Textural Changes of Yellow Peach in Pouches Processed by High Hydrostatic Pressure and Thermal Processing During Storage

Abstract

Textural changes of yellow peach in pouches (YPP) treated by high hydrostatic pressure (HHP) and thermal processing during storage at 4 ± 1 °C and 25 ± 1 °C for 180 days were studied. Hardness, syrup viscosity, pectin compositions, and cell structure of YPP samples were evaluated in this study. The hardness of YPP stored at 4 ± 1 °C exceeded 50–70 % as compared to those stored at 25 ± 1 °C. Moreover, the higher flesh hardness and lower syrup viscosity were obtained at longer pressure-holding time of HHP processing. Water-soluble pectin (WSP), sodium carbonate-soluble pectin (NSP), and total pectin contents in flesh decreased, while chelate-soluble pectin (CSP) in flesh and water-soluble pectin in syrup (WSPS) increased after 180 days storage. The texture degradation in YPP was mainly caused by solubilization and depolymerization of WSP and NSP. The temperature of 4 ± 1 °C inhibited pectin degradation and delayed the softening of flesh and the increase of syrup viscosity more effectively than 25 ± 1 °C. Comparing with the flesh tissue microstructure of HHP-processed YPP stored at 25 ± 1 °C, better cell structures of YPP were retained during storage at 4 ± 1 °C. Since the breakdown of intercellular cementing pectin was obviously delayed at lower storage temperature, thus cell wall loosening and distortion were prevented.