Effects Of Different Extrusion Process Parameters And Starch Sources On Processing Quality Of Dog Food

During extrusion,the quality of dog food will be affected by the change of technological parameters,starch types and content.The aim of this paper is to explore the effect of extrusion parameters and different starch sources on the quality of dog food.The optimum processing parameters are obtained by regression analysis combined with mathematical model of bulk density.The details are as follows:(1)The single factor experiment of different extrusion parameters on the extrusion quality of dog food showed that the extrusion quality of dog food was the higher when the moisture content was 28%,the opening area of template material was 200 mm2/t/h,the die temperature was 130?,and the screw speed was 240 rpm.(2)Response surface analysis was used to optimize the extrusion process parameters and the mathematical bulk density model of dog food.The results showed that all the parameters significantly affected the product quality,especially the water content and screw speed.Based on the regression analysis results,the optimum parameters for dog food extrusion were obtained in Design Export 8.0: moisture content 27.8%,die temperature 132?,screw speed 234 rpm.It was found that R2=0.9088 was fit by the test data into the mathematical model of bulk density,and the fitting degree was high,which indicated that the model had a good prediction effect on the bulk density of dog food.(3)The physical and chemical properties of wheat,rice and potato flour were analyzed.The effects of three starch materials of dog food were analyzed by mixing design.The results showed that the extrusion ratio of dog food was the lowest,the crispness of rice formula was the worst,and the hardness of potato flour formula was the highest.The experiment data were substituted into Design Export 8.0 software to optimize the proportion of three starch sources: wheat: rice: potato flour ratio 0:0.5:0.5;wheat: rice: potato flour ratio 0.25:0.25:0.5;wheat: rice: potato flour ratio 0.5:0.25:0.25.In summary,the dog food with better quality can be obtained by using the optimized technological parameters and bulk density model.The addition of rice and potato is beneficial to extrusion,the wheat can play a role in improving crispness.