The effect of corn starch and transglutaminase on quality improvement of soybean-based analog rice

The development of soybean-based analog rice is a potential alternative to rice because of its high protein content. However, the soybean-based analog rice has poor physical properties during cooking, so improvements are required. This research aimed to investigate the effects of corn starch and transglutaminase (TGase) additions on the physicochemical properties of soybean-based analog rice. Variation of soybean flour to corn starch ratio (100:0, 80:20, 60:40, and 40:60) and TGase concentrations (0%, 0.5%, and 1%) were applied. The result showed that the soybean-corn starch interaction produced a strong network, decreasing the cooking loss. The addition of corn starch also improved the lightness and whiteness of analog rice. The formulation of 60% soybean and 40% corn starch produced analog rice with a balanced macronutrient composition, providing moderate levels of protein, fat, and carbohydrates, a relatively higher ash content, and the most compact and smoothest microstructure. Furthermore, the addition of TGase increased the texture profile of analog rice, reduced water absorption and volume expansion, and significantly prevented cooking losses. Hence, the combination of soybean flour and corn starch, along with the addition of TGase, improved the physicochemical properties, including the high protein content, color, texture, and cooking quality of analog rice.