Study On Quality Change Of High Quality Indica Rice Under Different Storage Condition

In this experiment, high quality indica Feng You22and common indica werechosen as the research objects, which stored360days under different temperatures(15℃,20℃,25℃,30℃) and moisture content (13.5%,14.5%,15.5%). And theindexes of water, yellow-colored rice, amylose content, iodine blue value, fatty acidvalue, alpha-amylase activity, germination percentage, gel consistency,conductivity, starch gelatinization properties and protein content were deterimintedregularly. The change rule of quality parameters to high qualit indica in storageprocess was studied through objective scoring to the taste value of rice grain andrice, then compared to the change of quality parameters to common indica in thesame storage condition. The endosperm construction of both fresh and antiquatedindica were observed by scanning electron microscope (SEM). Meanwhile, thecorrelatin of taste value and quality indexes to indica were analysed. The mainresults are as follows:(1) With the lengthening of storage time, the yellow-colored rice rate, amylosecontent, fatty acid value, gel consistency and conductivity of high quality indicawent up. Instead, the iodine blue value, alpha-amylase activity, germinationpercentage, protein content and taste value went down. And the starchgelatinization properties showed significant changes. Besides, the peak viscidity,hot paste viscosity, cold paste viscosity, setback and revial value of both highquality and common indica went up while the breakdown value dropped.(2) Storage time has a significant impact on amylose content, iodine blue value,fatty acid value, alpha-amylase activity, germination percentage and conductivity,especifically for the amylose content, iodine blue value and conductivity. Andstorage temperature has a significant effect on amylose content, fatty acid value andconductivity. Also, the fatty acid value was affected remarkably by moisturecontent.(3) Compared to common indica, there were obvious difference in growth rateof fatty acid value, gel consistency, conductivity and decline rate of iodine blue value, germination percentage, albuin, prolamin and taste value to high qualityindica within the same storage condition. And the rate of change to high qualityindica was bigger than common indica.(4) The taste value of high quality indica was significant positive correlatedwith iodine blue value and germination percentage, which was positive correlatedwith breakdown value and alpha-amylase activity. Meanwhile, the taste value wassignificant negative correlated with peak viscidity, hot paste viscosity, cold pasteviscosity, fatty acid value and conductivity, which was negative correlated withsetback value and amylose content. In contrst, the taste value of common indicawas significant positive correlated with iodine blue value and germinationpercentage, which was positive correlated with breakdown value. And the tastevalue was significant negative correlated with revial value and amylose content,which was negative correlated with peak viscidity, hot paste viscosity, cold pasteviscosity, fatty acid value, conductivity and gel consistency.(5) The transverse section of endosperm to fresh high quality indica, freshcommon indica and antiquated indica which stored360days were obsreved by SEMat1500times. The results showed that, crack was obsreved in the starch granule ofantiquated high quality indica. And the crack became obvious with the storagetemperature rose. In contrast, there wasn’t crack in the starch granule of commonindica with the same storage condition.(6) Through the correlation analysis between the taste value of high qualityindica and indicators, we found the taste value was very significant with iodineblue value, germination percentage, atty acid value and conductivity. According tothese indexes under different storage temperature,moisture content, otherindicators change rule and economic costs, finally we got the reasonable Storageconditions，that is13.5%moisture content, Storage temperature is not higher than20℃.