Organic acids as browning inhibitors on harvested ''Baby'' lettuce and endive

The effects of different organic acid solutions on enzymatic browning of ''Baby'' lettuce and ''Geante Maraichiere'' endive were assayed by quantitative measurement of colour changes. Acetic, formic, propionic, malonic, oxalic and lactic acid solutions (10 g l(-1)) were the most effective at preventing discoloration in stem discs taken from the vegetables. Among the above treatments, acetic, propionic, malonic and oxalic acid solutions (50 g l(-1)) were selected and applied with the help of cotton wool to the butt end of lettuce and endive heads. The browning process was evaluated during 7 days of storage at 2 degrees C, plus an additional commercial handling period of 2 days at 13 degrees C. Acetic and propionic acid treatments were the most effective at reducing lettuce-butt discoloration during storage and commercial handling. In general, treatments with organic acid solutions were less effective on endive than on lettuce.