Retarding vegetable softening by cold alkaline protein deesterification before cooking

Snap beans and carrot tissues, deesterified at 1 degree C and pH 12.5, soften much more slowly than control tissues when cooked at neutral or slightly alkaline pH. High pH or NaCl during cooking had little effect on the degree of softening. Soaking in 0.05 M EDTA led to an 86% loss in firmness. The results were consistent with a reduction in the beta-elimination depolymerization of pectin during heating as a result of deesterification in the alkali. Deesterified tissues remained susceptible to pronounced softening during cooking at pH 3.5. Potatoes, cauliflower apples showed similar effects. Peas gave a reduced response. Beets and dry beans did not show a retardation of softening after an alkali soak