Extraction Of Dietary Fiber From Bamboo Shoot Residue And Optimization Of Processing Parameters Of Its Biscuit

In this paper,the technological parameters of preparing active dietary fiber from bamboo shoot residue by composite enzyme method were optimized by response surface method.The physical and chemical properties of the active dietary fiber from bamboo shoot residue were studied.The active dietary fiber from bamboo shoot residue was applied to the biscuit,the optimum formula of the biscuit was developed,the baking conditions were optimized,and the biscuit quality was analyzed.The specific research contents and conclusions are as follows.1、The active dietary fiber of bamboo shoot residue was prepared with the complex enzyme of cellulase:papain:α-amylase=1:1:1,and the soluble dietary fiber（SDF）yield of bamboo shoot residue was used as the judgment basis.On the basis of single factor test,response surface method was used to obtain the optimal preparation parameters:adding 1.7%（papain34 u/mg,α-amylase68 u/g,cellulase170 u/g）enzyme amount,enzymatic hydrolysis time of 1.6 h,solid-liquid ratio of 1:20,enzymatic hydrolysis temperature of 50℃,under this condition,the yield of bamboo shoot residue SDF was 15.613%,the yield of bamboo shoot residue insoluble dietary fiber（IDF）was45.419%,and the yield of bamboo shoot residue TDF was 61.0%.2、The analysis results showed that the bamboo shoot residue contained more dietary fiber,the total dietary fiber（TDF）content was 58.57%,the soluble dietary fiber（SDF）was 12.24%,and the insoluble dietary fiber（IDF）was 46.33%.The results showed that IDF and TDF had good water holding capacity（WHC）,swelling capacity（WSC）and oil holding capacity（OBC）.WHC of IDF and TDF was 13.48 g/g and 9.07g/g,WSC was 4.60 g/g and 2.90 g/g,OBC was 23.69 g/g and 16.12 g/g,respectively.In vitro experiments,the adsorption capacity of SDF,IDF and TDF on NO₂^-and cholesterol were measured by adjusting pH2.0 and pH7.0 in simulated intestinal and gastric environments.The results showed that the order of NO₂^-adsorption capacity was IDF>TDF>SDF,while the order of cholesterol adsorption capacity was SDF>TDF>IDF.Moreover,the adsorption capacity of the three dietary fibers was all affected by pH value..When pH2.0,the NO₂^-adsorption forces of IDF was 991.17 ug/g;When pH7.0,the cholesterol adsorption capacities of SDF was 10.95 mg/g.3、The best formula of active dietary fiber biscuit of bamboo shoot residue is:wheat flour 94 g,bamboo shoot residue dietary fiber 6 g,olive oil 16 g,milk powder 15g,stevia glycoside water 34 g,salt 1.5 g,baking powder 1 g;The best baking conditions were:surface fire 170℃,bottom fire 130℃,baking time 18 min.4、The moisture,alkalinity and peroxidation values of bamboo shoot residue dietary fiber biscuits were in line with the national standards.The results of color difference and texture showed that the addition of dietary fiber made the colors of biscuits were darkened and deepened,and the hardness,brittleness and chewability were increased.