Search results for "ACID"

Enzyme inactivation and evaluation of physicochemical properties, sugar and phenolic profile changes in cloudy apple juices after high pressure proce…

2019

The effect of high pressure processing (HPP) (200–600 MPa/5–45°C/1–15 min) on the enzyme activity and some quality parameters of cloudy apple juice during subsequent storage (4°C for 12 weeks) was investigated. Statistical analysis showed that pressure, temperature, and time had a significant effect (p < 0.05) on tissue enzyme activity, decreasing the activity of polyphenol oxidases (PPO) and peroxidases (POD). No significant changes in physicochemical parameters (pH, total soluble solids, sugars, and vitamin C) were observed after HPP treatments. The main polyphenols detected in apple juice were dichydrochalcones, being phloridzin the predominant (48.8 mg/L), and flavanols, with the highes…

Evaluation of microbiological and physico‐chemical parameters of retail ready‐to‐eat mono‐varietal salads

2019

An integrated microbiological and physico-chemical approach was applied to evaluate the decay of mono-varietal ready-to-eat escarole (Cichorium endivia var. latifolium) and red chicory (Cichorium intybus L. var. foliosum Hegi) during refrigeration. Total mesophilic microorganisms, including pseudomonads, and total psychrotrophic microorganisms were detected at high numbers in all samples just after packaging and at the expiry date. The dominant microbial populations analyzed by classical culture-dependent methods belonged to Pseudomonas and yeasts. Illumina sequencing identified Janthinobacterium lividum and Pseudomonas veronii as main species. Regarding the physico-chemical quality between…

Anti-inflammatory effect of grape (Vitis vinifera L.) seed extract through the downregulation of NF-κB and MAPK pathways in LPS-induced RAW264.7 macr…

2019

Abstract The aim of this study was to enhance the anti-inflammatory potential of grape (Vitis vinifera L.) seed extract (GSE) in lipopolysaccharide (LPS) activated murine macrophage RAW264.7 cells. The total phenol content of GSE was 112.66 mg GAE/g in Carignan, 142.33 mg GAE/g in Merlot and 161.66 mg GAE/g in Syrah. GSE contained 12 phenol compounds including 8 flavan-3-ols (catechin, epigallocatechin gallate, epicatechin, procyanidin b1, procyanidin b4, procyanidin b2), 3 flavonols (kaempferol, myricitrinand quercetin) and only 1 phenolic acid (gallic acid). GSE significantly suppressed the gene expression and protein secretion of tumor necrosis factor-α (TNF-α), interleukin (IL-6), induc…

Gamma Irradiation and Fermentation

2016

This chapter discusses the applications of gamma irradiation technology for food safety, its nutritional implications, and its involvement in fermentation processes. Gamma irradiation has become an alternative technology for food sterilization due to its nonthermal character, thus replacing the conventional heating processes. Several driving forces are propelling the need of γ-irradiation forward for food applications. Besides food preservation, γ-irradiation is taking place for novel applications, especially involving the enhancement of food fermentation processes, by directly irradiating the medium, or generating performant genetically modified strains.

Fruit and juice characteristics of 30 accessions of two cactus pear species (Opuntia ficus indica and Opuntia megacantha) from different regions of M…

2016

Abstract The fruit and fruit juice of 30 accessions of cactus pear (23 accessions of Opuntia ficus indica and 7 accessions of Opuntia megacantha ) grown in different regions of Morocco were analyzed. The morphological characteristics of the fruit and the pH, titratable acidity, contents of soluble solids, total carotenoids, reducing sugars, and vitamin C in the fruit juice were analyzed. Fruit length, fresh fruit weight, fresh skin weight, fresh skin to fruit ratio, dry skin weight, and water content in the skin varied significantly within and between the two species. There were significant differences among accessions in most of the fruit juice characteristics. The ranges of measured value…

Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

2016

Summary The aim of the work was to evaluate the profile of free amino acids (FAA) as the possible precursors of biogenic amines (BAs) in different varieties and hybrid lines of Lupinus luteus and Lupinus angustifolius and its changes during fermentation. Lupins have high amounts of FAA, and therefore, significant contents of BAs by the action of bacterial amino acid decarboxylases can be formed. In view of this, the effect of three Pediococcus pentosaceus strains KTU05-8, KTU05-9 and KTU05-10 on BA formation during lupin fermentation was studied. The formation of BAs was monitored during 48-h fermentation at solid-state conditions and compared with that in samples after submerged fermentati…

Evaluating the impact of vegetal and microalgae protein sources on proximate composition, amino acid profile, and physicochemical properties of ferme…

2018

Influence of pulsed electric field processing on the quality of fruit juice beverages sweetened with Stevia rebaudiana

2017

Abstract A fruit juice-stevia beverage was processed using pulsed electric fields (PEF), a non-thermal preservation technology, with the purpose of investigating the feasibility of PEF for bioactive compounds and steviol glycosides enhancement and its impact on physicochemical properties. Variable ranges of response surface methodology were 20–40 kV/cm (electric field strength), 100–360 μs (treatment time) and 0–2.5% (w/v) stevia. After PEF, ascorbic acid was retained by more than 74%. Some of the analyzed PEF treatments resulted in an enhancement of total anthocyanins and carotenoids. The best results for rebaudioside A/stevioside ratio were obtained when PEF was applied at 30 kV/cm for 23…

Influence of the marine feeding area on the muscle and egg fatty-acid composition of Atlantic salmonSalmo salarspawners estimated from the scale stab…

2017

Fatty acids in muscle tissue and eggs of female Atlantic salmon Salmo salar spawners were analysed to evaluate the dietary quality of their final feeding areas in the Baltic Sea. The final likely feeding area was identified by comparing stable carbon and nitrogen isotope composition of the outermost growth region (final annulus) of scales of returned S. salar with that of reference S. salar caught from different feeding areas. Some overlap of stable-isotope reference values among the three areas, in addition to prespawning fasting, decreased the ability of muscle tri-acylglycerols to discriminate the final likely feeding area and the area's dietary quality. Among three long-chained polyunsa…

Huanglongbing modifies quality components and flavonoid content of ‘Valencia’ oranges

2015

BACKGROUND: In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of ‘Valencia’ oranges, fruit from non-infected trees (control), from infected trees but symptom-less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography. RESULTS: Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were small…