Study On The Effect Of Atmosphere Storage On Quality Of Rice

Rice freshly was stored at the constant temperature of 15℃,25℃and 35℃, the concentration of N2 was 90%,95%,100% and the concentration of CO₂ gas was 50%,70%,100%; at the room temperature with atmosphere, 70%CO₂ and 95%N2. The physiological and senses indices were determined routinely to evaluate the effectiveness of atmosphere to the physiology quality of rice during storage. The purpose of this work is to approach the effect of controlled atmosphere storage on quality of rice, and provide theory for application of controlled atmosphere in fresh keeping of rice. The results showed:1.Under room temperature, treated with controlled atmosphere was compared with control have a significant effect, showed that the controlled atmosphere reduced the upgrade rate of water losing, color changing, fatty acid oxidation, starch gelatinization, enzymatic activity, senses indices. The controlled atmosphere had a significant effect on keeping rice quality.2.CO₂ controlled atmosphere had a significant effect, the effect of CO₂ controlled atmosphere storage on inhibiting fatty acid value, the starch setback viscosity and the activity of PPO was better significant then N2, but the effect of N2 controlled atmosphere storage on delaying the peak of starch peak viscosity and breakdown viscosity was better significant then CO₂.3.Under 50-100% CO₂ controlled atmosphere storage and 90-100% N2 controlled atmosphere storage, gas concentrations had a significant effect only for starch breakdown viscosity and the activity of PPO. The high gas concentration had a better effect of delaying the peak of starch breakdown viscosity, and reducing the degrade rate of the activity of PPO.4.Temperature had a significant effect on keeping fatty acid value of rice, compared with 25℃and 35℃, 15℃was the best temperature for fresh keeping of rice.5.The method multiple stepwise regression was used to filtrate the sensitive indexes from the indexes which have significantly correlation or high significantly correlation with storage time and sensory score. The storage quality evaluation formula for rice was Y=109.3269 - 0.0171Xsetback viscosity - 0.7482Xfatty value - 0.0055Xtrough viscosity, setback viscosity, fatty value and trough viscosity were sensitive indexes during the storage, CO₂ controlled atmosphere had a significant effect on inhibiting fatty acid value and starch setback viscosity, so CO₂ controlled atmosphere in fresh keeping of rice had better effect.