The Research Of Retrogradation Influence Factors Of Rice Noodles And Its Mechanism

This subject through three aspects of the rice raw material properties, different processconditions, food additives, discusses the influence of rice noodles retrogradation quality. Atfirst, in order to research the influence of rice raw material on rice noodles retrogradation, thisstudy choose6merchant rice samples were used to measure amylase content, adhesivestrength, gelatinization properties of rice and make rice noodles. The result show thatXinyang hybrid xian-rice which have high amylase content（24.40%）,hard adhesivestrength（34.00mm）,low breakdown （2130Pa.s）, high setback（2650Pa.s） is suitable for ricenoodle making. It could cut down the time of rice noodles retrogradation. Thus it can be seenthat rice cultivars with high amylase content, hard adhesive strength, high setback are suitablefor rice noodles making，which speed up the degree of retrogradation and cut down the timeof retrogradation.Through the experiment to determine the main influence factors of the rice noodlesretrogradation are powder billet add water, retrogradation time, retrogradation temperature. Inaddition, by the single factor experiment, the optimum powder billet with water for about38%, optimum retrogradation time should be controlled in2⁵h, optimum retrogradationtemperature for4⁵℃. At the same time, the three factors in the response surface analysis,the results show that the influence of the rice noodles retrogradation significantly sequence:retrogradation temperature﹥powder billet add water﹥retrogradation time. And that the riceflour aging optimum process conditions: powder billet and water37.5%, aging temperature4℃, aging time of3h.Through the condition of the low temperature moisture, moisture at room temperature, airdrying to discusse the influence of the rice noodles retrogradation, the results show that lowtemperature moisture conditions article broken rate of the rice noodles <at room temperatureunder the condition of wet article broken rate of the rice noodles <air drying conditionsarticle broken rate of the rice noodles. At the same time, through the experiment the studydetermined corn starch, acid modified starch, potato modified starch and pullulan enzyme canspeed up the action of the rice noodles retrogradation, and the optimum adding amount was8%,8%,4%,0.1%.The experiment through the DSC, NMR, XRD, SEM method were used to disscuss therice noodles retrogradation mechanism and the results showed that rice noodles in lowtemperature moisture conditions, the heat enthalpy of rice noodles is opposite bigger, the retrogradation degree is larger; In the process of aging, A₂₂and A₂₁is larger, namely the ricewater liquidity is bigger, rice moisture content is larger, the quality of rice noodles is verygood; XRD experiment results show that under the condition of low temperature moisture,therice noodles diffraction intensity is the largest, has a high relative degree of crystallinity,crystal formation of crystal structure is better. Through the SEM diagram can be seen underlow temperature moisture, rice noodles gel structure more closely, distribution more uniform.Therefore, rice noodles retrogradation is the result of a variety of factors influence each otherand interaction each other.