Effect of Protein Content and Extrusion Process on Sensory and Physical Properties of Extruded High-Protein, Glutinous Rice-Based Snack

Abstract

Development of high-protein glutinous rice-based snacks containing glutinous rice flour, soybean meal and vital wheat gluten was produced using a twin-screw extrusion process. A factorial design was employed to investigate the influence of feed protein content (20 and 30%), feed moisture (20%, 25%, and 30%) and barrel temperature (150 and 180°C) on the sensory and physical properties of extrudates. Descriptive analysis results showed that increasing of protein content significantly increased hardness, noise, and crispness intensity but less sticky mouth feel coating. Increasing feed moisture content resulted in increased final extrudate hardness, noise, crispness and brittleness but reduced sticky mouth coating and colour. Extrusion under high barrel temperature (180°C) reduced intensity of all sensory attributes except colour. For the colour parameters, the increasing of protein content or barrel temperature, or decreasing of feed moisture resulted in decreasing of L*, while a* and b* values were increased. The increase in protein and moisture content and decrease in barrel temperature resulting in increased breaking strength index.