Characterize the physicochemical properties and microstructure of pectin from high-pressure and thermal processed cloudy hawthorn (Crataegus pinnatifida) juice based on acid heating extraction

Physicochemical properties and morphological features of pectin in high-pressure-processing (JHPP) and thermal-processing (JTP) treated cloudy hawthorn juice were investigated based on acid heating extraction. Pectin from hawthorn juice was identified as low methoxy pectin (41.77%), which was significantly reduced to 34.56%-39.51% from JHPP, while pectin esterification degree (DE) from JTP increased to 45.58%, which can also be confirmed by Fourier transform infrared spectroscopy. In comparison to control, pectin linearity of JHPP and JTP significantly decreased with more highly branched-chains. However, no significate difference was observed in thermostability, crystallinity and main functional groups. Interestingly, a large number of aggre-gations was observed in JHPP pectin, and the intermodular distance of JTP pectin was enhanced, which was consistent with the results of viscosity, molecular weight and DE. These findings provided insights into utilization of hawthorn pectin and application of high-pressure processing (HPP) for improving quality property of fruit products by pectin modification.

Automated summary

This study investigated the physicochemical properties and morphological features of pectin in high-pressure-processing (JHPP) and thermal-processing (JTP) treated cloudy hawthorn juice using acid heating extraction. It was found that pectin from hawthorn juice was low methoxy pectin (41.77%), which was significantly reduced to 34.56%-39.51% after JHPP treatment, while pectin esterification degree (DE) increased to 45.58% after JTP treatment. The results also showed that the pectin linearity of JHPP and JTP decreased with more highly branched-chains compared to the control. However, there were no significant differences in thermostability, crystallinity, and main functional groups.