Krome Memorial Institute (Tropicals)
Pectin during tree and room ripening of low and high chill, melting and non-melting flesh peach varieties
Abstract
Fruit were sampled to compare pectin in peach [Prunus persica (L.) Batsch] varieties, and to determine if differences exists between low and high chill, melting (mf) and nonmelting (nmf) flesh varieties. Fruit were sampled at 2,1 and 0 weeks before harvest at maximum background color and at 0 up to 9 days of postharvest softening at room temperature (25°C). Soluble pectin levels (CSP + ASP) decreased for all varieties during the last week of on-tree ripening. There were no differences in the chelate soluble pectin (CSP), alkaline soluble pectin (ASP) and residue (RES) fractions for low vs high chill and mf vs nmf classes at the same harvest date. There were no differences in postharvest storage between low vshigh chill or mf vs nmf for grams pectin/100 g mesocarp or /100
g cell walls. However, 'O'Henry' was distinguished from all other peach varieties in postharvest storage with higher grams pectin/100 g mesocarp in the RES fraction; and therefore, a higher TOTAL pectin level indicating an alternate flesh type to mf or nmf.