Study On Quality Improvement Of Instant Rice Noodle Prepared By Extrusion

Most rice noodles currently on the market need to be boiled for a certain period of time before they can be eaten.The traditional rice noodle production process is complicated and wastes raw materials.Extrusion technology can make the rice noodles reach a higher degree of maturation,and then through special treatment of the rice noodles,it can produce quick rehydration instant rice noodles,which has always been a research hotspot.This project intends to use twin-screw extrusion,aging treatment,vacuum freeze-drying and optimization of compounding to solve the current problems of large cooking loss,slow rehydration and poor taste of rice noodles.First of all,this paper uses Xinyang Indica rice as raw material to prepare rice noodles,and uses cooking characteristics,texture characteristics and sensory scores as evaluation indicators to optimize the extrusion process parameters.The results show that: from the comprehensive analysis of five indicators of cooking loss rate,gelatinization degree,strip breaking rate,texture characteristics,and color difference,the temperature of VI zone is 90?,100?,110?,and the screw speed is 140 r/min,160 r/min./min,180 r/min,the moisture content of the feed is 38%,40%,42%,and the cooling temperature is 30°C,35°C,and 40°C,the overall quality of the produced rice noodles is better.Taking sensory score as the evaluation index,the primary and secondary influence of the four factors is moisture>cooling die temperature>screw rotation speed>VI zone temperature.According to the orthogonal test analysis,the best process parameter is determined to be A2B3C2D2.That is,the moisture content is 40%,the screw speed is 180 r/min,the temperature of the VI zone is 100 ?,and the temperature of the cooling die is 35 ?.Second,explore the effects of soaking and aging conditions on the rehydration quality of rice noodles.The results show that through microstructure and response surface analysis,the interaction of the two factors of soaking time A and soaking temperature B can significantly affect the rehydration time of rice noodles.Among the17 samples of the response surface,8 samples were randomly selected for scanning electron microscopy.The results showed that the aging process with better pore size,uniformity and rehydration of the microstructure and micropores is immersion temperature 32?,freezing temperature-40 ?,soaking time 4 min.Using Design-Expert analysis,the optimal aging mode conditions for rehydration time were obtained and corrected: soaking time 4.4 min,soaking temperature 36°C,freezing temperature-40°C.The modified conditions are used for rehydration after aging treatment.The rehydration time is about 397 s,and the response surface model is feasible.Compared with the control group,the vacuum freeze-dried rice noodles after aging treatment have significantly reduced rehydration time,and increased cooking loss rate and strip breakage rate.Then,explore the effect of amylose on the quality of rice noodles.A single-factor experiment with three different amylose content of corn starch was carried out.The optimal addition amount of corn starch with 20% amylose content was 12% and 24%,and the optimal addition of corn starch with 30% amylose content was optimal.The amount is 12%,24%,36%.In the cluster analysis,the sensory scores are better in the first,third,and fifth categories.The sensory score ranges from 74.74 to 80.94,the amylose content of the compound powder ranges from 24.79 to 28.51%,and the water absorption rate of rice noodles ranges from 116 to 129.27.%,the cooking loss rate is4.77%~6.37%,the stripping rate is 6.06%~8.90%,the hardness is 2204.80~4187.38 g,and the chewiness is 1798.01~2638.78 g.Through single factor and cluster analysis,it is concluded that when the content of compound powder amylose is in the range of24.79%~28.51%,that is,when 20% amylose is added at 12%,24%,and 30% amylose is added at 12%,24%,36%,the quality of rice noodles is better.Then,after extrusion maturation,aging process and vacuum freeze-drying treatment,compared with the purchased commercially available rice noodles,the results show that compared with the commercially available rice noodles,the homemade rice noodles have a larger diameter and lower moisture content.However,the rehydration time is shorter;the cooking loss and stripping rate are not significantly different from those of the commercially available rice noodles;however,the commercially available rice noodles have better taste and texture characteristics.