Abstract: In order to explore the effect of syrup properties on the texture of canned yellow peach (cv. ‘Goldbaby 5’), changes in the syrup characteristics including pH, total soluble solid (TSS) content, turbidity, color, apparent viscosity, osmotic pressure, and water soluble pectin in syrup (SWSP) content were measured during storage. Scanning electron microscope (SEM) and light microscope (LM) were applied to observe the microstructure of the fruit flesh. At the same storage times syrup samples from different locations (the upper, middle and lower layers) did not show a significant difference in pH or TSS content, illustrating that the mass transfer between the syrup and the flesh cells was uniform. The syrup pH did not change obviously with storage time. On the other hand, the syrup presented a decrease in TSS content, L* value and a* value, and an increase in turbidity, b* value, osmotic pressure, SWSP content. These parameters tended to stable at the late stage of storage. Deformation or even collapse of the flesh cells was observed by SEM and LM, macroscopically manifested by flesh softening, namely a significant decrease in hardness and chewiness (P < 0.05). A significant negative correlation between texture properties (hardness, resilience, cohesiveness and chewiness) and b* value, turbidity, osmotic pressure and SWSP content was found (P < 0.05) as well as a significant positive correlation of hardness and chewiness with L* value and a* value (P < 0.05). From these findings, it was clear that the texture of canned yellow peaches could be significantly affected by the syrup properties during storage and consequently could be improved by regulating them.

Key words: canned yellow peach; storage; syrup characteristics; texture; osmotic pressure