Grape pomace, the main by-product from winemaking industry, accounts for 20-30% of processed grape weight and still contains valuable compounds. Valorization of pomace by extracting phenols can be a further step towards a “near zero-waste socie-ty” direction. The present work aimed at the selection of the best extraction condi-tions for phenol recovery from Sangiovese and Montepulciano (Vitis vinifera L.) mixed winery pomace. Different solvents were screened in 2h incubation at 30°C and 50°C, with 1:10 and 1:5 solid/liquid ratios, with or without ultrasound pre-treatment. Total phenol yields were measured in all extracts and best extracts were characterized for flavonoid, flavanol and anthocyanin contents and for total antioxidant activity. In conclusion, 75% acetone led to the highest compound extractions, followed by 50% acetonitrile and 50% ethanol. Higher yields were obtained with 1:5 solid/liquid ratio. The ultrasound pre-treatment did not significantly affect compound recovery, while better extractions were achieved with temperature increase.
Winery by-products: pomace as source of high value phenols
Tassoni Annalisa
Writing – Review & Editing
;Ferri MauraWriting – Original Draft Preparation
2019
Abstract
Grape pomace, the main by-product from winemaking industry, accounts for 20-30% of processed grape weight and still contains valuable compounds. Valorization of pomace by extracting phenols can be a further step towards a “near zero-waste socie-ty” direction. The present work aimed at the selection of the best extraction condi-tions for phenol recovery from Sangiovese and Montepulciano (Vitis vinifera L.) mixed winery pomace. Different solvents were screened in 2h incubation at 30°C and 50°C, with 1:10 and 1:5 solid/liquid ratios, with or without ultrasound pre-treatment. Total phenol yields were measured in all extracts and best extracts were characterized for flavonoid, flavanol and anthocyanin contents and for total antioxidant activity. In conclusion, 75% acetone led to the highest compound extractions, followed by 50% acetonitrile and 50% ethanol. Higher yields were obtained with 1:5 solid/liquid ratio. The ultrasound pre-treatment did not significantly affect compound recovery, while better extractions were achieved with temperature increase.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
