammation markers through the induction of 7-ketosterol-mediated stress in Caco-2 cells.

Human diets contain sterol oxidation products that can induce cytotoxic effects, mainly caused by cholesterol oxides. However, phytosterol oxides effects have been less extensively investigated. This study evaluates the production of inflammatory biomarkers (IL-1β, IL-8, IL-10, TNFα) and the influence of gene expression transporters and enzymes related to cholesterol absorption and metabolism (NPC1L1, ABCG5/8, HMGCoA, ACAT) produced by 7-ketosterols (stigmasterol/cholesterol) in Caco-2 cells. These effects were linked to intracellular signaling pathways by using several inhibitors. Results showed 7-ketostigmasterol to have a greater proinflammatory potential than 7-ketocholesterol. In non-p…

Phospholipids in Human Milk and Infant Formulas: Benefits and Needs for Correct Infant Nutrition.

The composition of human milk has served as a basis for the development of infant formulas, which are used when breastfeeding is not possible. Among the human milk nutrients, 50% of the total energetic value corresponds to fat, with a high level of fatty acids and 0.2-2.0% present in the form of phospholipids (PLs). The PL contents and fatty acid distribution in PL species have been investigated as bioactive elements for the production of infant formulas, since they offer potential benefits for the optimum growth and health of the newborn infant. The differences in the amount of PLs and in fatty acid distribution in PL species between human milk and infant formulas can imply biologically si…

Revision: Indicadores del deterioro de la calidad proteica y del valor nutritivo de la leche / Review: Indicators of damage of protein quality and nutritional value of milk

The nutritional value of milk can be negatively affected by thermal treatments. The quality of the proteins can be modified as a consequence of a set of reactions, the most important of which are the interactions between protein and carbohydrates, also known as Maillard reactions. These reactions can also occur when the storage conditions of moisture and temperature are unfavorable. The differ ent thermal treatments involved in processing milk (pasteurization, sterilization, drying, etc.) lead to different steps of the Maillard reaction and therefore to the formation of different compounds that can be useful as chemical markers of milk alteration, or more exactly of protein alteration. Est…

Vitamin E as an IgE inhibitor: stability during cold storage of human milk

Human breast milk is recommended as the unique food for neonates based on its known properties. When the production of milk by themother is not sufcient or the mother is not able to feed her child for professional reasons, milk banks or the mothers’ practice ofcollecting their own milk are the existing alternatives for breast-feeding. In both situations cold storage (refrigeration or freezing) can beused in neonatal units, at home and in human milk banks

Impact of plant sterols enrichment dose on gut microbiota from lean and obese subjects using TIM-2 in vitro fermentation model

There are scarce data on plant sterols (PS) and gut microbiota relationship. The purpose of this study is to compare the interaction between PS and gut microbiota through in vitro colonic fermentation studies using a validated system (TIM-2) with a PS-enriched dose (similar to 2 g/day) from two sources (food PS-source ingredient and commercial standard) using microbiota from lean and obese populations. Fecal sterols, short chain fatty acids (SCFA) and microbiota composition were determined by GC/MS, IEC, and 16S-sequencing, respectively.PS-feeding decreased coprostanol and ethylcoprostanol concentration and increased the production of acetate and butyrate (mainly with lean microbiota). In a…

Effects of phytosterol ester-enriched low-fat milk on serum lipoprotein profile in mildly hypercholesterolaemic patients are not related to dietary cholesterol or saturated fat intake

Phytosterols (PS) are recommended to reduce LDL-cholesterol. However, the influence of cholesterol and fat intake on the lipid-lowering effect of PS in mildly hypercholesterolaemia is unclear. Thus, the aim of the present study was to evaluate whether the efficacy of PS is related to the composition of saturated fat and dietary cholesterol intake. Additionally, serum carotenoid content was analysed to evaluate to what extent it was undermined by PS. This was a 3-month randomised, parallel trial with a three-arm design. Patients were divided into three groups: healthy diet (n 24), healthy diet + PS (n 31) and free diet + PS (n 29), receiving 2 g/d of PS. Healthy and free diets were character…

In Vitro Dialyzability of Zinc from Different Salts Used in the Supplementation of Infant Formulas

Seven zinc salts--acetate, chloride, lactate, sulfate, citrate, gluconate, and oxide--were added to milk--and soy-based infant formulas to estimate possible differences in zinc availability depending on the type of salt used. For this purpose, an in vitro method that estimates the dialyzability of the element (i.e., the fraction available for absorption) was applied. Zinc dialyzability is always higher in milk-based products than in soy products, even when the total zinc contents are higher in the latter. The salts can be classified according to the zinc dialyzability in the two types of formulas as follows: oxidegluconate = chloride = lactatecitrate = acetatesulfate. Therefore, according t…

Optimization of selenium determination in human milk and whole blood by flow injection hydride atomic absorption spectrometry.

abstract A flow injection hydride atomic absorption spectrometry (FI-HAAS) method was developed for determining selenium in human milk and whole blood after microwave digestion of the sample. The sample (2 mL human milk or 0.25 mL blood) was introduced into the microwave vessel with 1.5 mL HN03 and 0.25 mL H202 and 300 W (4 min) and 600 W (4 min) were applied. The digestion was completed by heating to 140 C (2-3 h). Se (VI) was reduced to Se (IV) with hydrochloric acid. The instrumental conditions for FI-HAAS (concentrations of reducing agent and carrier acid, flow rate of argon carrier gas, and sample volume injected) were optimized. The detection limit of the proposed method was 0.23 ng/m…

Caseinophosphopeptides exert partial and site-specific cytoprotection against H2O2-induced oxidative stress in Caco-2 cells

Abstract Caseinophosphopeptides can sequester prooxidant metals and scavenge free radicals, and may thus be used as functional food ingredients. The total antioxidant capacity (TEAC and ORAC) of two pools of caseinophosphopeptides (1–3 mg/ml), obtained from casein subjected to simulated gastrointestinal digestion (at two different pH values) and selective precipitation, was evaluated to determine dose–response activity. Pool B (which showed the highest antioxidant capacity due to the presence of more antioxidant amino acids) was used to test its cytoprotective effect against H2O2-induced oxidative stress in Caco-2 cells. Caseinophosphopeptides protected the cells against oxidative damage by…

Effect of caseinophosphopeptides added to fruit beverages upon ferritin synthesis in Caco-2 cells

Ferritin synthesis was evaluated in iron sulphate solutions and in fruit beverages supplemented with iron, with/without zinc in the presence of caseinophosphopeptides (CPPs), based on a system combining simulated gastrointestinal digestion and the Caco-2 cell model. In iron sulphate solutions with/without zinc, the addition of CPPs had no effect upon ferritin synthesis. When CPPs were added to the bioaccessible fraction of fruit beverages supplemented with iron, ferritin synthesis increased in the same proportion as with the addition of milk. The addition of zinc to fruit beverages supplemented with iron and to iron sulphate solutions decreased ferritin synthesis. Nevertheless, in fruit bev…

Lipid peroxidation and antioxidant enzyme activities in patients with type 1 diabetes mellitus

To evaluate oxidative stress in type I diabetes mellitus, two antioxidant enzymes in erythrocytes, copper-zinc superoxide dismutase (SOD EC 1.15.1.1.) and seleno-dependent glutathione peroxidase (GSH-Px; EC 1.11.19), and two indexes of peroxidation in plasma, thiobarbituric acid reactive substances (TBARS) and organic hydroperoxides (OHP), were measured in 118 patients with insulin-dependent diabetes mellitus (IDDM), classified in accordance with the presence or absence of vascular complications and the degree of metabolic control established by the HbA1c level. Ninety healthy subjects made up the control group. According to our results, plasmatic TBARS and OHP concentrations are significan…

Selenium, zinc and copper in plasma of patients with type 1 diabetes mellitus in different metabolic control states

The Studies of selenium (Se), zinc (Zn) and copper (Cu) levels in diabetic patients have led to contradictory findings as the possible relationship between the degree of diabetic control and the changes in mineral contents. In the present study the plasma Cu, Se, and Zn contents of diabetic patients and healthy people were measured and the relationship between these contents and diabetic metabolic control, as determined by glycosylated hemoglobin (HbA1c), was studied. The mean plasma Se content in diabetic patients was significantly lower than in controls (p < 0.01) and a negative correlation between the plasma contents of Se and HbA1c was found. No statistically significant differences in …

Effects of thermal processing and storage on available lysine and furfural compounds contents of infant formulas.

The Maillard reaction-related effects that thermal treatments during the manufacturing process and storage (at 20 and 37 degrees C) have on powdered adapted and follow-up milk-based infant formulas were estimated by measuring the available lysine and furfural compounds contents of raw cow milk used in manufacturing, intermediate products and formulas. A fluorimetric method was used to measure the available lysine contents, and free and total furfural compounds were determined by HPLC. Statistically significant losses in available lysine (about 20%) in the infant formulas with respect to raw milk were found. The storage period did not affect the available lysine contents of adapted formulas …

Calcium bioavailability in human milk, cow milk and infant formulas—comparison between dialysis and solubility methods

Abstract The percentages of total, soluble and dialysable calcium of human milk, cow milk and milk and soy based infant formulas were determined in order to detect possible differences in the calcium bioavailability of the samples. For this purpose an in vitro method was applied to these four calcium sources. The ranking of the analysed samples in terms of calcium bioavailability depends on the criteria applied. Calcium ranked dialysis percentage was: cow milk>human milk>soy based formula>milk based formulas. Calcium ranked solubility percentage was: human milk>cow milk>soy-based formula>milk-based formulas. Comparison of the results of the in vitro assay with the information available on i…

Effect of β-cryptoxanthin plus phytosterols on cardiovascular risk and bone turnover markers in post-menopausal women: a randomized crossover trial.

Abstract Background and aim Post-menopausal women are at higher risk of cardiovascular disease and bone demineralization. Phytosterols (PS) may be used for hypercholesterolemia in some groups and β-cryptoxanthin (β-Cx) displays a unique anabolic effect on bone. Our aim was to assess the changes in cardiovascular and bone turnover markers from the oral intake of β-Cx and PS in post-menopausal women. Methods and results A randomized, double-blind, crossover study with β-Cx (0.75 mg/day) and PS (1.5 g/day), single and combined, was performed in 38 postmenopausal women. Diet was supplemented with 1 × 250 mL milk-based fruit drink/day for 4 weeks with a wash-out period of 4-weeks in between. Ser…

Effect of processing on the bioaccessibility of bioactive compounds – A review focusing on carotenoids, minerals, ascorbic acid, tocopherols and polyphenols

Health benefits of bioactive compounds depend not only on the intake levels but also on their bioavailability (BAv). In vitro methods to simulate gastro-intestinal digestion allow to determine the bioaccessibility (BAcs) of these compounds, as a first step of BAv, and can be used to evaluate the effect of processing on them to design functional foods with increased health-promoting effects. The impact of traditional processing technologies such as thermal treatment and novel emerging non-thermal technologies such as high pressure processing, high-intensity pulsed electric fields and ultrasound on BAcs of bioactive compounds as carotenoids, minerals, ascorbic acid, tocopherols, polyphenols a…

Current methodologies for phytosterol analysis in foods

Abstract Plant sterols (PS) (phytosterols and phytostanols) are bioactive compounds of all vegetable foods where can be found as free sterol alcohols and as conjugates. These latter forms have been less studied, although they may have potential beneficial effects, whereas some PS have several approved health claims, especially in lowering blood cholesterol levels. In this context, it is necessary to establish analytical methods for food authentication, assessing PS health benefits and unfolding future applications. Several extraction methodologies have been employed for the extraction of PS from food matrixes (usually solvent extraction and saponification) although solid-phase extraction, s…

Evolution of available lysine and furosine contents in milk-based infant formulas throughout the shelf-life storage period

The evolution of the Maillard reaction (MR) by measuring the available lysine and furosine (FUR) contents in adapted and follow-up powdered milk-based infant formulas over the shelf-life storage period, at 20 and 37 °C, was studied. Available lysine and FUR contents were determined by fluorimetry and high-performance liquid chromatography respectively. Statistically significant differences were found between adapted and follow-up infant formulas with respect to the available lysine and FUR contents. Available lysine contents decreased significantly throughout the storage time, and the contents at 37 °C were lower than at 20 °C. A statistically significant increase in FUR contents was observ…

Evaluation of in vitro iron bioavailability in free form and as whey peptide-iron complexes

Abstract Finding alternatives for food fortification in a bioavailable form of iron is needed because iron deficiency leads to several diseases. Iron solubility and in vitro iron absorption were evaluated in free and complexed forms, as iron salts or peptide-iron complexes. Whey peptide-iron complexes were synthesized with various ligands (whey protein hydrolysate; its fractions >5 kDa and 85%), only complexes that were synthesized with low-molecular-mass peptides (

Calcium dialysability as an estimation of bioavailability in human milk, cow milk and infant formulas

Abstract The calcium dialysability of human milk, cow milk and infant formulas is estimated by applying the in vitro method (Miller, Schricker, Rasmussen, & Van Campen, (1981). American Journal of Clinical Nutrition, 34, 2248–2256) slightly modified, as a measure of its bioavailability. The influence of the protein composition of infant formula samples on calcium bioavailability is also studied. Whole cow milk, a pool of human milk and 18 commercial infant formulas of 6 different types are analysed. The highest values of calcium dialysability (mg Ca/100 ml infant formula) correspond to premature (13.6) and follow-up formulas (11.8) and the lowest ones to adapted formulas (3.7); the latter v…

Impact of colonic fermentation on sterols after the intake of a plant sterol-enriched beverage: A randomized, double-blind crossover trial

Summary Background Cholesterol microbial transformation has been widely studied using in vitro fermentation assays, but less information is available on the biotransformation of plant sterols (PS). The excretion percentage of animal sterols (AS) (67–73%) is considerably greater than that of PS (27–33%) in feces from healthy humans following a Western diet. However, a lower content of AS in feces from subjects following a vegetarian, vegan or low-fat animal diet has been seen when compared to omnivorous subjects. Although only one human study has reported fecal sterol excretion after the consumption of PS-enriched food (8.6 g PS/day), it was found that the target group showed an increase in …

Impact of processing on mineral bioaccessibility/bioavailability

Abstract A review is made of the influence of processing on the bioaccessibility/bioavailability of macrominerals (Ca, P, Mg and K) and microminerals (Fe, Cu, Zn and Se). In vegetable foods, household processes (dehulling, soaking, germination and fermentation) alone or with thermal processing increase mineral bioaccessibility, mainly referred to Fe, Cu, Zn, Se and Ca. The application of thermal processing to vegetable foods has different effects upon mineral bioaccessibility, with an overall increase in Ca and Fe and a decrease in Se. In turn, there is a general positive impact upon mineral bioaccessibility in animal foods when conventional thermal processing is used with shorter times and…

Bioaccessibility of tocopherols, carotenoids, and ascorbic acid from milk- and soy-based fruit beverages: Influence of food matrix and processing

A study was made of the effect of high-pressure processing (HPP) and thermal treatment (TT) on plant bioactive compounds (tocopherols, carotenoids, and ascorbic acid) in 12 fruit juice-milk beverages and of how the food matrix [whole milk (JW), skimmed milk (JS), and soy milk (JSy)] modulates their bioaccessibility (%). HPP (400 MPa/40 °C/5 min) produced a significant decrease in carotenoid and ascorbic acid bioaccessibility in all three beverages and maintained the bioaccessibility of tocopherols in JW and JS while decreasing it in JSy. TT (90 °C/30 s) produced a significant decrease in tocopherol and carotenoid bioaccessibility in all three beverages and increased the bioaccessibility of …

Review: Determination of Vitamin D in Dairy Products by High Performance Liquid Chromatography

This work reviews the methods used for the determination of vitamin D in some dairy products (milk and infant formulas) by high performance liquid chromatography (HPLC). The low vitamin D contents and the presence of interfering compounds require sample treatment and purification of the extract. The advantages and drawbacks of hot and cold saponification, direct extraction and different types of extract purification are also discussed, taking into account the lack of vitamin D stability by heating, exposure to light and oxidation. With respect to chromatographic determination, the mode (normal or reverse phase), type of column (microcolumn or conventional) and detection system (UV, electro…

Lead, cadmium and chromium content of edible vegetables grown in three different agricultural areas

(1990). Lead, cadmium and chromium content of edible vegetables grown in three different agricultural areas. Food Additives & Contaminants: Vol. 7, No. sup1, pp. S22-S25.

Effect of Caseinophosphopeptides from αs- and β-Casein on Iron Bioavailability in HuH7 Cells

International audience; Two pools of caseinophosphopeptides (CPPs) obtained from αs- and β-casein fractions (α-CPPs and β-CPPs) were characterized. A total of 16 CPPs were identified in the α-CPPs pool, 9 of them derived from αs1-casein and 7 from αs2-casein. A total of 18 CPPs were identified in the β-CPPs pool. Four of the identified CPPs contained the characteristic phosphoseryl-glutamic acid cluster SpSpSpEE. Calcein assay was used to compare the iron-binding capacity of the α- and β-CPPs pools. At the concentration of 12.5 μM CPPs used in the iron bioavailability assays, β-CPPs pools show greater iron-binding capacity than α-CPPs pools. HuH7 human hepatoma cells show many differentiate…

Sialic acid (N-acetyl and N-glycolylneuraminic acid) and ganglioside in whey protein concentrates and infant formulae

Abstract Sialic acid and gangliosides content and profiles were analyzed in infant formulae, whey protein concentrates and human milk. In infant formulae, N-acetylneuraminic (Neu5Ac) and N-glycolylneuraminic (Neu5Gc) acid ranged from 147.6–199.7 to 3.3–8.3 mg L −1 , in whey protein concentrate from 1.6–2.4 g 100 g −1 to 2.8–20.2 mg 100 g −1 and in human milk from 299.9 to 2.1 mg L −1 . Gangliosides ranged from 0.25 to 2.29 mg lipid-bound sialic acid L −1 in reconstituted infant formula, the main gangliosides being GD 3 (73.3–55.5%), GM 3 (3.5–36.6%) and GT 3 (1.4–14.1%) and O-acetyl-GD 3 (5.3–18.9%). In whey protein concentrates, 0.7–55.6 mg lipid-bound sialic acid 100 g −1 were found with …

Selenium contents of human milk and infant formulas in Spain.

The selenium content of Spanish human milk samples and different milk-based and soy-based infant formulas has been estimated by using a flow injection hydride atomic absorption spectrometric method after microwave digestion of the organic matter. Mean values of 11.4 +/- 3.7 and 10.7 +/- 4.6 ng/ml for colostrum and transitional milk, 8.4 +/- 3.4 and 5.3 +/- 1.9 ng/ml for mature milk at 1 month and up to 2 months respectively, was obtained. These values are close to those reported by others authors in Europe, and lower than the ones from the US, Japan and Korea. Selenium contents of the analyzed infants' formulas ranged from 2.7 to 9.6 ng/ml and from 1.8 to 7.5 ng/ml for soy and milk-based in…

Plant sterols from foods in inflammation and risk of cardiovascular disease: a real threat?

High dietary intakes of cholesterol together with sedentary habits have been identified as major contributors to atherosclerosis. The latter has long been considered a cholesterol storage disease; however, today atherosclerosis is considered a more complex disease in which both innate and adaptive immune-inflammatory mechanisms as well as bacteria play a major role, in addition to interactions between the arterial wall and blood components. This scenario has promoted nutritional recommendations to enrich different type of foods with plant sterols (PS) because of their cholesterol-lowering effects. In addition to cholesterol, PS can also be oxidized during food processing or storage, and the…

Evaluation of Antimony, Cadmium and Lead Levels in Vegetables, Drinking and Raw Water from Different Agricultural Areas

Abstract Lead and cadmium levels in edible vegetables and antimony, lead and cadmium in drinking and raw waters from three agricultural areas exposed to different levels of environmental pollution (1-high industrial pollution, 2-high urban pollution, 3-standard low industrial and urban pollution) are determined. The organic matter is destroyed by repeated attack with nitric acid. Cadmium and lead are determined by graphite furnace atomic absorption spectrometry (GFAAS) and antimony by hydride generation atomic absorption spectrometry (HGAAS). When the results obtained for three different areas are compared, differences between cadmium and lead contents in vegetables are observed. Waters are…

Iron and zinc bioavailability in Caco-2 cells: Influence of caseinophosphopeptides

Abstract A study has been made of the influence of two pools of caseinophosphopeptides (CPPs) obtained from α s - and β-casein (CN) fractions, and of three specific CPPs (β-CN(1–25)4P, α s1 -CN(64–74)4P and α s2 -CN(1–19)4P), on iron bioavailability (ferritin synthesis) and zinc bioavailability (retention, transport and uptake of zinc) in Caco-2 cells. α-CPP and β-CPP pools did not improve ferritin synthesis, but the three specific CPPs showed an increase in ferritin synthesis in Caco-2 cells versus iron sulphate, β-CN(1–25)4P being the most effective. In relation to zinc bioavailability, α-CPPs, β-CPPs, α s1 -CN(64–74)4P and β-CN(1–25)4P increased zinc uptake. However, this increase was of…

Liquid chromatographic determination of Vitamin D3 in infant formulas and fortified milk

Abstract An isocratic reverse-phase liquid chromatographic (LC) method with electrochemical (EC) detection has been developed and validated for determining Vitamin D 3 in fortified milk and infant formulas. LC–EC determination provides linear responses in the range from 0.03 to 0.7 μg Vitamin D 3 /ml, with inter- and intra-day variations (R.S.D.%) of 4.1 and 4.4, respectively, and detection and quantification limits of 0.012 ng in assay (48 ng/100 g of sample) and 0.039 ng in assay (156 ng/100 g of sample), respectively. Application of the method to a set of infant formulas and fortified milk confirmed its usefulness.

Mind the gap—deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites—a position paper focusing on carotenoids and polyphenols

This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence.-- et al.

Casein phosphopeptides released by simulated gastrointestinal digestion of infant formulas and their potential role in mineral binding

Abstract Adapted and follow-up milk-based infant formulas were subjected to gastrointestinal digestion simulating physiological conditions. The naturally occurring casein phosphopeptides (CPPs) generated were fractionated by anion exchange high-performance liquid chromatography and sequenced by tandem mass spectrometry. In both infant formula digests, a total of 19 CCPs from bovine casein were identified, of which 7 corresponded to α s1 -casein and 12 to α s2 -casein. Most CPPs had the cluster sequence SpSpSpEE, representing the binding sites for minerals. The distribution of calcium, iron and zinc content in CPP fractions eluted from the anion exchange column was also studied. The results …

Fluorescence, Browning Index, and Color in Infant Formulas during Storage

Free and total fluorescent compounds, browning index, and color formation were measured in milk-based powdered infant formulas (IF) during 2 years of storage at 20 and 37 degrees C. The excitation spectra from 415 nm emission show three peaks (ex lambda1 = 270 nm, lambda2 = 325/315 nm, lambda3 = 350 nm) and from 347 nm excitation two emission peaks (415 and 520 nm), and no wavelength shifts were observed. Temperature and time of storage exert in general no significant effect on the development of fluorescence emission intensity and browning index. However, an important increase in pentodilysine was recorded-probably because of the iron and ascorbic acid contents of the samples-as well as in…

Antioxidant effect of casein phosphopeptides compared with fruit beverages supplemented with skimmed milk against H2O2-induced oxidative stress in Caco-2 cells

Abstract Casein phosphopeptides (CPPs) have been proposed as potential dietary antioxidants on designing new functional products. A fruit beverage, with/without milk, was subjected to in vitro digestion. Caco-2 cultures were preincubated with soluble fractions or isolated CPPs, the latter obtained from skimmed milk. The mitochondrial activities (MTT test), intracellular GSH and GSH-reductase activity (GSH-Rd), cell cycle analysis and RNA distribution in cycle phases were studied after inducing oxidative stress status (5 mM H2O2). MTT conversion was better preserved by soluble fractions of fruit beverages, either with or without milk. GSH concentration was equally decreased, and GSH-Rd was i…

Protective effect of bioaccessible fractions of citrus fruit pulps against H2O2-induced oxidative stress in Caco-2 cells

Fruit pulps from Navel (N) and Cara Cara (CC) oranges, and Clementine mandarin freshly harvested (M) and refrigerated stored (M12) were used to evaluate the cytoprotective effect of their bioaccessible fractions (BF) against H2O2-induced oxidative stress in Caco-2 cells. BF of samples preserved viability vs. H2O2 treated cells, reaching values similar to controls. Lipid peroxidation was reduced to levels of control cells, but M did not reach control values. ROS and mitochondrial membrane potential changes (Δψm) values were reduced compared with H2O2 treated cells, but without achieving control levels. A significant reduction in cell proportions in G1 phase and a significant increase in sub-…

Effectiveness of microwave based digestion procedures for the demineralization of human milk and infant formulas prior to fluorometric determination of selenium

The use of two types of microwave oven, one domestic (A) and the other specially designed for laboratory (B) for microwave-based digestion, to destroy the organic matter in milk and infant formulas prior to fluorometric determination of selenium is studied in order to check their applicability and reliability. In both systems the best results were obtained using the acid mixture HNO3—H2O2, and additional treatment with perchloric acid (60%) in a Thermoblock. The application of two different microwave-based digestion procedures to infant formulas was free of interferences. In the case of human milk, it was necessary to use the standard addition method. Values obtained for detection and quant…

In-vitro antioxidant capacity and cytoprotective/cytotoxic effects upon Caco-2 cells of red tilapia (Oreochromis spp.) viscera hydrolysates.

Abstract The antioxidant capacity of red tilapia viscera hydrolysates (RTVH) with different degrees of hydrolysis (DH) as well as their ultrafiltration membrane fractions, were analyzed using different chemical assays. Their protective effects against oxidative stress were evaluated using H2O2-stressed human intestinal differentiated Caco-2. The highest antioxidant capacity was obtained with a DH of 42.5% (RTVH-A) and its

Relationship between cobalt, copper and zinc content of soils and vegetables

The relationship between cobalt, copper and zinc content of soils and the vegetables grown in them is discussed. Samples of soil and edible vegetables were taken from 15 different sites, corresponding to four agricultural areas exposed to different degrees of environmental pollution: high industrial and traffic, high industrial and urban, and low industrial and urban pollution. Elements were determined by atomic absorption spectroscopy. Variance analysis (ANOVA) was applied to cobalt, copper and zinc content of vegetables and soils in order to detect significant differences among soils of different areas and the vegetables grown there. The possible relationship between the heavy metal conte…

Dietary phytochemicals in the protection against oxysterol-induced damage.

The intake of fruits and vegetables is associated with reduced incidence of many chronic diseases. These foods contain phytochemicals that often possess antioxidant and free radical scavenging capacity and show anti-inflammatory action, which are also the basis of other bioactivities and health benefits, such as anticancer, anti-aging, and protective action for cardiovascular diseases, diabetes mellitus, obesity and neurodegenerative disorders. Many factors can be included in the etiopathogenesis of all of these multifactorial diseases that involve oxidative stress, inflammation and/or cell death processes, oxysterols, i.e. cholesterol oxidation products (COPs) as well as phytosterol oxidat…

Bioavailability of plant sterol-enriched milk-based fruit beverages: In vivo and in vitro studies

Abstract This study for the first time compares the in vivo (response in serum from individuals of an interventional study) and in vitro effects (bioaccessibility determined from simulated gastrointestinal digestion) of two plant sterol (PS)-enriched milk-based fruit beverages (with and without tangerine fruit juice rich in β-cryptoxanthin (β-Cx)) in order to assess their suitability as PS-enriched food matrixes, and the possible interactions between the two bioactive compounds (β-Cx and PS) that might affect their absorption. The randomized, double-blind, crossover study (performed in 36 postmenopausal women) showed the β-sitosterol and campesterol serum concentrations after four weeks of …

Evaluation of the cytotoxic effect of 7keto-stigmasterol and 7keto-cholesterol in human intestinal (Caco-2) cells

The biological implications of cholesterol oxidation products have been investigated, though research on plant sterol oxidation products is scarce and in some cases contradictory. The cytotoxicity of 7keto(k)-stigmasterol versus 7keto(k)-cholesterol at different concentrations (0-120 μM) and incubation times (4-24h), in intestinal epithelial cells (Caco-2 cells) was evaluated. The 3-[4,5-dimethylthiazol-2-yl]-2,3-diphenyl tetrazolium bromide and neutral red uptake tests, mitochondrial membrane potential (ΔΨm), and relative DNA and RNA contents in the cell cycle phases were determined. Possible interaction effects between 7k-derivatives or non-oxidized stigmasterol were monitored. Endo/lysos…

Fluorescence and color as markers for the Maillard reaction in milk–cereal based infant foods during storage

Abstract Free and total fluorescence compounds and color formation were measured in three different milk–cereal based infant foods stored at 25, 30 and 37 °C for 9 months to evaluate the advanced and final stages of the Maillard reaction. Milk–cereal infant foods containing honey (B) or fruits (C) had fluorescent values higher than sample (A) without them. This difference could be ascribed to the higher monosaccharide (fructose and/or glucose) content of (B) and (C), which could increase susceptibility to the Maillard reaction. However, for color increase (ΔE), no significant differences (p

Kinetics of ascorbic acid degradation in fruit-based infant foods during storage

The kinetics of ascorbic acid (AA) degradation in a fruit-based beikost product added with AA were determined after storage at 4, 25, 37 and 50 °C during 4, 8, 12, 16 and 32 weeks in plastic polypropylene/ethylenevinyl alcohol vacuum packaging. It was confirmed that AA degradation followed an Arrhenius first-order kinetics, with an activation energy of 20.11 ± 0.33 kcal mol−1. No AA losses at 4 °C were recorded during the entire storage period. In contrast, a time - and temperature - dependent decrease (p the degradation rate decreasing from 50 °C to 25 °C, as expected. AA percentage retention at the end of storage ranged between 6.4% (50 °C/16 weeks) and 100.9% (4 °C/32 weeks).