Study On The Changes And The Mechanism Of The Brown Rice With Different Moisture

Our country is a main producter of paddy in the world，and the year storage can achieve50bilion kilogram. It has not only saved massive warehouse capacity, but also saved themassive labor forces. Our country always uses paddy as its storage form, but withimprovements in grain warehousing conditions, we also has the condition to gradually getbrown rice as the main storage form. But we still lack data support and theory basis. Thispaper took “kongyu131” brown rice as the object of study, studied quality changes of thebrown rice after a storage of half a year under different moisture and temperature conditionsand carried on relevant analysis to various indexes.Temperature has a remarkable influnce on germination percentage.20℃below andmoisture lower than14%, six months of storage can maintain a good germination percentage.Observations by electron microscope showed embryo site gets distorted or broken duringstorage period, which possibly caused germination percentage to reduce; Failing number andfat acid value during storage period will increase unceasingly, and the higher storagetemperature and moisture are, the faster the increase gets. Low temperature and quasi lowtemperature storage donot affect the the two indexes much. Surface morphology researchshowed that fat acid value has a strong connection to surface injury and microorganismactivity.The oleic acid (C18:1) and the linoleic acid (C18:2) do not change much during thestorage process, and there is an extremely remarkable reversal correlation relation betweenthe two acids, that is to say, if the amount relatively increases for one kind of fatty acid, it willdecrease for the other fatty acid, so this is a “in inverse proportion” relation. Changes inmicro fatty acids during the storage process vary from one kind to another, but the mainregularity is showed in storage under30℃, which is kind of different from that of15℃and20℃for several kind of micro fatty acids. Maybe this is because high temperature causesthe fat acid value to increase too fast.The viscosity index for gelatinization has a remarkablechange during the storage period. Moisture has a distinct effect on peak viscosity, that brownrice of much moisture has a higher peak viscosity than that of little moisture after a certaintime of store.There are some quite differences between samples of various moistures in maintainingviscosity, final viscosity, attenuation value and resuscitation value under low temperature (15℃). But, however, with storage temperature rising, the differences get vague, and theinfluences of moisture on these indexes are not obvious either.After a certain time of store for endosperm cells, the radiant hierarchical structure in cellbecomes vague, surface of discontinuity reduces between cells and increases inside the cell,and the tendency is more obvious when under high temperature. After a certain time ofstorage, the compound starch granule breaks, resulting in the exposing of more small sizestarch granules, the edges and corners of compound granules become vague, and the structurebecomes sloppy, which can possibly affect the gelatinization temperature of starch.