Biotechnological Methods of Upcycling Grape Pomace for Food Use─A Review

Grape pomace (GP), the major waste product of wine production, accounts for over 3.4 million tons annually and contains valuable bioactive chemicals. As sustainability becomes increasingly important, GP remains an underutilized resource with significant potential for the food industry. This review aims to discuss key barriers for upcycling GP, current extraction and fermentation methods, potential applications in food, and future perspectives. Among the approaches of chemical, physical, and biotechnological extraction processes, biotechnology such as enzyme-assisted extraction and fermentation can not only extract existing compounds from GP but also transform GP into other valuable compounds. However, there continues to be a large gap between literature and industry as cost-effective production methods for high value products have yet to perform at large scales. Fermentation is promising due to its potential to generate natural bioactive metabolites, ingredients, and foods, aligning with clean-label consumer trends. Thus, GP represents a valuable opportunity for sustainable innovation in food applications.