Changes in Phenolic Compounds During Storage of Pasteurized Strawberry

This study aimed to establish mathematical models to describe changes in phenolics of pasteurized strawberry (Fragaria x ananassa Duch.) during storage at 23 A degrees C for 90 days. Freshly cut strawberries cubes were pasteurized for 5 min in a water bath at 90 A degrees C following a heating time of 15 min. Antioxidant activity, total phenolics, total anthocyanins, and individual phenolic compounds were assessed immediately before or after pasteurization and at regular time intervals during storage. The results indicated that (1) pasteurization did not affect (P < 0.05) the concentrations of total phenolics or total anthocyanins, but significantly reduced the concentrations of quercetin-3-rutinoside, kaempferol, and cyanidin-3-glucoside, and increased the concentrations of (+)-catechin, (-)-epicatechin, epigallocatechin gallate, quercetin-3-galactoside, and ellagic acid; (2) changes in antioxidant capacity, total anthocyanin, and individual compounds during storage were described by a pseudo-first-order model with the exception of total phenolic and specifically kaempferol and ellagic acid which followed zero-order kinetic models. Pelargonidin-3-glucoside degraded at the highest rate (k = 0.07 day(-1)), followed by ellagic acid (k = 0.004 day(-1)) and kaempferol (k = 0.003 day(-1)). The rate constants can be used to predict phytochemical changes in strawberry products during storage.