Steam explosion pretreatment to enhance extraction of active ingredients: current progress and future prospects

What if the leftover pomace from your morning juice could become a weapon against diabetes? New research shows that grape and lingonberry waste, when processed with green extraction techniques, yield compounds that inhibit key enzymes linked to blood sugar control.

The agro-industrial sector generates mountains of waste, but within that waste lies a treasure trove of bioactive compounds. This study turned two by-products from fruit processing—lingonberry pomace and grape pomace—into hydroalcoholic extracts using two green methods: ultrasound-assisted extraction and accelerated solvent extraction. Both techniques employ a 50% ethanol solvent at 10% mass, and the resulting extracts were filtered through micro- and ultrafiltration membranes to concentrate the polyphenols.

When tested, the extracts showed significant enzyme inhibition, particularly against α-amylase and β-glucosidase, both of which play roles in carbohydrate digestion and glucose release. The grape pomace extracts were especially potent, with IC50 values nearly identical to acarbose, a standard anti-diabetic drug. For instance, grape pomace achieved an IC50 of 0.30 µg/mL for α-amylase, matching acarbose's 0.3 µg/mL, and 0.60 µg/mL for α-glucosidase, close to acarbose's 0.57 µg/mL.

Statistical comparisons revealed significant differences between the two extraction methods, affecting polyphenolic content, antioxidant capacity, and enzyme inhibition. These findings underscore the potential of agro-industrial residues as low-cost sources of bioactive compounds, contributing to circular economy principles by transforming waste into valuable inputs for food, nutraceutical, or pharmaceutical industries.

Key Points

• Grape pomace extracts match anti-diabetic drug acarbose in enzyme inhibition.
• Green extraction methods (UAE, ASE) recover polyphenols from fruit waste.
• Agro-industrial residues offer circular economy opportunities for health products.