Grape pomace is one of the main by-products in the wine industry and contains some high-added-value compounds, such as polysaccharides. Considering the wide application possibilities of polysaccharides in wine and in the food industry, the revalorization of grape pomace to extract polysaccharides presents itself as an opportunity for by-product management. Therefore, the aim of this study was to characterize polysaccharide extracts obtained from pomace by-products of different white grape varieties. The type and content of polysaccharides, proteins and phenols were analyzed. Statistically significant differences were found between the varietal extracts in the types and concentrations of polysaccharides. The extracts obtained from the Verdejo and Puesta en Cruz varieties showed the highest polysaccharide purity and contents, but the type of polysaccharides was different in each case. The Verdejo provided extracts richer in non-pectic polysaccharides, while the Puesta en Cruz provided extracts richer in pectic polysaccharides. The protein and polyphenol contents were low in all extracts, below 2.5% and 3.7%, respectively. These results open up a new possibility for the revalorization of grape pomace by-products to obtain polysaccharide-rich extracts, although it would be interesting to improve both the yield and the purity of the extracts obtained by studying other extraction techniques or processes.
The aim of this work was to evaluate the effect of an olive extract (OE) on the physicochemical and microbiological characteristics, lipid oxidation and volatile compounds of beef patties stored both aerobically and under modified atmosphere packaging for 15 days at 4 °C. The antioxidant and antimicrobial effects of the OE were compared to those of sulfite. Four formulations were elaborated according to the antioxidant and dose used: without antioxidant, C; 300 mg potassium metabisulfite/kg product, S; 150 mg OE/kg product, OE1; and 250 mg of OE/kg product, OE2. The parameters analyzed were pH, water activity, color, lipid oxidation (TBARS and volatile organic compounds: hexanal, 2-pentyl-furan, 1-pentanol, 2,3-octanedione and nonanal, 1-octen-2-ol) and total viable counts. The OE delayed the loss of the bright red color of the patties and reduced the lipid oxidation in both types of packaging compared to the control patty. Sulfite was the most effective antioxidant for inhibition of the total viable counts. An OE could be used as a natural antioxidant to delay the lipid oxidation of meat without negatively affecting its physicochemical properties.
16 August 2023 in Journal of Agricultural and Food Chemistry
Grape pomace is one of the main by-products in the wine industry and contains some high added-value compounds such as polysaccharides. Considering the wide application possibilities of polysaccharides in wine and in the food industry, the revalorization of grape pomace to extract polysaccharides presents itself as an opportunity for by-product management. Therefore, the aim of this study was to characterize polysaccharide extracts obtained from pomace by-products of different white grape varieties. The type and content of polysaccharides, proteins and phenols were analyzed. Statistically significant differences were found between the varietal extracts in the types and concentrations of polysaccharides. The extracts obtained from the Verdejo and Puesta en Cruz varieties showed the highest polysaccharide purity and contents, but the type of polysaccharides was different in each case. The Verdejo provided extracts richer in non pectic polysaccharides, while the Puesta en Cruz in pectic polysaccharides. Protein and polyphenol contents were low in all extracts, below 2.5% and 3.7%, respectively. These results open up a new possibility for the revalorization of grape pomace by-products to obtain polysaccharide-rich extracts, although it would be interesting to improve both the yield and the purity of the extracts obtained by studying other extraction techniques or processes.
Grape polysaccharide extracts derived from winemaking by-products have been shown to affect key wine characteristics. This study aimed to investigate the application of different grape-derived, polysaccharide-rich extracts and commercial yeast products in white sparkling wines, since no other studies have been found. The impacts of these products on the volatile, phenolic and polysaccharide compositions, as well as on the foam properties and sensory characteristics, were evaluated. After 15 months of aging, the products used did not influence the color and phenolic composition of the sparkling wines. However, they had a positive effect on the volatile compounds, with treated wines showing a general increase compared with the control, mainly in ethyl esters and alcohol acetates, compounds associated with fruity and floral notes. The treated wines showed clear sensory differences compared with the control, including aromatic complexity, which may reflect better preservation of certain aromatic compounds over time. In addition, improvements in wine taste were observed, likely due to a reduction in perceived acidity and bitterness. These results demonstrate the potential of grape-derived polysaccharide extracts to preserve volatile compounds in sparkling wines and to enhance their aromatic complexity and mouthfeel, thus improving overall sensory quality.
Volatile compounds contribute to wine aroma and can interact with polyphenols, polysaccharides (PS), and proteins. This work evaluated the effects of adding different PS extracts obtained from winery by-products, must and wine on the volatile composition and sensory attributes of young red wines. These results highlight the effect of the wine matrix on the impact of PS on the volatile composition. The highest concentrations of volatile compounds were reached in wines with higher phenolic content and mainly those treated with PS extracts contained higher proportions of low-molecular-weight PS (55–68%). These PS extracts maintained high concentrations of compounds related to fruity and floral aromas, such as ethyl esters of fatty acids (8–23%), alcohol acetates (9–23%), and terpenes (11–43%). In addition, the PS extracts from winery by-products and wines improved taste sensations in young red wines, mainly those with high acidity, by reducing acidity, bitterness and astringency. Therefore, PS extracts obtained from by-products have the capacity to modulate the volatile composition and mouthfeel of red wines with high phenolic content, excess acidity or astringency.