坛紫菜膳食纤维的响应面优化超声复合酶法提取及其对鱼糜凝胶强度的影响

Optimization for ultrasonic assisted enzymatic extraction of soluble dietary fiber in laver Porphyra haitanensis and its effect on gel strength of surimi by response surface methodology

为促进坛紫菜Porphyra haitanensis高附加值产品的开发,提高坛紫菜的综合利用率,以坛紫菜为原材料,利用超声波破碎仪结合α-淀粉酶(质量分数1.0%)、糖化酶(质量分数1.0%)及中性蛋白酶(质量分数1.0%)酶法提取可溶性膳食纤维(soluble dietary fiber,SDF),并在单因素试验基础上,以可溶性膳食纤维提取率为响应值,选取酶解温度(A)、超声时间(B)、超声功率(C)设置3因素3水平进行Box-Behnken优化试验,并对添加SDF的冻藏罗非鱼鱼糜的凝胶强度及组织结构进行了观察。结果表明:优化得出的最佳提取条件为酶解温度50℃、超声时间40 min、超声功率为450 W,在此条件下SDF的提取率为23.96%±0.80%,与预期结果基本一致;测得坛紫菜SDF持水率为(4.68±0.08)g/g,膨胀力为(2.11±0.11)mL/g,持油率为(3.06±0.05)g/g,阳离子交换力为(1.28±0.13)mmol/g;分别以质量分数为0.1%、0.2%、0.3%的SDF添加至罗非鱼鱼糜中,0.2%添加量组罗非鱼鱼糜凝胶强度降幅为51.21%(空白组降幅为79.55%),且鱼糜凝胶空间结构最为致密均匀。研究表明,采用超声波辅助酶法能够显著提高坛紫菜SDF的提取率和品质,所得SDF可显著减缓鱼糜凝胶强度降低的程度。

In order to develop the high value-added products and to improve the comprehensive utilization rate of laver Porphyra haitanensis,the soluble dietary fiber(SDF)of the laver was extracted by ultrasonic crushing apparatus combined withα-amylase(mass fraction 1.0%),saccharase(mass fraction 1.0%)and neutral protease(mass fraction 1.0%).In the single-factor tests,the soluble dietary fiber yield was investigated under 5 factors and three-levels Box-Behnken test including enzymatic hydrolysis temperature(30,40,50,60,and 70℃),enzymatic hydrolysis time(20,40,60,80,and 100 min),addition of neutral protease(0.1%,0.5%,1.0%,1.5%,and 2.0%),ultrasonic power(270,360,450,and 630 W)and ultrasonic time(20,30,40,50,and 60 min)as the response value.Gel strength determination and scanning electron microscope(SEM)observation of surimi structure of frozen tilapia supplemented with SDF were carried out.The yield of SDF was found to be 23.96%±0.80%under optimal extraction conditions of enzymatic hydrolysis temperature at 50℃,ultrasonic time of 40 min and ultrasonic power of 450 W,which was basically consistent with the expected results.The SDF of the laver was extracted with water holding capacity of(4.68±0.08)g/g,expansion force of(2.11±0.11)mL/g,oil holding capacity of(3.06±0.05)g/g,cation exchange force of(1.28±0.13)mmol/g.The gel strength was found to be decreased by 51.21%in 0.2%SDF group and 79.55%in blank control group in tilapia surimi supplemented with 0.1%,0.2%,and 0.3%of SDF with the most dense and uniform spatial structure in the surimi gel in 0.2%SDF group,indicating that SDF can significantly delay the decrease in the surimi gel strength.The findings indicated that ultrasonic assisted enzymatic method significantly improved the extraction rate and quality of SDF from the laver,and that the SDF led to decrease in the surimi gel strength significantly,which provides technical support for the utilization of SDF in surimi industry.