3种化学保鲜剂对草莓采后保鲜的影响

【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。

Effects of three preservatives on postharvest storage of strawberry

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 con-centration. [Result]Results showed that,the three preservatives had obvious effects on appearance and nutritional qual-ity 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 preserva-tion of postharvest strawberry.