Effect of grape (Vitis vinifera L. cv. Pinotage) pomace supplementation on nutrient utilization in finisher lambs

Meat quality, metabolic profile and antioxidant status of lambs fed on seedless grape pomace (Vitis vinifera L.)

This study was aiming to research the effect of the seedless grape pomace (GP) added to feed mixture on meat quality, metabolic profile, and antioxidant status of Merinolandschaf lambs. The 90 days old lambs in the control group (C, n=10) were fed feed mixture without GP while in experimental groups were fed with 10% (GP10, n=10) or 20% (GP20, n=10) of GP in feed mixture for 30 days. There was a significant increase in L*, a* values and hue angle as well as a decrease in b* values of lamb carcasses in GP10 and GP20 compared to C group. When lambs were fed GP glucose concentrations decreased, while non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) increased on the 30th day in GP10 and GP20 compared with C group. A significant increase in SOD activity on day 30 and GPx activity on day 15 in lambs’ blood of GP10 and GP20 compared with C group was determined. Also, an increase in DPPH in lamb GP10 and GP20 compared with C was determined. The obtained results of the meat quality, metabolic profile and antioxidant status parameters of lamb meat showed that the use of 10% GP in the diet is justified, while 20% of GP was questionable.

Extraction of the antioxidant phytocomplex from wine-making by-products and sustainable loading in phospholipid vesicles specifically tailored for skin protection

The present study is aimed at valorizing grape pomace, one of the most abundant winery-making by-products of the Mediterranean area, through the extraction of the main bioactive compounds from the skin of grape pomace and using them to manufacture innovative nanoformulations capable of both avoiding skin damages and promoting skincare. The phytochemicals were recovered through maceration in hydroethanolic solution. Catechin, quercetin, fisetin and gallic acid, which are known for their antioxidant power, were detected as the main compounds of the extract. Liposomes and phospholipid vesicles modified with glycerol or Montanov 82® or a combination of both, were used as carriers for the extract. The vesicles were small (~183 nm), slightly polydispersed (PI ≥ 0.28), and highly negatively charged (~-50 mV). The extract was loaded in high amounts in all vesicles (~100%) irrespective of their composition. The antioxidant activity of the extract, measured by using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) test, was 84 ± 1%, and slightly increased when loaded into the vesicles (~89%, P < 0.05). The grape pomace extract loaded vesicles were highly biocompatible and able to protect fibroblasts (3T3) from the oxidative stress induced by hydrogen peroxide.