Research On Developing And Characteristic Of Microwave-Vacuum Drying Of The Dried Rolls Of Tremella And Bean Milk Cream

The dried rolls of bean milk cream is one of the traditional distinguishing bean products in china , which is welcomed by people and has broad market prospects.Basis on the conventional process of the dried rolls of bean milk cream,the high quality Tremella produced in GuTian city was used in this research and the Tremella juice was extracted by using hot water extraction method.The Tremella juice was appropriately added to the soybean milk to develop the dried rolls of Tremella and bean milk cream;The uniform experimental design method was adapted to optimize the production technique of the dried rolls of Tremella and bean milk cream.Microwave-vacuum drying characteristics of the dried rolls of Tremella and bean milk cream was also discussed in the article.The main results of the research were showed as follows:（1）Study on developing and critical production technology of the dried rolls of Tremella and bean milk creamOn the basis of the single factor experiments,the L₉ （3⁴） orthogonal experiment design was employed to optimize the critical production technology parameters of the dried rolls of Tremella and bean milk cream.The results showed that the optimal technology parameters of the dried rolls of Tremella and bean milk cream were as follows:the mass ratio of Tremella to soybean = 5:100(w·w^-1),the Tremella and soybean milk concentration 2.2°Béand pH value 7.0.The verification test was carried out by using the optimal processing parameters and the results showed that the yield of the dried rolls of Tremella and bean milk cream was 5.11 g·（100mL）^-1 and the toughness reached up to 0.7136kg.Furthermore,the rehydration capability of the dried rolls of Tremella and bean milk cream was also significantly improved comparing with the dried rolls of bean milk cream,which were 4.22 g·g^-1,3.29 g·g^-1respectively,there existed significant differences in statistics （p<0.05）.（2） Research on the quality improvement of the dried rolls of Tremella and bean milk creamThe comprehensive assessment of the dried rolls of Tremella and bean milk cream was used as measure index and the uniform experiment design was adopted to obtain the optimal proportion of food additive.The results showed that:the best proportion of the food additive were 0.041%sucrose ester,0.026%lactate and 0.11%compound phosphate.Under this condition,the defoaming effect of the bean milk cream was good and the yield of the dried rolls of Tremella and bean milk cream was also increased 0.32g·（100mL）^-1,which reached up to 5.43g·（100mL）^-1.The sensory quality of the dried rolls of Tremella and bean milk cream was excellent.The tensile strength and elongation rate of the dried rolls of Tremella and bean milk cream reached up to 29.83 kg·（cm²）^-1 and 32.67% respectively.The comprehensive evaluation score of the products was given 93.To compare with the blank group,the tensile strength and elongation rate of the dried rolls of Tremella and bean milk cream were promoted 9.47 kg·（cm²）^-1and 11.51% respectively.（3） Research on microwave-vacuum drying characteristics of the dried rolls of Tremella and bean milk creamThe quadratic orthogonal rotary combination was used for experimental design and the dynamic mathematical model was established as follows:（microwave mass ratio power X₁,chamber vacuum X₂,drying time X3,microwave-vacuum drying velocity Y₁,rehydration rate Y₂）Y₁=4.72724+0.49854X₁+0.32688X₂-0.08583X₁²+0.12189X₂²+0.114X₁X₂Y₂=5.24702+0.17227X₁+0.2846X₂-0.23528X₁²-0.08502X₂²-0.18578X₃²+0.19375X₁X₂The experimental results of variance analysis showed that the two mathematical regression model were significant（p<0.01）and the lack of fit were not significant . There was goodness of fit for the two above regression equations（p<0.01）.The response surface analysis methodology was used to optimize the process parameters of microwave-vacuum drying of the dried rolls of Tremella and bean milk cream.After taking comprehensively account of the importance of various index and the production cost,the optimal parameters combination of microwave-vacuum drying of the dried rolls of Tremella and bean milk cream could be achieved as follows:microwave mass ratio power31 W·g^-1,vacuum pressure-80kPa and drying time 8min.Under this condition,The drying rate and rehydration rate of the dried rolls of Tremella and bean milk cream could reach 6.14g·min^-1and 5.58g·g^-1 respectively.To compare with the oretical value,the relative error was only±1.44% and±2.96% respectively.The result of variance analysis showed there were not significant differences in statistics（p>0.05）.It proved that the regression model equation was reliable,which provided the scientific reference for the industrialization application of microwave-vacuum drying of the dried rolls of Tremella and bean milk cream.Through comparing with the quality of the dried rolls of Tremella and bean milk cream obtained by microwave-vacuum drying and hot-air drying,the following results could be got:the former not only had good odor and interity,but also the brightness which reached 59.6633±0.0305 was better than the latter.The latter brightness was only 59.5967±0.0115 and the shape was also not so good.Through the analysis of variance between them that there existed significant differences （p<0.05）.In addition,the rehydration capability of the former was also obviously better than the latter.Both at the same condition after water 10min,the rehydration ratio of the dried rolls of Tremella and bean milk cream obtained by microwave-vacuum drying reached 5.03 g·g^-1,while the rehydration ratio of the dried rolls of Tremella and bean milk cream obtained by the traditional hot-air dry was only 4.22 g·g^-1,there existed significant differences in statistics （p< 0.01）.