Efficient green extraction of polyphenols from post-harvested agro-industry vegetal sources in Piedmont
Résumé
A study of the polyphenols content and antioxidant capacity of grapevine waste and hazelnut skins (roasted material) from post-harvest products that originate from Piedmont (Italy) has been carried out and the results herein presented. Ultrasound- assisted extraction (UAE) and microwave-assisted extraction (MAE) were used to achieve process intensification in shorter extraction times, with lower environmental impact and higher selectivity compared to classic maceration. Besides classic solvents, the aqueous bcyclodextrin solution (1.5%) showed to be an excellent extraction medium for grapevine waste. Total phenolic content (TP) from grapevine waste ranged from 18.23 [u]+[/u] 2.4 to 198 [u]+[/u] 3 mg gallic acid equivalents (GAE)/g dry weight, while total antioxidant capacity (TAC) expressed as EC50 ranged from 0.0902 [u]+[/u] 0.08 mg/mL to 0.0041 [u]+[/u] 0.02 mg/mL. For hazelnut skins, TP ranged from 61.68 [u]+[/u] 0.8 to 200.79 [u]+[/u] 3.0 mg GAE/g dry weight, while TAC ranged from 0.0021 [u]+[/u] 0.0004 to 0.0002 [u]+[/u] 0.0001 mg/mL extract. We have shown that, compared to maceration, the use of UAE and MAE methods can enhance polyphenols recovery and antioxidant capacity.