鲜切莲藕复合保鲜剂的优化及保鲜效果研究

为保持鲜切莲藕货架期的感官及营养品质,选取氯化钙、阿魏酸和乙醇3种保鲜剂进行单因素实验,以总容差ΔE^*、失重率和菌落总数为响应值,通过响应面设计优化最佳配方并验证其保鲜效果。结果表明,氯化钙、阿魏酸和乙醇复配能有效改善鲜切莲藕的贮藏品质。经方差分析和回归拟合确定复合保鲜剂最优配比为氯化钙质量分数0.68%、阿魏酸质量分数0.18%、乙醇体积分数15%(均用无菌水配制)。通过验证,贮藏12 d后鲜切莲藕的ΔE^*为8.64,失重率和菌落总数分别为2.85%和7.26 lg(CFU·g^-1), 与预测值相近;复合保鲜剂还能够维持鲜切莲藕的硬度及微观结构,减缓可溶性固形物、抗坏血酸等营养物质流失,抑制酚类物质含量下降及可溶性醌的积累。本研究结果可为鲜切莲藕复合保鲜剂的研发及提高鲜切莲藕贮藏品质提供理论依据和参考。

Optimization and Preservation Effect of Compound Preservative for Fresh-Cut Lotus Root

To maintain the sensory and nutritional quality of fresh-cut lotus roots during shelf life, three preservative agents, calcium chloride, ferulic acid and ethanol solution, were selected for single factor experiment. Then, the preservative formula was optimized by response surface methodology using the ΔE ^*, the weight loss rate and the aerobic bacterial count as response indexes, and the preservation effect of the optimized preservative on fresh-cut lotus root was verified. The results showed that combination of the three preservative agents had a significant effect on short-term storage of fresh-cut lotus roots. The optimal formula was determined by variance analysis and regression fitting to be calcium chloride 0.68%(m/m), ferulic acid 0.18%(m/m), and ethanol 15%(v/v). All the above solutions were prepared with sterile water. In the verification test, the ΔE ^*, the weight loss rate and the aerobic bacterial count of fresh-cut lotus root were determined as 8.64, 2.85% and 7.26 lg (CFU·g^-1) after storage for 12 days, respectively, which were similar to the predicted values. It can also maintain the hardness and microstructure, retard the loss of nutrients like soluble solid and ascorbic acid, inhibit the decrease of phenolics content and the accumulation of soluble quinones in fresh-cut lotus roots. The results can provide theoretical basis and reference for the research and development of compound preservatives to improve the storage quality of fresh-cut lotus root.