Authors:Thouraya Majoul, Faten Bouabdallah, Majdi Hammami, Hajer Satouri, Olfa Tabbene, Imen B. Slimen, Salem Elkahoui, Férid Limam, Ezzedine Aouani; Faten Bouabdallah, Majdi Hammami, Hajer Satouri, Olfa Tabbene, Imen B. Slimen, Salem Elkahoui, Férid Limam, Ezzedine Aouani Abstract: Thousands of polyphenolic compounds have been identified in various plants. Recently, a number of studies showed that beneficial effects of grapes are related to the presence of polyphenols, with multiple biological activities. The aim of this study was to compare the polyphenol profiles as well as biological activities of the seeds of four Tunisia cultivated grape cultivars, syrat, merlot, cabernet sauvignon and carignan. The total phenolic content of seed extracts varied between varieties and seemed to be correlated to the scavenging activity. Preliminary antibacterial results showed a good growth inhibitory activity of syrat cultivar against Staphylococcus epidermidis. To our knowledge, this is the first of such study being performed on this bacterium, known as a leading cause of Tunisian hospital-acquired infections. Gas Chromatography Mass Spectrometry analysis identified 20 polyphenol components, flavonoids being the most abundant in all extracts, followed by phenolic acids, resveratrol, tyrosol, and syringaldehyde. We also noticed a deficiency of three phenolic acid compounds (salicylic acid methyl ester, ferulic acid, Sinapic acid) as well as a flavonoid one (myricetin) in merlot cultivar, which could be responsible for its low antioxidant activity. These results will help in the selective exploitation of the seeds obtained from winemaking wastes, as well as in further pharmacological and/or in vivo investigations. PubDate: 2019-05-19 DOI: 10.33687/jfcn.007.01.2835 Issue No:Vol. 7, No. 1 (2019)
Authors:Pedro A. Prieto, Michael B. Miklus, Cynthia M. Barber, Steven M. Tennyson; Michael B. Miklus, Cynthia M. Barber, Steven M. Tennyson Abstract: Analytical methods to assess the content of free carbohydrates in solution range from simple tests of reductive power to combinations of chromatography and mass spectrometry. Soluble carbohydrates such as lactose, maltose, fructooligosaccharides, and galactooligosaccharides are commonly found in infant formulas either as sources of energy or soluble fibers. On the other hand, a rich repertoire of lactose-based carbohydrates occurs naturally in human milk. The advent of novel biosynthesis technologies resulted in the availability of human milk oligosaccharide structures that are being used as ingredients in infant formulas. Notably, 2’Fucosyllactose has been tested in preclinical and clinical studies to determine its safety and to explore its potential health benefits in the context of pediatric nutrition. Several chromatographic methods for the analysis of human milk oligosaccharides have been published and, the main challenge associated with 2’Fucosyllactose quantitation has been to improve its resolution from lactose, which is present at concentrations around 70 g/l in both, infant formula and human milk. We developed a high-performance anion exchange chromatography method to detect and quantify 2’ Fucosyllactose in the presence of lactose by expanding the elution time between these saccharides. We validated the analytical procedure which behaved linearly (average R=0.99951) at concentrations as low as 1.75 µg/ml (limit of quantitation) with an average limit of detection of 0.43 µg/ml. PubDate: 2019-05-18 DOI: 10.33687/jfcn.007.01.2843 Issue No:Vol. 7, No. 1 (2019)
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