为了解决面包货架期短的问题,该实验研制出一种对面包具有保鲜防腐、改善品质的复合乳化剂。利用响应面分析法研究单月桂酸甘油酯、聚甘油脂肪酸酯和硬脂酰乳酸钠对面包品质以及面包细菌菌落总数抑制情况的影响。在单因素试验的基础上,进行Box-Behnken试验设计,以面包中细菌菌落总数、面包比容和面包硬度为优化指标,得到最优的乳化剂组合:聚甘油脂肪酸酯添加量0.75%(质量分数),单月桂酸甘油酯添加量0.60%(质量分数),硬脂酰乳酸钠添加量0.15%(质量分数),以此配方制备的面包比容达5.87 mL/g,硬度为474.4 g,与对照组比较,面包比容提高了20%,面包硬度降低了22%,在30 ℃、湿度70%条件下面包保质期比对照组3 d保质期延长了4 d。该复合乳化剂能显著改善面包品质,延长面包货架期。
In order to solve the problem of short shelf life of bread, this study developed a composite emulsifier to prevent corruption of bread and improve its quality. The effects of glycerol monolaurate, polyglycerol fatty acid ester and sodium stearyl lactate on the quality of bread and the inhibition of microbes were studied by response surface methodology. Experiments were designed using combination of single factor method and Box-Behnken design. The colony count, bread specific volume and bread hardness were used as the testing indexes by the response surface analysis. And the bread comprehensive score for the final index was used as the response value. The optimized formulation was with 0.75% polyglycerol fatty acid ester, 0.60% glycerol monolaurate and 0.15% stearoyl lactylate. By this formulation, the specific volume was 5.87 and the hardness was 474.4. Compared with the control group, the specific volume of bread was effectively improved 20% and the hardness of bread was decreased by 22%. It extended the shelf life of bread over four days at 30 ℃, 70% of the humidity. The quality was improved and the shelf life was extended significantly by the optimized formulation.