采前喷施拮抗酵母菌对草莓采后贮藏性能的影响

[目的]研究采前喷施拮抗酵母菌以提高草莓贮藏性能,减少采后损失.[方法]采用葡萄有孢汉逊酵母(Hanseniaspora uvarum)和季也蒙毕赤酵母(Pichia guilliermondii)对草莓采摘前3 d进行喷施处理,测定不同浓度酵母菌菌悬液对草莓常温贮藏[25 ℃、相对湿度(RH)90%~95%]病害的抑制效果以及最佳浓度酵母菌悬液对果实冷藏[(2±1)℃、RH 90%~95%]性能的影响.[结果]常温贮藏结果显示:采前喷施拮抗酵母菌显著降低果实腐烂指数(P<0.05),提高商品率,能较好地保持果实外观品质.1×106 CFU？mL-1复合酵母菌和1×108 CFU？mL-1单一酵母菌组果实商品率较高,可作为最佳冷藏试验浓度.冷藏试验结果表明:采前喷施拮抗菌能抑制果实硬度和维生素C含量的下降,减轻果实的腐烂,且腐烂指数显著低于对照组(P<0.05),其中复合菌处理组商品率高达85%,显著高于单一处理组(P<0.05).但采前喷施拮抗菌对草莓色泽、可溶性固形物(TSS)和pH值没有显著影响.处理组的超氧化物歧化酶(SOD)、过氧化物酶(POD)、多酚氧化酶(PPO)、过氧化氢酶(CAT)和β-1,3-葡聚糖酶(GLU)活性均高于对照组,丙二醛(MDA)含量低于对照组,且低浓度复合菌处理组果实冷藏效果好于高浓度单一酵母菌处理组.[结论]采用低浓度1×106 CFU？mL-1的复合菌菌悬液采前喷施,较其他处理能更有效提高草莓果实抗性,延长贮藏寿命,因此可以作为一种提高草莓采后贮藏性能的生物防治方法.
[Objectives]Applying antagonistic yeasts to strawberries in the field to enhance their storability and reduce postharvest losses was studied. [Methods]Strawberry fruits were treated with single and composite antagonistic yeast, Hanseniaspora uvarum suspension and Pichia guilliermondii suspension before 3 days of harvest, then the efficacy of different yeast treatments on postharvest diseases of strawberries at 25 ℃ with relative humidity(RH)90%-95% and storability was investigated. The yeast treatments with better antagonistic activity were selected to apply to strawberry during storage[at(2±1)℃ with RH 90%-95%]and to examine their efficacy on the postharvest diseases and storability of strawberries. [Results]The results showed antagonistic yeast treatments before the strawberries were harvested could significantly reduce their decay index, as a result, improve their commodity rate(P<0.05)at 25 ℃ with RH 90%-95%. The treatments of 1×106 CFU？mL-1 complex yeast and 1×108 CFU？mL-1 single yeast showed a better antagonistic activity compared with other treatments and thus were used for strawberries[at(2±1)℃ with RH 90%-95%]. The cold storage experiment suggested that antagonist yeast treatments could maintain fruits’ appearance quality, firmness and vitamin C content. During storage, the decayrate of treatment groups was significantly lower(P<0.05)than that of the control. Commodity rate of the fruits treated with the composite H.uvarum and P.guilliermondii was up to 85%, while that of the control was only 25%. There’s no difference in total soluble solids(TSS), pH between treatments and the control. The activity of enzymes including superoxide dismutase(SOD), peroxidase(POD), polyphenol oxidase(PPO), catalase(CAT), and β-1, 3-glucanase(GLU)of treatment groups were much higher than that of the control. The accumulation of malondialdehyde(MDA)of treatment groups was less than that