层层自组装可食性涂层在蓝莓常温保鲜中的应用

Application of layer-by-layer edible coating on blueberry preservation at room temperature

目的优化层层自组装可食性涂层的工艺参数,延长蓝莓常温保鲜期。方法以"绿宝石"蓝莓(Vaccinium rhododendraceae)为试验原料,以失重率和糖酸比为单因素的评价指标,考察不同浓度壳聚糖(chitosan,CS)、羧甲基纤维素钠(sodium carboxymethyl cellulose,CMC-Na)、甘油以及晾干时间对层层自组装可食性涂层保鲜效果的影响,并采用正交试验设计获得层层自组装可食性涂层对蓝莓采后常温保鲜效果的最佳参数。结果层层自组装可食性涂层最佳的工艺参数为CS浓度为6 mg/mL、CMC-Na浓度为10 mg/mL、甘油浓度为0.06mL/mL、晾干时间50min。在此条件下,蓝莓常温保鲜期可以达到12d,蓝莓失重率为(23.97±2.64)%,明显优于对照组失重率(33.04±3.39)%。结论本研究优化后的层层自组装可食性涂层处理蓝莓可减缓其贮藏期内的失重率、糖酸比下降速率,有利于蓝莓的常温保鲜。

Objective To optimize the construction process parameters of layer-by-layer edible coating to extend the freshness period of blueberry at room temperature.Methods The blueberry named Emerald(Vaccinium rhododendraceae)was used as raw materials,the weight loss rate and sugar/acid ratio were used as single factor evaluation indexes for exploring the effects of the concentration of chitosan(CS),sodium carboxymethyl cellulose(CMC-Na),glycerol and drying time on the preservation efficiency of the blueberry.Subsequently,the orthogonal design was applied to obtain the optimal parameters of the edible coating on blueberry in room temperature.Results The optimal coating parameters for layer-by-layer edible coating on blueberry preservation were:CS concentration was 6 mg/mL,CMC-Na concentration was 10 mg/mL,glycerol content was 0.06 mL/mL,drying time was 30 min.Under the conditions,the freshness period of blueberries could reach 12 d,the weight loss rate of blueberry was(23.97±2.64)%,which were significantly better than that of the control group[weight loss:(33.04±3.39)%](P<0.05).Conclusion The treated with the optimized layer-by-layer edible coating can significantly slow down the weight loss rate and sugar/acid ratio of blueberries,which provides theoretical supports for the practical application of this technology in fruit and vegetable preservation.