Screening of various anti-browning agents for apple slices

Surface browning, caused by cutting and other wounds during minimal processing, is anvery important quality criterion to consumers. This study was carried out to develop natural anti-browning agents for fruits and vegetables. Taraxacum platycarpum, Chrysanthemum morifolium, onion, cysteine, ascorbic acid, citric acid, NaCl and sucrose were used as anti-browning agents. Taraxacum platycarpum, Chrysanthemum morifolium, and onion were extracted three times with distilled water and 80% EtOH at 60°C for 6 h. Apples were purchased from a local market in Seoul, Korea. The apples were cut into 3-mm thick slices with a sharp stainless knife. The prepared, peeled apple slices were dipped in the various anti-browning treatment solutions (1, 5, 10, 20% extractions of Taraxacum platycarpum, Chrysanthemum morifolium, onion; 0.5, 1, 3, 5% ascorbic acid, citric acid, cysteine; and 0.9% sucrose and NaCl) for 1 min. The 10 and 20% extractions of Taraxacum platycarpum, Chrysanthemum morifolium, and onion were effective in reducing browning of apple slices. The appearance of sliced apples dipped in 3 or 5% cysteine were better than dipped in other agents, however the was a strong off-odor. The compounds 1% ascorbic acid, 5% citric acid or 0.9% NaCl delayed browning of apple slices. These agents could be expected to inhibit browning and extend the shelf-life of fruits and vegetables.