The Research Of Japonica Quality Indicators And The Main Volatile Substances Among The Japonica And Brown Rice And White Rice During Storage

This paper mainly studies japonica rice quality indicators and the difference of volatile substances among the japonica brown rice white rice in different storage conditions.The test of the 2014 harvest japonica samples were sealed humidifier Quenched,at 13.5%,14.5%,15.5%,16.5% moisture content were stored for 360 d at15?,20?,25?,30?respectively oxygen concentration were 2%,5%,8%,21% controlled by N2.We detected the quality indicators such as fatty acid,Lipase activity,viscosity and volatile substances in three different forms of existence of japonica,brown rice,and white rice based on GC-MS per month.According to the experimental analysis we can get mainly results as follow:1,The quality of rice was great influenced by storage time,temperature,the moisture content of rice and oxygen concentration.With the extension of storage time,the rice quality is deterioration and the higher temperature the more the moisture content,the faster rate of quality deterioration.Under the condition of high temperature and high moisture content,adjusting oxygen concentration can effectively reduce the rate of quality deterioration,while under the low temperature and low moisture content gas storage is meaningless.In order to extend the shelf life of rice and slowing the speed of the deterioration of rice quality during storage must be strictly controlled temperature and humidity.2,Analysis the changes of rice quality during storage applied dynamics.The relative error of kinetic model to predict lipase activity and fatty acid is between 0.2-10% and 1-12%,indicating that the model can better forecast quality changes of rice during storage.3,Through the principal component analysis,the different storage temperature on japonica,brown rice,white rice have different effect about the main volatile components.The main volatile components in japonica samples,the main volatile components in alcohols,ketones,and heterocyclic.Main volatile components in brown rice samples,under low temperature storage conditions,the main volatile components in alkane,alcohols and ketones;Under the condition of high temperature storage,the main volatile components in alkane and aldehydes.The main volatile components in white rice samples affected small,low temperature storage conditions,the main volatile components called ketones,aldehydes and acid ester;High temperature storage condition,the main volatile components called ketones and aldehydes.4,On the same storage period(90 d),volatile substances in the japonica,brown rice and white rice for testing and thtough the principal component analysis,during the storage period for 90 d,material effect was caused by ketones in japonica samples;In white rice samples,alkane affect obviously;All kinds of volatile components in brown rice function level is equal.In all kinds of samples with different storage period,volatile component contribution rate is different,and they have different characteristic volatile substances.