HYPOCHLORITE INHIBITION OF ENZYMIC BROWNING OF CUT VEGETABLES AND FRUIT

Oxidative browning of injured plant tissues mediated by the enzyme polyphenoloxidase is a limiting factor in the handling of many fresh cut vegetables and fruit.
Sodium and calcium hypochlorite solutions of 1–5 ppm at pH 7 are used in minimal processing operations for sanitation.
Hypochlorous acid is the predominant antimicrobial species at pH 7. We have used basic solutions at higher concentrations to inhibit oxidative browning in green beans, apples and potatoes; banana tissue was injured by hypochlorite.
Apple and potato tissue was sliced into solutions of sodium or calcium hypochlorite at concentrations from 17.5 to 140 ppm and pH 4, 7, or 11 for immersion times of 5, 10, or 20 minutes.
Browning was measured at 5 minute intervals for 1 hour at room temperature (22–25C) and again after 5 hours at 5–7C as the change in L value using a Hunter ColorQuest reflectance colorimeter.
Our results indicate that 17.5 ppm hypochlorite inhibits browning and that higher concentrations are potentially as effective as ascorbate and bisulfite treatments.

Physiological Basis of Postharvest Technologies

J.K. Brecht, A.U.O. Sabaa-Srur, S.A. Sargent, R.J. Bender

https://doi.org/10.17660/ActaHortic.1993.343.83