响应面优化小麦粉制备脂肪替代物的酶解工艺

摘要

以响应面法优化耐高温α-淀粉酶酶解小麦粉制备脂肪替代物的酶解工艺条件,并建立数学模型.以持水性、DE值为指标,通过单因素试验确定底物浓度、酶解时间、酶添加量的取值范围,采用Box-Behnken设计寻找制备脂肪替代物的最优工艺条件.经过Design-Expert 8.0软件预测出最优工艺参数:底物浓度(质量分数)25.60％,酶添加量2.33 U/g,酶解时间6.77 min,在此条件下持水性最大为282.25％.通过验证试验测得持水性为273.69％,表明模型的预测较为准确.在此基础上,对最优条件下脂肪替代物的凝胶性质和微观结构进行了初步研究评价,结果表明脂肪替代物的凝胶强度随溶液质量分数增加而增大,其分子结构受酶解作用而遭到破坏.%The thermostable α-amylase was utilized to produce wheat flour-based fat substitute,the enzymatic hydrolysis process condition was optimized through the response surface methodology,and the mathematical model was established.With dextrose equivalent (DE) and the water holding capacity as indicators,the value ranges of substrate concentration,enzyme dosage and enzymatic hydrolysis time were ensured through the single factor experiment,and the Box-Behnken design was used to search for the optimum condition of producing fat substitute.The Design-Expert 8.0 was used to predict the optimum process parameters:25.60％ of the substrate concentration (mass fraction),6.77 min of hydrolysis time,2.33 U/g of the enzyme dosage.Under this condition,the maximum of water holding capacity was 282.25％.The results from the validation experiments showed that the water holding capacity was 273.69％,which indicated that this model was more accurate.Based on this,under the optimum condition,the gel property and microstructure of the fat substitute were preliminarily studied and evaluated,and the results showed that the gel strength of fat substitute was increased with the increase of mass fraction of the solution,and the molecular structure was destroyed by enzymatic hydrolysis.