微波处理与涂膜对草菇控温贮藏保鲜的影响研究

探讨了微波杀菌、壳聚糖和黄原胶涂膜对草菇控温贮藏保鲜的影响.采用单因素试验比较不同加热火力、加热时间微波杀菌和不同配比壳聚糖、黄原胶涂膜的草菇保鲜效果,再根据单因素优选试验结果,选取微波时间、子实体包装规格、涂膜剂浓度(壳聚糖和黄原胶共混涂膜剂浓度)和贮藏温度为主要因素,以鲜度感观评分为指标,先微波后涂膜进行正交试验.结果表明,输出功率462 W微波加热15 s 或20 s对草菇具有较好的杀菌保鲜效果;涂膜处理保鲜效果均显著优于对照组;优化保鲜工艺:包装规格150 g,微波(462 W)处理时间20 s,涂膜剂浓度2.0%(壳聚糖∶黄原胶=1∶1)和贮藏温度15 ℃,在此优化条件下,草菇贮藏保鲜达216 h以上(＞9 d).

Effect of Microwave Treatment, Coating with Chitosan and Xanthan Gum, and Storage Temperature on the Storage Quality of Volvariella volvacea Fruit Bodies

The effect of microwave treatments using different output power levels and exposure times on the decontamination of Volvariella volvacea fruit bodies, and the effect of coating with different ratios of chitosan and xanthan gum on fruit body quality during storage, were evaluated using monofactorial tests. Monofactorial test results were then used as the basis for the optimization of microwave exposure times, packing weight, concentration of coating agent and storage temperature using orthogonal testing. Maximal decontamination and maintenance of fruit body quality was recorded when 150 g of mushrooms in a polypropylene box(170 mm×150 mm×65 mm)were exposed to microwave treatments of 462 W output power for 15 s or 20 s. Relatively low rates of weight loss and soft rot development, and higher sensory scores, were recorded for V. volvacea fruit bodies coated with a 1∶1 ratio of chitosan∶xanthan gum prior to storage. Optimal conditions for preserving V. volvacea fruit bodies were determined as follows: packing weight 150 g, microwave (output power 462 W) exposure time 20 s, concentration of coating agent 2.0%, and storage temperature 15 ℃. Under these conditions, the quality of V. volvacea fruit bodies was maintained during a storage period in excess of 216 h (>9 d).