Impact of protein content on processing and texture properties of waxy rice flour and glutinous dumpling

Abstract

This study investigated the effect of protein content on the physicochemical and rheological properties of waxy rice flour and textural properties of glutinous dumplings. Mechanical removal of protein content significantly influenced the color parameters and slurry transparency of waxy rice flour, thereby resulting in a brighter and less yellow color with decreased protein content. Swelling power and solubility increased as a result of decreased thiol groups, and weakened starch-protein network interactions, thereby resulting in increasing cooking solid losses and decreasing height to diameter ratios of cooked glutinous dumplings. The pasting properties revealed that the viscosities of the peak, trough, final, and after breakdown values increased with decreasing protein content. Mechanical property determinations using dynamic rheometer and texture analyzers indicated a less elastic gel-like network structure with decreased protein content of waxy rice flour and glutinous dumplings. This study indicated that partial removal of protein from waxy rice flour may lead to potential energy savings and could be helpful in food processes. Among varieties ranked for personal preference by tasters, glutinous dumplings with 3% protein content were the most preferred, with a white and glossy appearance, a less chewy texture, and a sticky feeling in the mouth.