微波辅助提取美藤果蛋白工艺优化及性质研究

Optimization of microwave-assisted extraction process and properties of protein from Plukenetia volubilis

【目的】优化美藤果蛋白的提取工艺,并研究其加工性质,为美藤果蛋白的精深加工利用提供参考依据。【方法】以脱脂美藤果饼为原料,采用微波辅助碱溶酸沉法提取美藤果蛋白(记为MAPP),在单因素试验基础上,以液料比(A)、微波功率(B)和微波时间(C)为自变量,MAPP得率(Y)为响应值,通过响应面法优化其提取工艺,同时探究不同温度和pH对其加工性质的影响,并与碱溶酸沉法提取的美藤果蛋白(记为APP)进行比较。【结果】3个因素对MAPP得率的影响排序为微波功率>液料比>微波时间,其中微波功率影响极显著(P<0.01,下同),3个交互项影响均不显著(P>0.05),模型优化方程为Y=14.42+0.5075A+1.05B+0.4838C+0.0425AB+0.4225AC-0.1350BC-1.25A2-1.13B2-0.8725C2,得到MAPP提取的最佳工艺条件:液料比17∶1(mL/g)、微波功率645 W、微波时间62 s,在此条件下蛋白得率为14.46%,蛋白纯度为90.29%,高于APP得率(13.24%)。60℃热处理可增强美藤果蛋白的溶解性,50℃时持水率和持油率最大;当pH为2或9时,美藤果蛋白有较高的溶解性,且其起泡性及起泡稳定性、乳化性及乳化稳定性均为最高;相较于APP,在60和70℃时,MAPP的溶解性和持水性极显著提高,20~60℃范围内MAPP的持油率均高于APP,pH为4~7时MAPP溶解性极显著提高;在适当pH条件下起泡性及起泡稳定性、乳化性及乳化稳定性均得到改善。【结论】微波辅助碱溶酸沉法可提高美藤果蛋白得率,改善其加工性质。

【Objective】To enhance the extraction methodology of Plukenetia volubilis protein and investigate its processing characteristics to provide reference for the advanced processing and utilization of P.volubilis protein.【Method】A microwave-assisted alkali dissolution-acid precipitation method was used to extract P.volubilis protein(denoted as MAPP)from its cake.Based on a single-factor test,the extraction process was optimized by response surface methodolo-gy using liquid-to-material ratio(A),microwave power(B)and microwave time(C)as independent variables and MAPP yield(Y)as response value.Furthermore,the effects of varying temperatures and pH on MAPP’s processing properties were investigated,which were compared with alkali dissolution-acid precipitation extracted P.volubilis protein(denoted as APP).【Result】The effects of the three factors on the MAPP yield were ranked as microwave power>liquid-to-material ratio>microwave time,in which the effect of microwave power was extremely significant(P<0.01,the same below),and the effects of the three interaction items were not significant(P>0.05),and the model optimization equation was Y=14.42+0.5075A+1.05B+0.4838C+0.0425AB+0.4225AC-0.1350BC-1.25A2-1.13B2-0.8725C2.The optimal process conditions for MAPP extraction were obtained:liquid-to-material ratio of 17∶1(mL/g),microwave power of 645 W,and microwave time of 62 s.Under these conditions,the protein yield was 14.46%,and the protein purity was 90.29%,which was higher than that of the APP yield(13.24%).The heat treatment at 60℃enhanced the solubility of P.volubilis protein,the water holding rate and oil holding rate were the largest at 50℃;when the pH was 2 or 9,the solubility of P.volubilis protein was high,and its foaming and foaming stability,emulsification and emulsion stability were the highest;compared with APP,the solubility and water holding rate of MAPP were extremely significantly increased at 60 and 70℃,and the oil holding rate of MAPP was higher than that of APP in the range of 20-60℃,the solubility of MAPP was extremely significantly improved in the pH range of 4-7;the foaming and foaming stability,emulsification and emulsion stability were improved under the appropriate pH conditions.【Conclusion】Microwave-assisted alkali dissolution-acid precipitation can increase the protein yield of P.volubilis and improve its processing properties.