| This paper focuses on Indica, a cultivar of rice which is up to eighty percent of total overstocked rice. On the basis of traditional spontaneous fermentation of rice noodles, It is the first time using lactic acid bacteria fermentation to product rice noodles and researching the mechanism of improvement of eating quality of rice noodles, mechanism of modified starch and formation of gel by lactic acid bacteria. Meanwhile, the processing technology of fermented rice noodles by lactic acid bacteria was discussed. The mathematic model and method evaluating the chewness of vermicelli and similar foods related to starch gel have been established. Consequently, the theory of using Indica to produce high quality rice noodle was established.Fermented by lactic acid bacteria, the gel strength, maximum strain, the ratio of extension rate to the section shrinking rate and plasticity of rice noodle were 230.6 kPa, 39.7%, 81.78% and 0.88 cm higher than the control sample, respectively. Young's modulus and the yield strength were 2.4KPa and 0.61 KPa lower than control sample, respectively. The results of sensory evaluation showed that the rice noodles fermented by lactic acid bacteria were smoother, softer and tougher than control. In the process of lactic acid bacteria fermentation, the structure of rice flour was changed by lactic acid and extracellular enzymes. The results indicated that the protein content of rice flour declined from 6.89% to 5.64% after treated by lactic acid. The GPC profile showed that the amylopectin of rice starch treated by extracellular enzymes is debranched and the number of average molecule polymerization and the average chain length decreased from 12676.3GLLK 61.2GLU to 11500.4% 45.0 GLU, respectively. The number of average molecule polymerization and the average chain length of amylose increased from 2975.3 GLLK 23.7 GLU to 3563.2 GLtk 28.4 GLU, respectively. The content of amylose increased from 12.33% to 17.34 at the end of fermentation.The analyses of scanning electron microscope showed that the granule of rice starch was eroded after fermentation and the small starch granule increased, the swelling power, the solubility and dilatability of gel volume increased respectively after fermentation. The analyses of TPA showed that the hardness of starch gel declined from 25395g to 24254g, springiness and resilience increased from 75.8%,88.1% to 79.3%,97.2%, respectively. The results of RVAand DSC indicated that the peak viscosity decreased 692 cp after pasting. The onset gelatinization temperatures were brought forward. The time of gelatinization was longer than control sample, the gelatinization enthalpy was increased. The result of X-ray diffraction showed that the crystal type of rice starch is unchanged after the fermentation, but the ratio of crystal area to amorphous area declined from 28% to 22%.Cultured by lactic acid bacteria, the content of lactic acid increased obviously within the first 16h.After 16h, it increased gradually. The longer the culture time, the higher activities of protease and amylase, the peak value is in the 120h. In the process of rice noodle fermented by lactic acid bacteria, the content of lactic acid and activities of protease and amylase all increased rapidly in the first 12h, and the protein content of rice flour decreased significantly, while the amylose content increased obviously hi the first 12h, but it increased slowly during 12-48h, the activity of protease and amylase began to decrease after 48h. The content of protein and amylose in the rice noodle remained unchanged. Exponential grow phase of lactic acid bacteria was 8h to 24h, and then kept stable grow phase after 24h. Whole milled rice fermentation was benefit to preparing rice noodle. The opportune fermented condition is: fermentation temperature and time are 30癈 and 12h, respectively.For mechanical properties, the correlation coefficient of extension rate/section shrinking rate, gel strength, maximum strain, apparent elasticity, plasticity, yield strength and the chewness of the or...
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