The Physico-chemical Characteristic Change Of Fermentated Rice And The Forming Mechanism Of Rice Noodles Quality

This research is devoted to explore the change of properties of fermented rice noodles,which firstly optimized the conditions of fermentation; then explored the relevance betweenthe various changes of physical properties of fermented rice noodles and quality of ricenoodles; finally probed into the formation mechanism of the quality of rice noodles. Theresults was shown as follows:(1) The optimum conditions for the fermentation of rice by Lactobacillus plantarum is:incubation temperature of38℃; initial pH value of7, inoculation amount of4%.(2) Through the fermentation of rice noodles by microbe, the pH value of fermentationbroth will decrease, while the solid content will increase; the content and whiteness of starch,fatty acid, and reducing sugar will increase, while the content of protein, fat and ash willdecrease; the quality of fermented rice noodles is better than those without fermentation. Andthere are also some relevance between physicochemical index of rice starch, protein, fat, fattyacid, reducing sugar, whiteness, ash content and the quality of rice noodles.(3) After fermentation, the L*of rice noodles will increase; a*and b*will decrease; thegranularity will become finer; the average granularity of both surface area and volume willbecome smaller. But a large number of new chemical bonds or groups are not formed andmost of the original groups still exist. A slight increase in the proportion of crystallizationregion after fermentation of starch. Thus, a conclusion may be drawn that fermentation doesnot have much effect on the change of starch structure.(4) After fermentation, the transmittance of rice noodles will decrease; the cooking losswill go down first and then go up; the rehydration will first increase and then decrease; theresilience, cohesiveness, gumminess, chewiness and restoration will increase, while thehardness and adhesion will decrease. After fermentation most of the water in the rice noodlesis weak bound water (A22), and A22> A21. As the time of fermentation increases, A21will firstdecrease and then increase, while A22will first increase and then decrease.