Effect of modified atmosphere on polyphenols during storage of pasteurised strawberry purees

The minimum loss of processed fruit nutritional quality must been guaranteed during storage and the atmosphere can be a limiting step. Strawberry purees flushed with gas mixtures: 10 kPa O-2 + 90 kPa N-2, 100 kPa N-2 and air (78 kPa N-2 + 21 kPa O-2 + 0.03 kPa CO2) were stored for 90 days at 4 and 23 degrees C and revealed no effect in total antioxidant activity and in total phenolic content. The compounds (+)-catechin, (-)-epicatechin and quercetin-3-rutinoside were not affected by the atmospheres for both temperatures and ellagic acid was the exception within strawberry phytochemicals, where its concentration was higher for samples stored in air. Total anthocyanin content was better preserved when strawberry pur e was stored in 100 kPa N-2 at 4 and 23 degrees C, at which temperatures their levels decreased 24 and 77%, respectively. At 4 degrees C cyanidin-3-glucoside presented no significant differences between atmospheres. Pelargonidin-3-glucoside and pelargonidin-3-rutinoside decreased both 27% for 100 kPa N-2 and 45% for 10 kPa O-2 and air. All the individual anthocyanins were not affected by the atmospheres when stored at 23 degrees C. (C) 2014 Elsevier Ltd. All rights reserved.