chlorogenic-acid and procyanidin

Pulsed electric fields (PEF) have arisen as a promising tool for enhancing plant-based food bioactive compounds, although side effects on quality attributes might compromise consumer acceptance. This work was aimed at filling the gap in the understanding of whole effects of PEF on apple phenolic compounds profile and quality parameters. Treatment specific energy was a critical factor affecting phenolic profile and quality attributes, which in turn varied from 0 to 24 h after treatment. Treatments at 1.8 and 7.3 kJ kg

Topics: Antioxidants; Biflavonoids; Catechin; Chromatography, High Pressure Liquid; Coumaric Acids; Flavonoids; Flavonols; Food Quality; Fruit; Malus; Phenols; Proanthocyanidins; Quinic Acid; Spectrometry, Mass, Electrospray Ionization

This study attempts to elucidate the secondary metabolite profiles of Ficus lyrata leaves and fruits grown in Egypt. Non-targeted metabolite profiling via ultra performance liquid chromatography (UPLC)-qTOF-MS was used to identify various chemical classes in F. lyrata fruits and leaves (i.e. flavonoids, phenolic acids and fatty acids) analysed by chemometrics. A total of 72 metabolites were evaluated via a UPLC-qTOF-MS-based metabolomic study. Seventeen flavonoids were characterised and tentatively identified with the main constituents being catechins/procyanidins, O- and C-linked flavonoid glycosides. The major procyanidins were dimers and trimers comprising (epi)catechin and (epi)afzelechin units, whereas the predominant flavones were C-glycosides of luteolin and apigenin. Aside from these major flavonoid classes, a group of benzoic acids, caffeoylquinic acids, fatty acid and sphingolipids were also annotated. This study provides the most complete map for polyphenol distribution in F. lyrata leaves and fruits and the basis for future investigation of its fruits nutritional value or possible nutraceutical uses.

Topics: Apigenin; Benzoates; Biflavonoids; Catechin; Chromatography, High Pressure Liquid; Chromatography, Liquid; Egypt; Fatty Acids; Ficus; Flavones; Flavonoids; Fruit; Glycosides; Molecular Structure; Phenols; Plant Leaves; Polyphenols; Proanthocyanidins; Quinic Acid; Spectrometry, Mass, Electrospray Ionization; Sphingolipids

The rate of consumption of dissolved oxygen by apple polyphenol oxidase in cider apple juices did not correlate with polyphenol oxidase activity in the fruits and decreased faster than could be explained by the decrease of its polyphenolic substrates. The kinetics parameters of a crude polyphenol oxidase extract, prepared from apple (Braeburn cultivar), were determined using caffeoylquinic acid as a substrate. Three apple procyanidin fractions of n 80, 10.5, and 4 were purified from the parenchyma of cider apples of various cultivars. Procyanidins, caffeoylquinic acid, (-)-epicatechin, and a mixture of caffeoylquinic acid and (-)-epicatechin were oxidized by reaction with caffeoylquinic acid o-quinone in order to form oxidation products. All the fractions were evaluated for their inhibitory effect on PPO activity. Native procyanidins inhibited polyphenol oxidase activity, the inhibition intensity increasing with n. The polyphenol oxidase activity decreased by 50% for 0.026 g/L of the fraction of n 80, 0.17 g/L of the fraction of n 10.5, and 1 g/L of the fraction of n 4. The inhibitory effect of oxidized procyanidins was twice that of native procyanidins. Oxidation products of caffeoylquinic acid and (-)-epicatechin also inhibited polyphenol oxidase.

Topics: Beverages; Biflavonoids; Catechin; Catechol Oxidase; Chromatography, High Pressure Liquid; Enzyme Inhibitors; Flavonoids; Fruit; Kinetics; Malus; Oxidation-Reduction; Phenols; Polyphenols; Proanthocyanidins; Quinic Acid