响应面法优化非热式火龙果红糖膏渗透工艺

Optimization of Osmotic Technology of Non-Thermal Pitaya Red Paste by Response Surface Methodology

以红心火龙果和红糖为研究对象,采用5 ℃低温静置渗透方式制备非热式火龙果红糖膏。通过单因素试验考察糖液中红糖与火龙果物料比、红糖目数和火龙果果球直径3个因素对可溶性固形物含量、红糖完全溶解时间及果肉渗透前后硬度比的影响。在此基础上运用Box-Behnken响应面法设计3因素3水平试验,建立回归方程,运用期望函数优化多重响应分析。期望函数D=0.75时,得到最佳渗透条件为物料比1:0.9、果球直径2.0 cm和红糖目数20~40目,此时糖液中可溶性固形物含量为60.20%,红糖粉完全溶解时间240.10 h,硬度比0.22,与预测值的相对误差值分别为0.86%、0.63%、4.80%。所建立的回归模型及相关参数之间相关性较好,试验拟合度高,满足可溶性固形物含量较大、完全溶解时间短、硬度比相对较小的要求。最优条件得到产品的菌落总数、霉菌和酵母菌数均符合卫生标准,渗透过程中可能存在蔗糖缓慢转化为果糖、葡萄糖的现象。

In this work,non-hot pitaya red paste was prepared by static osmotic method at the low temperature of 5 ℃ using the red pitaya and brown sugar as the research object.The effects of the material ratio of brown sugar to pitaya fruit,the number of brown sugar mesh and the diameter of pitaya fruit ball on the content of soluble solids,the complete dissolution time of brown sugar,and the hardness ratio of pitaya fruit ball before and after osmosis were investigated by single factor test.On this basis,the Box-Behnken response surface method was used to design a three-factor and three-level test,and a regression equation was established.The approach of desirability function optimized the multi-objective approach,when the desirability function D=0.75,the optimal penetration conditions were as follows:the material ratio 1:0.9,pitaya fruit ball diameter of 2.0 cm,and brown sugar mesh 20~40 meshes.Under these conditions,the content of soluble solids in sugar solution was 60.20%,completely dissolved time of brown sugar was 240.10 h,and the hardness ratio was 0.22,the relative error of test results and the predicted values were 0.86%,0.63%,and 4.80% respectively.The correlation between the established regression model and the related parameters was good,the degree of fitting of the actual test was high,this condition met the requirements of large soluble solid content,short complete dissolution time,and relatively small hardness ratio.Under the optimal conditions,the total number of colonies,molds and yeasts of the product met the hygienic standards.Sucrose might be slowly transformed onto fructose and glucose during the osmosis process.