Effects of soaking treatment on water distribution of rice grains, starch characteristics and eating quality of wet rice noodles.

Abstract

Herein, rice was subjected to different soaking processes on water distribution of rice grains, starch characteristics, and eating quality of fresh wet rice noodles. Results demonstrated that, when soaked at temperatures between 10 °C and 40 °C for 120 min, rice grains reached saturation in water absorption, and the hardness gradually stabilized. However, the moisture continued to penetrate the interior of rice grains after 120 min, leading to an increase in moisture content, higher water permeability, and enlarged water migration channels. With extended soaking time periods, the content of damaged starch in rice flour considerably decreased. Although the gelatinization temperature of rice starch decreased after soaking, the enthalpy required for gelatinization increased. The relative crystallinity of rice starch demonstrated an increasing trend, followed by a decreasing trend, and reached its highest value of 18.18 % after 60 min of soaking. To summarize, the texture indices of fresh rice noodles demonstrated an increasing trend, although stretching and cooking quality demonstrated a trend of initially increasing and then decreasing with no considerable changes observed between 120 and 240 min of soaking. In summary, moderate soaking treatment can enhance the edible quality of fresh wet rice noodles.