Insight into the milling degree on the eating quality of rice porridge

Abstract

Milling, as an important step in rice processing, has a critical impact on rice quality. This study aimed to explore the impact of the milling degree (MD) on the eating quality of rice porridge and its relation to the physicochemical properties of rice. As MD increased, there was a decrease in protein and lipid content, while amylose content increased. The change in composition content led to increased taste value, whiteness, and reduced yellowness. Milling facilitated the bound water and immobile water migrated like free water in rice porridge. Consequently, the removal of the rice bran layer improved the water absorption index (WA) and swelling power index (SP) of rice grains during cooking, allowing more starch molecules to leach out. This led to an increase in dry matter (DM), iodine blue value, and the pasting viscosity, resulting in lower hardness and higher stickiness values of rice porridge. Interestingly, when the milling time was 80 s, the overall sensory quality of the rice porridge was better. The findings of this study offer valuable insights into the scientific processing of rice.