Characterization of proteins and phenolic compounds extracted from plant seeds press cakes and potential utilization in wine fining

Abstract

Press cakes, a byproduct of seed processing, are often underutilized despite their rich bioactive composition. This study investigates the potential of proteins and phenolic compounds extracted from press cakes of various plant seeds for application in wine fining. Protein fractions (albumins, globulins, prolamins, and glutenins) were characterized using SDS-PAGE, while phenolic compounds were quantified for total phenolics, tannins, and flavonoids, with antioxidant activity assessed via ABTS and DPPH assays. Sauvignon Blanc and Pinot Noir grape seeds exhibited the highest phenolic and antioxidant activities among the samples. Wine fining trials demonstrated the efficacy of extracted proteins, particularly from hazelnut and flax seeds, in reducing tannin levels in red wines, suggesting their suitability as sustainable alternatives to conventional fining agents. This study underscores the importance of upcycling plant seed press cakes, which are typically treated as waste, into value-added products, aligning with circular economy principles. By exploring sustainable uses for these byproducts, the research aims to address both environmental concerns and the demand for eco-friendly winemaking practices, paving the way for innovative and sustainable wine production methods.