Effect Of Degree Of Milling On The Change Of Nutrient Components And Texture Properties Of Lightly Milled Rice

Rice is one of the most important food crops on the earth.There are some enrich nutrients in brown rice, mainly containing sugars, protein, fat, vitamin, mineral substance and so on. The final product polished rice was obtained by grinding rice bran from brown rice which was gotten through cleaning-up, grinding grain shell. It was easily led to the loss of nutrients during processing rice. Recently, in the rice process of our country, the phenomenon that excessive process standing out and the precision of rice being over-pursued must bring some consequences:the milled rice rate will be reduced, the nutrition will be wastaged and the energy consumption will be increased.Therefore, with WaiYin7and KongYu131being experimental materials, this paper studied the preparation of lightly milled rice at different degree of milling, The nutrient content of lightly milled rice at different degree of milling, the texture properties of lightly milled rice at different degree of milling and the relationship between degree of milling and energy consumption. The studied result is as follows:1) The preparation of lightly milled rice at different degree of millingDuring the preparation, the length and width of rice were diminished, but the range of width diminished was less and that of length was more. The variational situation for degree of milling was as follows:in the process of milling rice, when degree of milling is at the range of6%-10%, the broken rice rate of both kinds are growing faster as it increases; and when it is2%-6%, their increasing range is relatively little. The germ-remained rate:that of both kinds decreases constantly as the increase of degree of milling. When the degree of milling is0-6%, it decreases more obviously, and at the range of6%-10%, it doesn't decrease evidently as the increase of degree of milling. In the point of the germ-remained rate, it is more appropriate that the degree of milling of rice should be controlled below6%.2) The nutrient content of lightly milled rice at different degree of milling Basic composition:The content of water decreased with a little change when the degree of milling was 0-6%; it had change hardly when6%-10%. Ash, fat, protein, crude fibre, these composition decreased more obviously when degree of milling was0-6%, and when it reached6%, their contents decreased gently; the starch content increased quite obviously when it was0-6%and the content increased more gently.VitaminB:the content of VB1,VB5,VB6,in rice were more and that of VB2,VB3were less. The connection between these composition and degree of milling was as follows:VB1,VB2,VB3,VB6:their contents decreased obviously with the increase of degree of milling when it was0-4%and the content didn't decrease obviously when4%-10%; VB5:its content decreased obviously with the increase of degree of milling when it was0-2%and its content didn't decrease obviously when2%-10%.Mineral elements:the contents of Mg and Ca were more and those of Zn,Fe,Cu, Mn were less. The connection between these composition and degree of milling was as follows:Mg,Zn:their contents decreased more obviously when degree of milling was0-6%, and they decreased gently when6%; Cu:it didn't diminish obviously as the increase of degree of milling, the trend increasing gently; Fe,Ca:their contents decreased more obviously when degree of milling was0-6%, and they decreased gently when6%; Mn:the decreasing range of its content was greatest when degree of milling was0-2%,and then, its content dreased gently with degree of milling increasing, and its content had change hardly when8%-10%.3) The texture properties of lightly milled rice at different degree of millingTexture property is up to the physicochemical property of rice, at the different degree of milling, texture property among the rice of same kinds change greatly because of the physicochemical property with great change. It varies more evidently when the degree of milling is0-8%and if it reaches8%-10%, these properties don't vary obviously.4) The relationship between degree of milling and energy consumptionthe energy consumption increases evidently, basically in the form of quadratic equation, as the milling degree enhances, energy consumption for milling proportion increases obviously when the grade of processing precision is enhanced, however, it makes some difference in the range of increase. The energy consumption is higher than other process grade when the degree of milling increases from8%to10%.