响应面法优化鲅鱼抗氧化肽发酵条件

摘要

为减少加工废弃物蛋白所造成的环境污染，提高水产品的利用率，探索了回收利用鲅鱼（ Spanish mackerel）加工后富含蛋白质的废弃物，以寻找制备鲅鱼抗氧化肽的最佳生产条件。借助Design-Expert数据处理软件对苏云金芽孢杆菌Hy-4发酵产抗氧化肽的条件进行优化；在单因素试验的基础上，利用Plackett-Burman试验设计法对影响发酵制备鲅鱼抗氧化肽的培养条件进行筛选。确定了影响发酵液总抗氧化活性的3个主要影响因素（P＜0．5）为发酵温度、培养基初始pH和料液比；在此基础上，利用最陡爬坡实验逼近3个关键因素的最大响应区域，再利用Box-Behnken试验设计及响应面分析法进行回归分析，通过求解回归方程得到产抗氧化肽的最优条件为：发酵时间48 h，发酵温度30℃，培养基初始pH 6．8，接种量2％，料液比1．45 g／50 mL，菌龄24 h。经过验证，发酵液总抗氧化活性达到537．73 U，较优化前提高了57．2％，与回归方程的预测值570．11 U相比，相对误差为5．7％，说明模型能够较好地预测菌株Hy-4发酵产抗氧化肽发酵液的总抗氧化性。%In order to improve the utilization efficiency of aquatic products and reduce the environmental pollution caused by waste protein, this paper explored the retrieving and using of Spanish mackerel processing wastes that are rich in protein, thus to search for the optimum conditions for preparing antioxidant peptides from Spanish mackerel, reduce the production cost and improve the economic benefit.Using waste proteins from Spanish mackerel production as substrate and bacillus thuringiensis Hy-4 as fermentation strain, Design-Expert software was applied to optimize the conditions for antioxidant peptides production.On the basis of single factor experiments, Plackett-Burman design was utilized to evaluate the effects of six variables influencing antioxidant peptides preparation from Spanish mackerel, including fermentation time, fermentation temperature, initial pH, inoculum quantity, ratio of material to solvent and cell age.Among the six variables studied, fermentation temperature, initial pH and ratio of material to solvent had significant effects on the total antioxidant activity of fermentation solution ( P <0.05 ) .Steepest ascent method was used to approach the optimal region of the total antioxidant activity.The regression analysis was further carried out using Box-Behnken design and response surface analysis.By solving the regression equation, the highest antioxidant peptides production was obtained at fermentation time 48h, fermentation temperature 30 ℃,initial pH 6.8, inoculum quantity 2%, material-to-solvent ratio 2.9%, and cell age 24h.The total antioxidant activity of fermentation solution reached to 537.73U, increased by 57.2%compared to the initial 342.02U.Compared with the predicted value of regression equation 570.11U, the relative error is 5.7%, illustrating that the model can better predict the total antioxidant activity of fermentation solution fermented by Hy-4 .