Comparison of Antibacterial and Antioxidant Properties of Red (cv. Negramaro) and White (cv. Fiano) Skin Pomace Extracts

Abstract

Wine pomace has attracted the attention of the food industry, due to its high content in bioactive compounds, and its multiple healthy activities. In this work, whole and separated skin pomaces from fermented (red) and un-fermented (white) grape by-products were characterized for their antioxidant and antimicrobial activities in order to exploit them as functional food ingredient. Antioxidant activity, measured by both ORAC and TEAC assays, was higher in whole than in skin pomace extracts. The characterization of phenolic composition in whole and skin pomace extracts confirmed the peculiarity of some compounds such as anthocyanins (107.84 + 10.3 mg/g TP) in red skin pomace and a great amount of flavanols (80.73 + 4.04 mg/g TP) in white skin pomace. Whole and skin pomace extracts displayed the same antibacterial activity at 250 µg gallic acid equivalents (GAE)/mL. Red and white skin pomace extracts showed a Minimum Inhibitory Concentration (MIC) of 31.25–62.5 GAE/mL against Staphylococcus aureus and Enterococcus faecalis. Pseudomonas spp. were more sensitive to red skin pomace extracts rather than white skin pomace extracts. Given these results, both red and white pomace extracts could be exploited for future application in food, pharmaceutical and cosmetic industry.

Anthocyanins Found in Pinot Noir Waste Induce Target Genes Related to the Nrf2 Signalling in Endothelial Cells

“…This study evaluates the antioxidant capacity through the Oxygen Radical Absorption Capacity (ORAC). Lately, the ORAC value has been used to standardize the antioxidant activity of herbal and food extracts, widely used as an objective indicator of antioxidant activity in vivo [ 47 ]. The ORAC method measures the ability of phytochemicals to neutralize peroxyl radicals [ 48 ], since the ORAC antioxidant capacity of the extracts will increase proportionally with their anthocyanin content [ 49 ].…”

“…The results of this research are consistent with the data, showing that the ORAC of the extract generated from the total pomace of the Negramaro strain (2496.75 ± 449.20 µmol TE/g d.w.) is higher than the ORAC generated from the skin extract (1767.85). ± 126.96 µmol TE/g d.w.) [ 47 ]. Chitosan-encapsulated grape pomace nanoparticles increased their ORAC from 2058 to 2463 μmol TE/g after digestion [ 50 ].…”

Grape Pomace Extract Attenuates Inflammatory Response in Intestinal Epithelial and Endothelial Cells: Potential Health-Promoting Properties in Bowel Inflammation

“…Grapes are one of the largest fruit crops in the world, and almost all of the production (about 80% of the yield) is used for wine making. Due to the wide availability of grape skins, the utilization of grape by-products has attracted increasing attention for their potential health benefits not only for their antioxidant activity, but also for their antibacterial, anti-inflammatory, and anticarcinogenic properties [ 18 , 19 ]. These biological properties are believed to be due to the functions of polyphenols and dietary fibers still contained in grape pomace after grape fermentation.…”

“…These biological properties are believed to be due to the functions of polyphenols and dietary fibers still contained in grape pomace after grape fermentation. Among grape pomace compounds with high nutraceutical value [ 20 , 21 ], polyphenols such as phenolic acids, flavanols, proanthocyanidins, flavonols, anthocyanins, and stilbenes are the most interesting due to their antioxidant, anti-inflammatory, anti-neurodegenerative, anti-microbial, anti-cancer, and cardioprotective activities [ 19 , 22 ]. For these reasons, grape pomace could be exploited as a natural source of functional polyphenolic compounds for food or pharmacology use [ 21 , 23 , 24 ].…”

“…These dietary polyphenols were able to attenuate endothelial dysfunction and reduce leukocyte adhesion to the endothelium [ 26 , 27 ]. Moreover, recent evidence reports grape pomace to improve the gut microbiota by increasing the beneficial bacteria and decreasing the harmful bacteria, as well as reducing the level of pro-inflammatory cytokines [ 19 , 28 ]. However, the biological health potential of grape pomace-derived polyphenols on intestinal and vascular inflammation and the underlying mechanisms of action are not entirely clear.…”