| The decrease in modern physical activity leads to a decline in energy requirements,and in the diet of modern residents,the proportion of high-fat,high-sugar,and high-calorie foods continues to increase,causing chronic diseases such as obesity.On the other hand,due to the accelerated pace of life and irregular diet,it has caused some people to experience imbalanced nutritional intake and malnutrition.Therefore,it is necessary to increase dietary fiber intake in the daily diet to achieve "thickness and thinness." Consumers' expectations for products are increasing,and the market has put forward new nutritional requirements for convenience foods.This paper mainly discussed the research on the production of convenient porridge by twinscrew extrusion.The experiment took japonica,wheat,corn,glutinous rice,millet,and oats as research objects.The effects of raw material components on the quality of the product after extrusion and expansion were determined.Through the D-optimal mixture design,the formula of instant porridge was optimized,and the optimal distribution ratio between raw materials was determined.The twin-screw extrusion method was used to process the raw materials,and the process parameters in the process were optimized to determine the best process parameters.Finally,orthogonal experiments were performed to optimize the effect of microwave hot air composite drying on product rehydration.The main conclusions were as follows:1.The composition of six grain raw materials was analyzed to explore the correlation between the basic composition of several grains and the characteristics of extrusion and expansion.Expansion performance,bulk density,water solubility index,water absorption index,texture and other indicators were used to reflect the swelling performance of the product.Correlation analysis was performed with the contents of starch,protein,fat and other ingredients in the raw materials to find the intrinsic characteristics of the swelling characteristics and the composition.The results showed that the puffing characteristics of japonica,wheat,and glutinous rice are better than those of corn,millet,and oat.Among them,glutinous rice was superior in swelling degree,bulk density,water solubility index,gelatinization degree,hardness,and crispness.Correlation analysis showed that the swelling degree was significantly positively correlated with the total starch and amylopectin content,negatively correlated with the protein content,and significantly negatively correlated with the crude fat content;the water solubility index was extremely significantly positively correlated with the protein content,and was significantly correlated with the total The starch content was extremely significantly negatively correlated;the degree of gelatinization was extremely significantly positively correlated with the total starch content,and it was extremely significantly negatively correlated with the protein and crude fat content.2.Through single-factor experiments,the effects of the addition of various grain raw materials on the rehydration rate,gelatinization degree,and sensory evaluation of the product were studied,and the addition of japonica rice was determined to be 40% to 50%,and the range of wheat addition was 20% to 30%.The amount ranged from 12% to 23%,the added amount of corn ranged from 4% to 8%,the added amount of millet ranged from 2% to 6%,and the added amount of oats ranged from 2% to 4%.The D-optimal blend design was used to optimize the formula.The results showed that the optimal formula of the grain extruded product was 45% by mass of rice,25% by mass of wheat,17% by mass of glutinous rice,6% by mass of corn,and millet by mass.4%,oat mass fraction 3%.3.Optimized the process parameters in the twin screw extrusion process,selected the three factors that have the greatest impact on the extrusion expansion effect: material moisture content,extrusion temperature(the temperature of the fourth zone of the screw),and the speed of the screw.Through single-factor experiments,studied each factor Impact on the physical and chemical properties of the product.Response surface experiments were used to optimize the best process parameters for twin-screw extrusion and puffing: the material moisture content was 20%,the screw speed was 210r/min,and the extrusion temperature(the temperature of the fourth zone of the screw)was 135°C.The material was processed according to the optimal parameters and the product quality obtained was the best.4.Using the rehydration rate as an index,the effect of microwave hot air composite drying treatment on the product was studied.Considering the drying process of the product comprehensively,the effects of the four factors of microwave time,microwave power,hot air drying time and hot air drying temperature on the rehydration rate of the product were studied.The results showed that the optimal composite drying conditions were microwave power of 12 Kw,microwave time of 10 min,hot air drying temperature of 90 ° C,and hot air drying time of 50 min.Under these conditions,the rehydration rate of the product was 296% and the rehydration time was 6min.The product appearance was better. |
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