Improvement of polysaccharide extraction from white grape pomace by-products using green thermal techniques

Wine waste is a massive problem—but what if it holds the key to valuable bioactive compounds? New research shows that green thermal techniques can unlock polysaccharides from grape pomace with higher yield and purity.

The wine industry produces mountains of organic waste, with grape pomace accounting for up to 60% of solid by-products. Instead of letting this go to waste, scientists are turning it into a treasure trove of bioactive compounds, particularly polysaccharides (PS). This study compared three extraction methods: accelerated solvent extraction, microwave-assisted extraction, and a conventional heat method, all applied to white grape pomace.

Temperature and technique emerged as the main influencers of extract composition. Lower temperatures favored oligosaccharides, while higher temperatures pushed out non-pectic polysaccharides, mainly cellulose, with high molecular weight. Notably, microwave and conventional thermal methods boosted PS yield and purity while cutting extraction time.

All extracts showed a low degree of esterification, pointing to polar polysaccharides. The study underscores the power of green techniques to recover structurally diverse PS from grape by-products, with promising implications for the food industry.

Key Points

• Green techniques boost polysaccharide yield and purity from grape pomace.
• Temperature controls extract composition: low for oligosaccharides, high for cellulose.
• Microwave and thermal methods cut extraction time effectively.