3种化学保鲜剂对草莓采后保鲜的影响

Effects of three preservatives on postharvest storage of strawberry

【目的】探讨柠檬酸钾、亚硫酸钠和维生素C等常用化学保鲜剂对草莓采后保鲜效果的影响,为其采后贮藏和运输提供安全、高效、低价的保鲜技术。【方法】以草莓品种法兰地为试验材料,分别置于2%的柠檬酸钾、亚硫酸钠和维生素C溶液中浸泡1 min,取出晾干后常温贮藏,以浸泡蒸馏水为对照,探讨3种化学保鲜剂对草莓外观、硬度、可溶性固形物含量、可滴定酸含量、维生素C含量及超氧化物歧化酶(SOD)酶活性的影响,筛选最适的保鲜剂及其浓度。【结果】与对照相比,3种化学保鲜剂对草莓外观及营养品质的变化均有明显影响,以2%维生素C处理的保鲜效果最佳,可延长贮藏时间,保持外观品质,有效缓解草莓硬度及可溶性固形物、可滴定酸、维生素C含量的下降,保持较高的SOD活性;贮藏至第7 d,草莓的可溶性固形物、可滴定酸、维生素C含量和SOD活性分别为9.60%、1.30%、87.72 mg/100 g和299.60 U/g,分别较对照高32.41%、9.68%、65.08%和44.40%。【结论】2%维生素C浸泡处理1 min能较好地保持采后草莓的色泽及营养品质,保鲜期延长至7 d以上,可用于草莓采后保鲜。

【Objective】Preservation effects of three common chemical preservatives namely potassium citrate,sodium sulfite and vitamin C on strawberry postharvest storage were investigated under room temperature,in order to provide safety,efficient and economically competitive preservation technology for strawberry.【Method】Flange strawberries used as tested material were soaked for 1 min in potassium citrate,sodium sulfite and vitamin C solution,respectively,with strawberries soaked in water as control.After being taken out and dried in the air,strawberries were stored at room temperature.Then,appearance,hardness,titratable acid content,vitamin C content and superoxide dismutase（SOD） activity of strawberry were determined,and effects of three preservatives on them were investigated,so as to screen optimal preservative and its concentration.【Result】Results showed that,the three preservatives had obvious effects on appearance and nutritional quality of strawberry,especially 2%vitamin C with the best preservation effect,because vitamin C prolonged storage time,maintained appearance quality,effectively reduced hardness,restrained decline of contents of soluble solid,titratable acid and vitamin C and maintained high SOD activity.Moreover,contents of soluble solid,titratable acid and vitamin C,and SOD activity were 9.60%,1.30%,87.72 mg/100 g and 299.60 U/g,respectively,and 32.41%,9.68%,65.08%and 44.40%higher than those of control.【 Conclusion 】 Colour and nutritional quality of postharvest strawberry are kept by soaking strawberry in 2%vitamin C for 1 min,and refreshing time can reach 7 days,therefore vitamin C can be used in preservation of postharvest strawberry.