Study On The Effect Of Twin Screw Extrusion On Physicochemical Properties Of Euryale Seed And Development Of Mixing Powder

Euryale seed is a nutritious,medicinal food with a high value for exploitation.In this study,the Euryale seed was processed using twin-screw extrusion technology to investigate the effect of twin-screw extrusion operating parameters on the physicochemical properties of the Euryale seed,and the functional active ingredients of Euryale seed polyphenols were analysed using high performance liquid chromatography.By adjusting the dosage of red date powder,xylitol and maltodextrin,a nutritive and delicious product of powder was developed by using the powder extruded by twin-screw.(1)Explore the influence of operating parameters on physical characteristics of euryale seed extrusion: In this study,single factor test was conducted to screen the influencing factors in the process of twin-screw extrusion,and the operating parameters were selected as follows: water content of material 20%-24%,barrel temperature 110-130℃,screw speed 150 r/min-250 r/min.On this basis,response surface test was carried out to analyze the model,factors and interaction of factors.Material moisture content in twin-screw extrusion operation parameters on the euryale extrusion for chroma L * significant effects,total flavonoids and total phenol content,barrel temperature on water absorption index of euryale extrusion and hydroxyl free radical clearance effect significantly,the screw rotation speed on diameter of euryale extrusion expansion rate,water soluble index,chroma L *,chroma a *,had a great effect on flavonoids content and total phenol content.Physicochemical properties of euryale seed changed after the twin screw extrusion treatment.In the response surface test of 17 groups of samples,the diameter expansion rate of euryale seed extruded is4.17,the water solubility index is 45.72%,the water absorption index is 8.92%,the chroma L* is 54.92,the chroma a * is 4.11.The maximum chroma b * was 14.09,total flavonoid content was 8.87 mg/g,polysaccharide content was 3.39 mg/g,total phenol content was 5.24 mg/g,hydroxyl radical scavenging rate was 91.33%,DPPH radical scavenging rate was 68.12%.(2)Using high performance liquid chromatography(HPLC)technique to analyze euryale seed polyphenol components: this test after extraction of twin-screw extrusion euryale seed polyphenols,and by using high performance liquid chromatography technology for its function of polyphenols active ingredient for qualitative and quantitative analysis,the method to detect the extrusion euryale seed polyphenols containing function of 4 kinds of active substances,respectively is: gallic acid,rutin,celery,quercetin.The moisture content of materials in the operation parameters of twin screw extrusion has a significant effect on the content of gallic acid,rutin and quercetin in euryale seed,and the screw speed has a significant effect on the content of apigenin.The highest content of gallic acid in euryale seed after extrusion is 21.648μg/g.The highest rutin content was 0.568 μg/g.Apigenin content was 1.798 μg/g.The highest quercetin content was 0.719 μg/g.(3)Development of mixing powder washing and blending: according to the water solubility index as the response value of the process optimization,determine the best operating parameters of twin screw extrusion euryale: water content of 22%,barrel temperature of 120℃,screw speed of 180 r/min.The mixing powder before and after extrusion was compared,and the structure of mixing powder was observed by scanning electron microscopy,and faults and cracks appeared on the surface after extrusion.Under these conditions,mixing powder produced was used as the raw material of powder blending,and nutritive jujube powder was selected as the auxiliary material,and the quality of powder blending was adjusted by maltodextrin and xylitol.The formula design was screened by single factor test to balance the sensory factors of powder blending,in which the added amount of jujube powder was 2.5 g to 3.5 g,xylitol was 2.0 g to 3.0 g,and maltodextrin was 1.0 g to 2.0 g.On this basis,response surface test was carried out,and sensory score was taken as the response value.Finally,the optimal formula of mixing powder was determined as 10 g of extruded mixing powder,3 g of jujube powder,1.8 g of xylitol and 1.8 g of maltodextrin.Under this condition,the flavor,color,taste and tonality of mixing powder were good and the acceptance level was high.