Improvement of anthocyanin yield and shelf-life extension of grape pomace by gamma irradiation

This research investigated the effect of gamma irradiation on anthocyanin extraction from grape pomace, and on inhibition of microbial growth and anthocyanin content during subsequent storage. The combination of four variables was investigated: (1) irradiation at doses from 0 to 9 kGy; (2) packaging under vacuum; (3) addition of a low dose of sodium metabisulfite during irradiation; and (4) extraction in the presence of SO2. Results indicate that the irradiation at 6 kGy, packaging in the presence of 0.1% sodium metabisulfite and extraction in the presence of 2000 ppm of SO2 yielded the highest value of anthocyanins, and improved shelf-life of grape pomace. (C) 2000 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.