How does oligofructose reduce straight-chain amylose content in parboiled rice?

The ratio of straight-chain starch to branched-chain starch in rice is the main reason that affects the cooking and flavor quality of rice. Studies have shown that the hardness, elasticity and viscosity of rice are closely related to the content of straight-chain starch in rice. Rice with high content of straight-chain starch is hard, while rice with low content of straight-chain starch is softer, moisture-rich and glossy.Li Hongyan et al. showed that straight-chain starch has a significant effect on the hardness of cooked rice. As shown in Figure 2, the proportion of straight-chain starch in rice was significantly reduced (P < 0.05) under 0.8% and 1.6% oligofructose treatments, by 8.50% and 7.36%, respectively, compared with the control. The decrease in the content of straight chain starch may be due to the addition of oligofructose increased the water absorption of the rice, and more straight chain starch was dissolved during soaking and cooking. The low content of straight-chain starch in rice is correspondingly high in palatability. Therefore, the rice obtained after the addition of 0.8% and 1.6% oligofructose treatment had low straight-chain starch content, low hardness and high palatability.