| Considering the fermented rice noodles usually have obvious acidic taste,which can’t be generally accepted by consumers,we would like to adopt alkali treatment to eliminate the acidic taste of fermented rice noodles and improve the quality of fermented rice noodles as well.Alkali treatment tends to make the milling of grains easier and enhances the appearance,flavor,and texture of starchy foods.Rice products are altered by soaking rice in an alkali solution to change the physicochemical properties of rice flour.Noodles are altered in terms of their quality characteristics by adding an appropriate amount of alkali.Since there aren’t many studies on making rice noodles by adding alkali mixed rice flour.Therefore,this paper adds sodium bicarbonate into rice flour and then makes semi-dried rice noodles,and it is essential that we investigate the impact of sodium bicarbonate addition on the physicochemical properties of rice flour,as well as the quality characteristics of semi-dried rice noodles and storage quality.In this study,fermented rice flour was used as the research object in order to first examine the impact of sodium bicarbonate addition on the physicochemical characteristics of rice flour.After that,we examined how adding sodium bicarbonate affected the quality of fermented semi-dried rice noodles,and we obtained the optimal amount of sodium bicarbonate addition to improve the quality of semi-dried rice noodles by principal component analysis.Based on these results,the impact of sodium bicarbonate somewhat on fermented semi-dried rice noodles’ storage quality was examined by observing changes in the quality of semi-dried rice noodles with and without the addition of sodium bicarbonate during low-temperature storage.The following are the primary research components of this paper:(1)It was investigated how sodium bicarbonate affected the physicochemical qualities of fermented rice flour.Hydration characteristics showed that the addition of small amounts of sodium bicarbonate(0.02%～0.1%)would have improved the waterholding and water-binding capacity of rice flour.Farinograph and thermal properties showed that with the increase of sodium bicarbonate addition,the dough absorption,dough development time,dough stabilization time,pasting onset temperature,pasting peak temperature,and pasting termination temperature were all increased.Pasting and rheological properties indicated that the addition of a small amount of sodium bicarbonate(0.02%～0.1%)could have increased the peak viscosity,trough viscosity,final viscosity,shear pressure,energy storage modulus,and loss modulus of rice flour.However,when sodium bicarbonate was added 0.2%～0.5%,the physicochemical properties such as water-holding,water-binding capacity,pasting viscosity,energy storage modulus,and loss modulus of rice flour were gradually decreased.(2)It was investigated how sodium bicarbonate affected the qualitative properties of fermented semi-dried rice noodles.Cooking properties results indicated that the addition of small amounts of sodium bicarbonate(0.02%～0.1%)could decrease the breakage rate of semi-dried rice noodles.Textural properties and sensory evaluation showed that the addition of a small amount of sodium bicarbonate(0.02%～0.1%)could be improved the hardness,chewiness,and sensory score of semi-dried rice noodles.XRD results indicated that the addition of sodium bicarbonate would not change the crystal structure in semi-dried rice noodles,and the addition of a small amount of sodium bicarbonate(0.02%～0.1%)could have increased the crystallinity of semi-dried rice noodles.LF-NMR showed that the addition of a small amount of sodium bicarbonate(0.02%～0.1%)could have increased the bound water content and decreased the weakly bound water content and free water content in semi-dried rice noodles.SEM results indicated that the addition of a small amount of sodium bicarbonate(0.02%～0.1%)would enhance the starch-protein interactions in semi-dried rice noodles,and enable the formation of an orderly and stable network structure between starchprotein.However,when sodium bicarbonate was added at 0.2%～0.5%,the breakage rate of semi-dried rice noodles was gradually increased,and its quality characteristics such as hardness,chewiness,sensory evaluation,crystallinity,and bound water content were gradually decreased.Finally,the principal component analysis showed that the highest quality and overall score of semi-dried rice noodles were obtained at 0.1%of sodium bicarbonate addition.(3)It was investigated how sodium bicarbonate affected the storage quality of fermented semi-dried rice noodles was studied.During the cold storage period of 90 days,the pH and moisture content of semi-dried rice noodles in both the control group(without sodium bicarbonate)and experimental group(with sodium bicarbonate)were decreased,and the pH value of semi-dried rice noodles was higher in the experimental group compared to the control group,and the moisture content of semi-dried rice noodles in the experimental group was not significantly different from that in the control group.The total number of bacterial colonies of semi-dried rice noodles in both the control group and experimental group increased,and the total number of bacterial colonies of semi-dried rice noodles was higher in the experimental group compared to the control group.Cooking properties results indicated that the breakage rate and cooking loss of semi-dried rice noodles in both the control group and experimental group were increased,and the cooking loss of semi-dried rice noodles was higher in the experimental group compared to the control group.Textural properties indicated that the hardness and chewiness of semi-dried rice noodles in the control group were increased with the increase in storage time,while at 90 d of storage,the hardness and chewiness of semi-dried rice noodles in the experimental group were decreased.Color changes results indicated that the L*values of semi-dried rice noodles in both the control group and the experimental group were decreased and the b*values were increased,and the L*values of semi-dried rice noodles in the experimental group were all lower than that in the control group and b*values were significantly higher than that in the control group.XRD results indicated that the crystal structure of semi-dried rice noodles did not change during storage,and the crystallinity of semi-dried rice noodles in both the control group and experimental group increased,which indicated that the aging of semi-dried rice noodles in both the control group and the experimental group has increased during storage.According to the analysis shown above,we concluded that the moderate addition of sodium bicarbonate has an improving effect on the quality of semi-dried rice noodles.However,the addition of sodium bicarbonate would increase the pH of semi-dried rice noodles,and cause microbial multiplication during storage,which would result in lower cooking quality and poor taste in semi-dried rice noodles,and it wasn’t suitable for storage. |
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