Recently, Fruit and Vegetable Processing and Nutrition Health Innovation Team of Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences (IFST-CAAS) investigated the effects of osmotic dehydration on the physicochemical and structural properties of pectin of peach chips dried by instant controlled pressure drop (DIC), including monosaccharide composition, molecular structure, functional group changes, thermal stability and rheological properties. The results were published on Food Hydrocolloids (JCR 1, IF=11.0). Dr. Wang Fengzhao is the first author of the paper, and Prof. Bi Jinfeng and Lyu Jian are the co-corresponding authors. The research was supported by China Agriculture (Peach) Research System (CARS-30-5-02) and the Yunnan Science and Technology Talent Project (202305AF150122).

This study focused on the effects of osmotic solute (erythritol, glucose and trehalose) on monosaccharide composition, molecular weight distribution, molecular configuration, microstructure, nanostructure, thermal stability and rheological properties of pectin of DIC dried peach chips. The results showed that osmotic dehydration could inhibit the degradation of HG domain of pectin, and thus exhibited greater molecular weight and better rheological properties. Among them, the molecular weight of pectin in Ery-OD samples was the highest, and the network structure was the loosest. For Glc-OD samples, the degradation of pectin side chain was the most serious, which induced the lowest (8.96±0.11) branching degree of RG-I chain and the widest (1.49±0.01) molar mass distribution. The addition of α-1,1 glucoside bond in trehalose improved the thermal stability of pectin, which contributed to inhibit the degradation of pectin chains and maintain a more complete and compact three-dimensional network structure. Therefore, the molecular weight, number of hydroxyl groups and molecular configuration of the osmotic solutes had significant effects on the molecular weight, structure, thermal stability and rheological properties of pectin, which were the key factors affecting the macro texture of peach chips.

This study would provide a theoretical basis for revealing the effect mechanism of osmotic dehydration on the texture of DIC fruit and vegetable chips at molecular level.

https://doi.org/10.1016/j.foodhyd.2024.110516