Abstract:In this study, japonica broken rice and taro head powder were used as the main raw materials, supplemented by selenium nutrient, L-α-phosphatidylcholine and monoglyceride as the composite texture regulator. Selenium-rich taro was prepared by extrusion method, through the orthogonal experiment for process optimization, the best technological parameters were obtained: extrusion temperature of 140 ℃, the screw rotation speed of 180 r/min, moisture content of 25% and feed speed of 20 kg/h. Under the optimal processing conditions, the hardness, cohesion, elasticity, gluttony, chewing and loss rate of se-rich taro head reconstituted rice were 401.17 g, 0.75 mJ, 1.63 mm, 396.23 g, 4.05 mJ and 4.12%, respectively. The results were similar to those of japonica rice in texture and loss rate of cooking. The overall quality was better than japonica rice. Selenium-rich taro head recombinant rice had lower crystallinity, amylose - lipid complex, and the improved rough surface, irregular shape, incomplete particles, reduced viscosity, thermal stability and aging resistance. The contents of fast digestible starch, slow digestible starch and resistant starch in recombinant rice of se-rich taro head were decreased, and the contents of resistant starch and slowly digestible starch were increased. Starch and resistant starch in the recombinant rice of se-rich taro head were decreased, and the contents of resistant starch and slowly digestible starch were increased by extrusion. The results provide basis for developing starch food with low digestibility containing se and taro products.
