Study On Preparation And Quality Improvement Of Alum-free Mung Bean Noodle

The properties of peeled mung bean powder were studied,and the basic composition,thermodynamic properties,and gel properties of the peeled mung bean powder were measured.The microscopic characteristics of the peeled mung bean powder were also investigated by infrared spectroscopy,X-ray diffraction analysis and scanning electron microscopy.The extrusion technology was used to process the peeled mung bean powder.Based on the single factor experiments,the best peeling mung bean noodle production process was optimized through response surface methodology.The best aging process for noodle is obtained through experiments.The texture analyzer was used to determine the effect of acetylated di-starch phosphate,sodium alginate,and sucrose fatty acid ester on the texture and cooking characteristics of the alum-free mung bean noodle.The optimum additive compounding ratio was obtained by orthogonal test.The texture characteristics,cooking characteristics and microstructures of the noodle were measured,and the quality of the noodle was evaluated by a comprehensive sensory score.The alum-free mung bean noodle not only has a complete shape,strong taste,and low cooking loss,but also improves the nutritional value of the noodle under the premise of guaranteeing the quality of the noodle.At the same time,it also provides new ideas and lessons for the comprehensive utilization of mung beans.1.The peeled mung bean powder contained(9.67±0.47)% of moisture,(2.69±0.23)% of ash,(30.73±1.08)% of protein,(1.08±0.16)% of fat,and(55.83±1.46)% of starch.Amylose content was(15.07±0.22)% and amylopectin content was(40.76%±0.59)%.As the protein has a hindrance to the starch forming gel space,the intensity of the gel of peeled mung bean powder is inferior to that of the gel of mung bean starch.Infrared spectroscopy showed that the peeled mung bean powder had a typical absorption peak of mung bean starch.The results of X-ray diffraction showed that the crystal structure of mung bean starch belonged to the CA type crystal,and the intensity of the diffraction peak of mung bean was smaller than that of mung bean starch.The results of scanning electron microscopy showed that the mung bean starch granules were elliptical and the starch had irregularly attached proteins and lipids.The results of rapid viscosity analysis showed that the peeled mung bean powder had a lower gel viscosity than gel of mung bean starch,but the low temperature and thermal stability was better than that of mung bean starch gel.Thermodynamic analysis showed that the gelatinization temperature of peeled mung bean powder was higher than that of mung bean starch.2.Based on the single factor experiment,the optimal process for making alum-free mung bean noodle by extrusion using Design-Expert 8.0.6 software is 120 mesh(0.125 mm)particle size,a extrusion temperature of 152.62 °C,and two segments.The extrusion temperature was 112.35 °C and the moisture content was 28.83 %.Taking into account the actual operability,the extrusion temperature was adjusted to 150 °C,the extrusion temperature at the second stage was 110 °C,and the moisture content was 29 %.The best aging process was determined by determining the transparency and number of broken bars of the soup after cooking.The aging process was 4 h at 4 °C and 4 h at-4 °C.Under these conditions,the sensory score of the noodle was 92.3±0.7,the cooking loss rate was(6.74±0.18)%,the solids loss was(1.02±0.02)%,the soluble loss was(5.56±0.22)%,and the rehydration rate.The results were(265.6±0.8)% and breaking rate(12.0±1.0)%,which were significantly higher than those of mung bean starch noodle(P<0.05).3.Using texture analyzer to measure the hardness,chewiness,ductility and viscosity of the noodle,using the texture characteristics and cooking characteristics to examine the acetylated distarch phosphate,sodium alginate and sucrose fatty acid ester additives to the noodle of alum-free mung bean.The results showed that acetylated distarch phosphate can significantly increase the hardness and chewiness of the noodle but has no significant effect on ductility and stickiness,while at the same time it can reduce the cooking loss rate and breaking rate of the noodle;sodium alginate can significantly reduce the ductility of the noodle.Simultaneously with stickiness,it can slightly improve the hardness and chewiness of the noodle,and reduce the loss rate of cooking and breaking of the noodle;sucrose fatty acid ester can significantly reduce the cooking loss rate and breaking rate of the noodle,but has a negative impact on the texture characteristics of the noodle.4,The optimal compounding ratio of acetic acid diamyl phosphate was 5 %,sodium alginate 0.5 % and sucrose fatty acid ester 0.1 %.Under this condition,a noodle was prepared and the loss rate of cooking was(4.01±0.12)%,the loss of solids was(0.97±0.02)%,the loss of solubles was(3.04±0.24)%,and the rate of rehydration was(241.4±0.4)% and break rate(6.4±0.1)% both were significantly higher than those of no noodle added with compounding additives.They were very close to the acceptable levels of mung bean starch noodle.The results of texture characteristics showed that the hardness of the noodle added with additives increased.It was(6523±83)g,the chewability was improved to(1844±4)g,and the ductility and viscosity were reduced to(-3.12±0.14)g·s,-4.93±0.34,respectively,indicating that the compounding additive can significantly improve the noodle's Texture characteristics.The microscopic observation showed that the additive can improve the microscopic morphology of the alum-free mung bean noodle,the wrinkles and pores are significantly reduced,and the surface of the noodle becomes smooth.