Effects of enzyme treatment on powdery properties of coarse cereals-indica rice flour and quality of their fresh rice noodles

The coarse cereals contain rich nutrients. Adding some coarse cereals to rice noodles with rice as the main raw material can effectively improve people's diet structure, while the addition of enzymes can further help the release of nutrients in coarse cereals, thus improving the digestion and absorption of nutrients. To explore the effects of enzyme treatment on the quality characteristics of rice noodles of black rice, buckwheat, and barley, and to provide a theoretical basis for the diversification and nutrition of the development of fresh rice noodles. These coarse grains treated with α-amylase and cellulase (added at a mass fraction of 0.05%) were mixed with indica rice at a ratio of 1∶4, then the pasting, rheological and textural properties of these grains and indica rice were tested to explore the effects of enzymatically hydrolyzed coarse cereals on the powder characteristics of indica rice flours and on the quality characteristics of fresh rice noodles. As shown by the experimental results, compared with the untreated grain-indica rice groups, the water solubility, swelling power and viscosity of the starch of enzymatic treated groups, the turbidity of the cooking water of rice noodles, inlet fineness and dietary fiber content increased. To be specific, the contents of dietary fiber of the enzymatically hydrolyzed black-indica rice, buckwheat-indica rice, and barley-indica rice were increased by 12.21%, 47.49%, and 51.48%, respectively. The starch paste viscosity, breakdown, setback, and the hardness and chewiness of rice noodles were reduced. The comprehensive analysis showed that a significant effect was observed on the indica rice flours and their rice noodles quality through addition of the three kinds of coarse cereals treated with enzymatic hydrolysis. The starch pasting characteristics, rheological characteristics and gel textural characteristics of the enzymatically hydrolyzed buckwheat-indica rice were the best compared with the other two kinds of enzymatically hydrolyzed grains; the textural, cooking and sensory quality of its rice noodles were much closer to pure indica rice noodles and the contents of dietary fiber reached the highest value within the test groups (9.96 g/100 g). The results can provide scientific guidance for the development of the enzymatically hydrolyzed buckwheat rice noodles.