Table of Contents
Influence of winemaking by-products on the phenolic activity of beer
Natia Bilanishvili and Levan Gulua
This research explores a novel approach in beer production by incorporating waste materials such as grape seeds and skins, derived from wine processing, into the brewing process. This initiative holds promise for effective waste utilization, advancing craft beer, and utilizing cost-effective raw materials. Experiments explore the integration of grape by-products into beer production, evaluating their impact on polyphenol levels and sensory characteristics. The laboratory and pilot brewhouse trial results revealed a significant increase in the total polyphenol content when 0.6 % grape seeds were added during the boiling process. Specifically, the total polyphenol value doubled, reaching up to 500 mg/l compared to the 250 mg/l found in classical pilsner-type beer. The study indicates that grape seed addition is significantly more effective than grape skin addition under the same conditions, yielding around 1.5 times or more polyphenols. Sensory evaluations revealed a preference for beers supplemented with white grape seeds compared to red grape seeds, providing a unique taste experience with a pleasant grape aroma. Moreover, beers with grape seed additions exhibited elevated levels of specific polyphenolic compounds, particularly catechin and epicatechin. Additionally, the antioxidant capacity of the beer slightly increased with grape seed incorporation and colloidal stability was not negatively affected.
Descriptors: polyphenols, grape seed, value-added beer, epicatechin, grape skin
BrewingScience, 77 (May/June 2024), pp. 50-56
