Research On Formulation?process Of Extruded Reconstituted Rice And Its Physical?Glycemic Index Characteristics

Extrusion reconstituted rice is a kind of engineering rice which is made by extrusion technology to meet the nutritional needs of different people and select the corresponding food raw material combination.It's required not only to help the nutritional and functional design for individualized people,but also has the same sensory shape and cooking characteristics as ordinary rice,giving higher value than ordinary rice.At present,most of the extruded recombined rice is studied by adding vitamin and mineral materials to rice flour,or adding a small amount of functional raw materials.There is no mature reconstituted rice product specifically for diabetes and obesity on the market.The purpose of this paper is to develop a product with high protein,rich dietary fiber,low GI(Glycemic index)and rice physical characteristics through the research on the formula process and functional evaluation,so as to meet the needs of diabetes and obesity people for staple food,and to achieve effective control of blood sugar.The main research contents and results are as follows:(1)Multiple sets of samples were created by designing a combination of different protein,dietary fiber,and carbohydrate content,to carry out the sensory evaluation and instrument analysis of engineering rice quality.The corresponding relationship between palatability and texture in sensory evaluation and chewiness and hardness in texture analyzer was obtained.Through regression analysis of data,a comprehensive sensory evaluation index combining subjective and objective was formed,and the comprehensive evaluation method for the quality of recombined rice was established in this experiment.(2)According to the experimental design,the effects of five factors on the quality of reconstituted rice,including the number of raw materials,the moisture content of raw materials,the rotating speed of extruder,the barrel temperature of extruder and the feeding speed,were investigated.Within the scope of test selection,the parameters for each factor obtaining the highest score are respectively as follows: mesh number 80,water content 35.01%,rotating speed of extruder 139.75 rpm,barrel temperature 75.44?,extruder rotating speed 64.65kg/h.Then the response surface methodology(RSM)was used to design and analyze the effects of moisture content,rotational speed of extruder,feeding speed and barrel temperature on the quality score,texture,elasticity and chewiness of reconstituted rice,and the corresponding equation was obtained.Among them,barrel temperature was a significant factor(P<0.05).The results showed that when the moisture content of material was 32.97%,the speed of extruder was 179.20 rpm,the barrel temperature was 80.25?,and the feed rate was 59.80kg/h,the taste of reconstituted rice was the best.(3)The physical characteristics,flavor characteristics and nutritional characteristics of extruded rice were studied by using electronic teeth(texture instrument),electronic tongue,electronic nose and other instruments to assist sensory evaluation,and compared with ordinary rice(glutinous rice and japonica rice).In terms of texture,the rupture force and hardness data indicate that the reconstituted rice is higher than the ordinary rice.The reconstituted rice is soft and not sticky,and the taste is good.In terms of taste and smell,the reconstituted rice is not as so acidic as rice,but the salty,sweet,astringent and umami tastes are heavier than ordinary rice.From the perspective of microstructure,it can be seen that the natural rice has some cracks,while the structure of reconstituted rice is compact because of high pressure processing.Based on the results of nutrient detection,the reconstituted rice belonged to high protein and high fiber food.(4)The functional properties and GI value of reconstituted rice were studied by simulated digestion experiment in vitro and human physiological experiment.In vitro test results show that the GI value of the white bread?glutinous rice and reconstituted rice was 94.4?75.0 and 60.5,respectively.The Reconstituted rice's GI value was determined to be 52.7 by human trial,and it belonging to a low GI food.Compared with ordinary rice,it is more suitable for patients with chronic diseases such as diabetes and obesity.