12.
Polyphenol, antioxidant and antimicrobial potential of six different white and red wine grape processing leftovers : /Kajetan Trošt,
Anja Klančnik,
Branka Mozetič Vodopivec,
Melita Sternad Lemut,
Katja Jug,
Peter Raspor,
Sonja Smole Možina, 2016, original scientific article
Abstract: BACKGROUND
During winemaking, grape polyphenols are only partly extracted, and consequently unexploited. The main aim was to characterise the phenolic content of freeze-dried grape skin and seed (FDSS) extracts obtained from Slovenian and international grape varieties and evaluate their antioxidant, antimicrobial, and anti-adhesive activities.
RESULTS
FDSS of six Vitis vinifera L. grapevine cultivars from Vipava Valley region (Slovenia) underwent extraction and sonification under different conditions. Flavonols were the predominant content of extracts from white ‘Zelen’ and ‘Sauvignon Blanc’ grape varieties, with strong antimicrobial activities against Gram-negative bacteria. ‘Pinot Noir’ FDSS extracted with 50% aqueous ethanol extraction produced a high phenolic content in the final extract, which was further associated with strong antioxidant and antimicrobial activities against all tested bacteria. Bacterial adhesion to stainless steel surfaces with minimal and maximal surface roughness was significantly inhibited (up to 60%) across a wide FDSS concentration range, with lower concentrations also effective with two types of stainless steel surfaces.
CONCLUSION
FDSS extracts from winery by-products show interesting phenolic profiles that include flavonols, catechins, anthocyanins, and hydroxycinnamic acids, with yields influenced by grapevine cultivar and extraction conditions. The antioxidant, antimicrobial and anti-adhesive activities of 50% aqueous ethanol ‘Pinot Noir’ FDSS extract reveals potential applications in food, pharmaceutical and cosmetic industries for these bioactive residues.
Keywords: grape skins and seeds, extraction solvents, phenolic profile, antioxidant activity, antimicrobial activity, anti-adhesion activity to stainless steel
Published in RUNG: 08.08.2016; Views: 5074; Downloads: 0
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