Search results for "Ingredient"

DUAL APPLICATION OF DIVALENT ION-ANCHORED CATALYST: BIODIESEL SYNTHESIS AND PHOTOCATALYTIC DEGRADATION OF CARBAMAZEPINE

2019

Determination of unsaturation grade and trans isomers generated during thermal oxidation of edible oils and fats by FTIR

1999

Abstract The oxidative deterioration of culinary oils and fats during episodes of heating associated with normal usage (80°C–300°C, 20–40 min) was monitored by FTIR spectroscopy. The thermal oxidation of polyunsaturated fatty acids during heating was studied by the determination of unsaturation percentage and trans isomers at various temperatures and heating times. Oils frequently used in food frying such as olive oil, sunflower oil, corn oil and seeds oil (sunflower, safflower and canola seed), and lard were studied. The Absorbance Correction Method is proposed to correct the spectral interference and allows the analytic use of signal which would not be initially valid for quantitative ana…

Analytical evaluation of polyunsaturated fatty acids degradation during thermal oxidation of edible oils by Fourier transform infrared spectroscopy

1998

The oxidative deterioration of polyunsaturated fatty acids (PUFAs) in culinary oils and fats during episodes of heating associated with normal usage (80-300 degrees C, 20-40 min) has been monitored by Fourier transform infrared spectroscopy (FTIR). The thermal oxidation of PUFAs is a free radical chain reaction, in which hydroperoxides are generally recognized as the primary major products. Hydroperoxides of PUFAs are easily decomposed into a very complex mixture of secondary products with the decrease in unsaturation. The oxidative advance of PUFAs during heating was studied by the determination of unsaturation percentage at different temperatures and heating times. Oils frequently used in…

Tin compounds interaction with membranes of egg lecithin liposomes.

2007

This work is a continuation of earlier research concerning the influence of tin compounds on the dynamic properties of liposome membranes produced with lecithin hen egg yolks (EYL). The experiments were carried out at room temperature (about 25 ∞C). Four tin compounds were chosen, including three organic ones, (CH3)4Sn, (C2H5)4Sn and (C3H7)3SnCl, and one inorganic, SnCl2. The investigated compounds were admixed to water dispersions of liposomes. The content of the admixture changed within the range 0 mol-% to 11mol-% in proportion to EYL. Two spin probes were used in the experiment: 2,2,6,6-tetramethylpiperidine- 1-oxyl (TEMPO) and 2-ethyl-2-(15-methoxy-15-oxopentadecyl)-4,4-dimethyl-3-oxaz…

Infusion mass spectrometry as a fingerprint to characterize varnishes in oil pictorial artworks.

2007

Mass spectrometry methodology to characterize drying oil used as binding media and varnishes in pictorial artworks, prior to conservation or restoration treatment, is proposed. The analytical treatment requires prior basic hydrolysis of the samples to release the fatty acids : caprylic, pelargonic, capric, sebacic, azelaic, suberic, eicosanoic, lauric, mirystic, palmitic, linolenic, linoleic, oleic and stearic, followed by separation from the matrix by a hexane/water extraction. After removing the solvent, the remaining solid is dissolved in potassium hydroxide, propanol and methanol. The mixture is directly infused into a mass spectrometer without any previous derivatization or separation …

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

2019

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 …

Bimodal Effect of Amphiphilic Biocide Concentrations on Fluidity of Lipid Membranes

1996

Abstract Using the spin label method (ESR) it has been shown that biologically active, amphiphilic compounds (quaternary ammonium salts -AS) containing polar heads with single and double positive charge caused, at low concentrations, decrease fluidity of liposome membranes formed with egg yolk lecithin (EYL). At higher concentrations an increase in fluidity was observed. With compounds having a single positive charge minimum fluidity of membrane structure occurs in the range of 1 to 3%, with compounds containing double positive charge -in the range of 4 -6 % . That effect does not depend on polar head size and length of alkyl chains of the AS used. Analysis of the electrostatic interaction …

Fluidity of liposome membranes doped with organic tin compounds: ESR study.

2008

The kinetics of change in the fluidity of liposome membranes, obtained in the process of sonication of Egg Yolk Lecithin (EYL), with the admixture of organic tin compounds, was investigated. Five compounds were selected for the research: three differed in the length of hydrocarbon chains, (CH(3))(4)Sn, (C(2)H(5))(4)Sn, and (C(3)H(7))(3)SnCl, whereas two differed in the number of aromatic rings, (C(6)H(5))(2)SnCl(2) and (C(6)H(5))(3)SnCl. The concentration of the compounds in proportion to EYL was 2 mol-%. Electron Spin (paramagnetic) Resonance (ESR) was applied using two spin probes TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) and 16-DOXYL-stearic acid methyl ester (2-ethyl-2-(15-methoxy-15…

Study of the impact of wheat flour type, flour particle size and protein content in a cake-like dough: Proton mobility and rheological properties ass…

2012

International audience; The study of food products is always a challenge due to the number of components involved and the interactions that may occur between them. Water is a particular ingredient which interacts with all hydrophilic compounds, although affinities may differ for limiting water amount. During this study, results obtained using H-1 NMR on cake dough were compared in terms of the effects of flour type (soft or medium hard), the addition of gluten (5%-20%) and the use of soft flour fractions (flour particle fractions smaller or larger than 50 mu m). T-2 values and the signal intensities of different proton populations were studied as a function of the wheat protein contents of …

Effect of carboxymethyl cellulose concentration on rheological behavior of milk and aqueous systems. A creep and recovery study

2009

Carboxymethyl cellulose (CMC) is an anionic polysaccharide used mainly as stabilizer and thickener agent. The purpose of this study was to investigate the effect of CMC concentration on viscoelasticity of dairy and aqueous model systems through the analysis of creep and recovery tests. The viscoelastic properties of different concentrations of CMC (0.75, 1.00, 1.25, and 1.50% w/w) in two milk systems (skimmed milk and whole milk) were compared with those of the same concentration of biopolymer in aqueous solution. Creep curves were fitted to a six parameter mechanical model (Burger + Kelvin-Voigt), whereas an empirical equation was used for recovery. The creep and recovery properties of sam…