| This article mainly uses rice starch and rice flour as experimental materials.Firstly,the process optimization of the conditions of heat-moisture treatment of rice starch was carried out.Secondly,the effects of multiple heat-moisture treatment on the microstructure,thermal characteristics and digestion characteristics of rice starch and rice flour were studied.Finally,the quality of rice noodle was researched.The research content and results of full text are as follows:1.Through single factor and orthogonal experiment optimization,the optimal process conditions of heat-moisture treatment of rice starch were obtained:moisture content of 25%,treatment temperature of 110?,treatment time of 2 h.The verification experiment results show that the rapid digestion starch(RDS)content of rice starch treated under this condition is 76.19%±0.27,indicating that the digestibility of rice starch is the lowest after treatment under this condition.2.The physical and chemical properties of rice starch and rice flour,such as solubility and swelling force,amylose content,particle morphology,crystalline structure,short-range order structure,thermodynamic properties,gelatinization properties,and digestion properties,were measured under the conditions of multiple heat-moisture treatment.The results show that:(1)The solubility and swelling power of rice starch and rice flour show a gradient decline after multiple heat-moisture treatment.The lowest solubility is 3.84%and 3.81%and the swelling force is 8.47%and 6.04%.The amylose content presents a gradual upward trend,with the highest being 20.27%and 17.02%;(2)multiple heat-moisture treatment does not change the crystal structure of rice starch and rice flour,but still presents A-type crystals.The characteristics of individual particles gradually change,and the particles begin to interact with each other.;(3)Multiple heat treatment increased the initial temperature of gelatinization of rice starch and rice flour,from 61.19? and 61.17? to the highest 69.51? and 66.38%,and reduced the viscosity of each stage after gelatinization;(4)The digestibility of rice starch and rice flour was significantly reduced after multiple heat treatment,from 96.97%and 82.59%to 80.46%and 76.15%.The digestibility under the third heat-moisture treatment was the lowest,79.51%and 75.12%,respectively.Therefore,multiple heat-moisture treatment can have varying degrees of impact on the microstructure,thermal properties,and digestion properties of rice starch and rice flour.3.Rice noodle was made from the raw materials after multiple heat-moisture treatment.And the cooking characteristics,texture characteristics and sensory quality of rice noodle under different times of heat-moisture treatment were determined.The results show that:(1)The cooking characteristics of rice noodles have been improved after multiple heat-moisture treatment,and the more times the multiple heat-moisture treatment,the better the effect.The rice noodles breakage rate after 3 times of multiple heat-moisture treatment is the lowest;(2)With the increase in frequency of heat-moisture treatment,the hardness of rice noodles increased from 4,532.68 to 8461.32,the chewiness increased from 1903.91 to 2664.30,the viscosity decreased from-109.11 to-188.71,and the cohesion decreased from 0.86 to 0.61;(3)It is found that the total score of rice noodles after 3 times of multiple heat-moisture treatment is the highest,which is 45.95 points,indicating that the comprehensive quality of rice noodles after 3 times of heat-moisture treatment is the best.This thesis studies the effects of multiple heat-moisture treatment on the digestibility and other physical and chemical properties of rice starch and rice flour,analyzes the reasons for the changes in properties,and applies multiple heat-moisture treatment to rice noodle processing and discusses the results.It is hoped that it can provide new thinking and theoretical basis for multiple heat-moisture treatment to adjust the digestibility of rice noodles and the rice product processing industry. |
PDF Full Text Request