Study On The Physical And Chemical Properties Of Different Gelatinization Glutinous Rice Flour

In order to study the physicochemical properties of different gelatinization glutinous rice flour,this paper uses Huangchuan glutinous rice as raw material to change glutinous rice by hot air method(control different temperature and time)and back-adding method(controlling the amount of pre-gelatinized cassava starch added).The gelatinization degree of powder,the relationship between different gelatinization degree glutinous rice flour and water absorption rate was discussed.The physicochemical properties of different gelatinization glutinous rice flour were explored,which provided the basis for the application of high gelatinization glutinous rice flour in food.The effect of powder gelatinization on the quality of dried dumplings.The research results are as follows:(1)Due to the influence of temperature and time,the water absorption rate of glutinous rice flour prepared by hot air method decreased firstly and then increased.When the gelatinization temperature is 100°C,and the hot air treatment time is 4h,the water absorption rate of glutinous rice flour was the highest.After the glutinous rice powder is added with the pre-gelatinized tapioca starch,the water absorption rate continued to increase with the increase of the added amount.When the pre-gelatinized tapioca starch is added at 5%,the water absorption rate of the glutinous rice flour is the largest.When the degree of gelatinization is about 60%,the method of adding back makes the water absorption rate of the glutinous rice powder increase more than that of the hot air method.(2)The gelatinization properties and thermodynamic properties of different gelatinized glutinous rice flours were analyzed.It was found that the peak viscosity of glutinous rice flour produced by hot air method showed a decreasing trend with the increase of gelatinization degree,and the rebound value was also reduced.Adding different proportions pre-gelatinized tapioca starch changes the gelatinization degree of glutinous rice flour.The peak viscosity tends to decrease,but the rebound value will increase.The DSC test found that the enthalpy value of the glutinous rice flour prepared by the hot air method was lowered.The enthalpy value of the glutinous rice flour added with the pregelatinized tapioca starch was also reduced,but the degree of reduction was smaller than that of the former.With the increase of temperature and hot air drying time,the freezing and thawing rate of glutinous rice flour will gradually decrease,indicating that increasing the temperature and increasing the hot air time can improve the freeze-thaw stability of glutinous rice flour.Increasing the amount of pre-gelatinized tapioca starch addition,and the freezing and thawing rate of glutinous rice flour also gradually decreased,indicating that the addition of pre-gelatinized tapioca starch can also improve the freeze-thaw stability of glutinous rice flour.Under the conditions of different temperature and hot air drying time,the gel consistency of glutinous rice flour increased first and then decreased.When the hot air treatment time was 0.5h,the gel consistency of glutinous rice flour was the largest;with the increase of pre-gelatinized tapioca starch,the gel consistency of glutinous rice flour showed a trend of increasing first and then decreasing.When the amount of pregelatinized tapioca starch was 2%,the gel consistency was the largest.In addition,by measuring the swelling power of different gelatinized glutinous rice flours,it was found that both the hot air method and the back-adding method can increase the swelling power of the glutinous rice flour.Different gelatinized glutinous rice flours were observed by colorimeter and SEM.The results showed that the L* values of glutinous rice flour decreased with different temperature and hot air drying time,and the a* value of glutinous rice flour decreased significantly.From the b* value,the overall color of glutinous rice flour was yellowish and as the degree of gelatinization increases,the yellow value increases significantly.The addition of the method does not have much impact on the overall quality of the glutinous rice flour.It can be seen from the scanning electron micrograph that the glutinous rice powder treated by the hot air method and the back-adding method is not much different from the original powder.(3)The dry glutinous rice balls made of different gelatinized glutinous rice flours were analyzed by the degree of collapse,texture analyzer and sensory evaluation.It was found that the dryness of the dried dumplings increased with the change of temperature and hot air drying time.The increase in the amount of pre-gelatinized cassava starch added,the degree of collapse of the dry dumplings decreased.The results of TPA showed that the hardness of the dried glutinous rice balls prepared by the hot air method first increased and then decreased,and the cohesiveness increased.The dry glutinous rice balls made of glutinous rice flour added with pre-gelatinized tapioca starch,which hardness decreased significantly,but cohesiveness increased.The more pre-gelatinized tapioca starch was added,the worse the chewiness.Sensory evaluation showed that the sensory score of the dried glutinous rice balls made by the hot air method was lower than that of the original powder.The dry glutinous rice balls added with pre-gelatinized tapioca starch have little difference in hardness,viscosity,elasticity,appearance and flavor,and the dried glutinous rice balls made of the original powder have little difference and can be added in an appropriate amount.