Effects of the Mixing Ratio of Purple Rice and Indica Rice on the Properties of Mixed Powder and the Quality of Purple Rice Noodles

In this paper, the properties of purple rice powder were improved by mixing high amylose indica rice powder, and the effect of different proportions of mixed powder on the properties of raw materials and the quality of purple rice noodles was studied. The purple rice powder and the indica rice powder were mixed according to a certain proportion to make noodles. The physicochemical properties of mixed powder including amylose content, solubility, swelling power, gel consistency, gelatinization and gel properties were used as determination indexes. And the cooking, anthocyanin content and retention rate and sensory quality of purple rice noodles were used as evaluation indicators. The results showed that the optimum proportion of raw material powder was indica rice powder: purple rice powder=8:2. Under this ratio, the amylose content of the mixed powder increased from 15.75 g/100 g of pure purple rice powder to 26.86 g/100 g, the solubility decreased to 6.24 g/100 g, the swelling force decreased to 6.80 g/g, and the gel consistency decreased from the medium-soft consistency to hard consistency, the trough viscosity, final viscosity and retrogradation value increased, the gel hardness and water holding capacity increased, and the adhesiveness and weight loss rate decreased. The above-mentioned changes in the properties of the raw materials enhanced the structural strength of the purple rice noodles gel, reduced its stickiness, optimized its hydration properties, and finally improved the quality of the purple rice noodles. The quality of purple rice noodles made under the optimum ratio was as follows: The cooking time was 508 s, the broken strip rate was 9.67%, the cooking loss rate was 34.37%, the cooking quality was similar to the commercial rice noodles, the anthocyanin content was 18.36 mg/100 g, the retention rate reached 65.68%, and the color was purple, with the fragrance of purple rice, moderate hardness and softness.