The Storage Quality Indicators Changes Of Rice After Controlled Atmosphere Storage

In order to explore the changes of rice storage quality in different environments afterlifting the CA storage, through two kinds of the Simulation Environment35°C,80%RH,30°C,70%RH and room temperature storage experimental, the appearance characteristics,physicaland chemical indexes, cooking texture properties, starch microstructure, the total number offungal colonies and the pests of rice were determined. The correlations and differences amongthese indexes and with the storage time or storage temperate were studied, the most sensitiveindex was selected and set up an aging mathematical model, the result are:（1）The rice surface is smooth and no bran powder after six months storage at roomtemperature, but the gloss decreases gradually, the whole appearance quality is significantlybetter than the other two storage conditions. the rice under35°C,80%RH and30°C,70%RHconditions with serious bran causing, loss of gloss and color, the appearance quality inferior toroom temperature storage conditions. Two rice samples in the process of storage at roomtemperature no obvious changes of smell, the CO₂samples in the35°C storage for100days,30°C for150days storage the smell were not normal. Vacuum sample at35°C hightemperature storage for150days storage,30°C for175days storage appear abnormal odor. L*number, a*number decreased, b*number increased for175days storage. The initial a*number of CO₂samples showed a downward trend, b*number of vacuum sample storageconditions were significantly increased, under35°C conditions b*number increased from theinitial1to5.8for175days storage, yellow chroma increased significantly. In roomtemperature storage conditions b*number increased from the initial1to4.7, showed that thehigh temperature and humidity influenced the stored rice surface clearly.（2）Cooking quality change of the two rice samples are basically the same, the waterabsorption of rice increased, the pH,iodine blue value and solids of rice soup decreased indifferent storage environments with the extension of storage time, and the high temperatureenvironment changed above room temperature storage. Two rice samples of rice texture resultshowed that rice hardness, plastic viscosity showed an increasing trend with storage time,flexibility, adhesion and cohesive of the rice decreased with the extension of storage time, theCO₂and vacuum rice samples chewing were inconsistent with time trend, the stalemate withstorage time of two rice samples showed an upward trend, the chewiness of CO₂atmosphererice showed an increasing trend for175days storage, while the chewiness of vacuum riceincreased first and then decreased. Two rice hardness, plastic viscosity, water absorption and chewiness was significantly related with storage time, the rice soup dry matter, pH, iodine bluevalue, flexibility, cohesion, adhesion, sensory scores were very significant negativerelated withstorage time, the sensory score with solids of rice soup, iodine blue value, pH, cohesion,chewiness and adhesiveness highly significant positive correlation of CO₂samples, the sensoryscore was a significant negative correlation with water absorption, hardness and plasticviscosity. The palatability of two rice samples in each storage conditions decreased for175days storage, the35°C,80%RH and30°C,70%RH conditions changed rapidly.（3）With the extension of storage time the ED, FAV and the activity of microbial increased,MDA, PPO, POD decreased. The rice quality indicators changed slowly at room temperaturestorage experimental, the rice quality indicators changed rapidly after opening at35°C,80%RH and30°C,70%RH for175days storage. The FAV, ED, microbial activity with ricemoisture were very significant positive correlation, with the falling number, reducing sugarwas significantly negatively correlated, and POD was not significantly correlated with ricemoisture. Reducing sugar, falling number, fatty acid value, microbial activity and ED showed asignificant correlation with the storage time, the highest correlation coefficient with storagetime was ED, the CO₂sample was0.858, vacuum sample was0.954. PPO and POD withstorage time extremely relevant. POD and fatty acid value was highly significant negativecorrelation.（4）The CO₂storage quality evaluation formula was Y=123.97-55.35XL*-0.96X脂肪酸值+7.29X丙二醛, for vacuum rice was Y=140.22-0.96X脂肪酸值-0.09X降落数值. Validated test showed bothformulas were feasible.