Prevention of browning of banana slices using natural products and their derivatives

Fresh-cut banana slices were treated with pineapple juice, neutral sugars, isoascorbic acid, citric acid, other organic acids, N-acetylcysteine, 4-hexylresorcinol and mixtures of these compounds and evaluated for browning reaction. A number of other compounds previously reported to be antibrowning agents were also tested. Preliminary tests revealed that many purported antibrowning agents, including pineapple juice, had only transitory or no effects on browning of banana slices. Subsequent replicated treatments of slices stored at 5C and 15C for 7 days showed that of the several treatments, those using citric acid and N-acetylcysteine were highly effective at reducing browning. Reflectance measurements taken immediately after treatment, after 2 days of storage, and at the end of the I week storage period confirmed that a mixture of 0.5 M citric acid and 0.05 M N-acetylcysteine provided the best protection against browning at both temperatures. No microbial decay was observed during the 7 day period studied.