Changes in Pectin Composition and Structure During Thermomechanical Treatment and Their Intrinsic Relationship with the Quality of Purple Sweet Potato Puree

In order to design texture-modified foods suitable for the elderly people with dysphagia, the effect of thermomechanical treatment on the texture of purple sweet potato puree (PSPP) requires further investigation. This research conducted a systematic combination of heat treatment time and mechanical treatment (stirring rate and stirring time) on the texture properties of PSPP. The results showed that the hardness and cohesiveness of PSPP met the requirements of "Foods for People with dysphagia" when heat treatment time was 55 min, stirring rate was 1000 rpm, and stirring time was 25 min. After thermomechanical treatment, the pectin of PSPP was degraded via β-elimination and the structure was changed. PCA and Pearson correlation analysis proved that ideal textural and rheological properties were related to the structure of the pectin side chain (Gal/Ara). This study provides great significance for further designing PSPP with targeted texture properties and developing special food for the elderly with dysphagia.