采后赣南脐橙热水处理的保鲜效果

Research of the preservation effect on postharvest Gannan navel orange by hot water treatment

为研究热水处理技术在柑橘类水果采后保鲜中的应用可行性。试验以江西省赣南脐橙为试材,设计2因素(温度和时间)5水平均匀试验,分别考查热水处理后赣南脐橙贮藏品质相关指标(呼吸速率、可溶性固形物含量和硬度)和贮藏发霉情况,并研究了热水处理对赣南脐橙青、绿霉病原菌(意大利青霉和指状青霉)孢子的致死作用机制。综合分析,得出赣南脐橙热水处理较优条件为:50℃,5 min。该条件处理后的赣南脐橙呼吸速率最低,为42.89 mg CO_2/(kg·h)。25℃温箱保藏20 d,该处理组赣南脐橙均未发病,优于对照组。加赣南脐橙皮到病原菌孢子悬液中进行热水处理,病原菌孢子死亡率检测及Hoechst 33342/PI荧光双染色结果显示,赣南脐橙皮成分与热对病原菌有协同抑杀作用,病原菌孢子细胞膜受到损伤。50℃,5 min热水处理应用于赣南脐橙采后保鲜具有可行性。

In order to study the feasibility of hot water treatment technology applied to citrus fruits postharvest preservation, two factors （temperature and time） and five level uniform experiments were carried out to study the effect of different heat treatment on the storage quality, mildew during the storing at room temperature, and the lethal effect on spores suspension of Penicillium italicum and Penicillium digitatum. The results showed that the optimum hot water treatment conditions of Gannan navel orange was 50℃ , 5 min. Under this heat treatment conditions, the respi- ration rate of navel orange was the lowest of 42. 89 mgCO2/（kg· h） ; no mildew during 20 days storage period at room temperature ; pathogenic spore suspension was treated by heat and peel of Gannan navel orange. The results suggested that Gannan navel orange peel composition and hot water had combinative inhibiting and killing effect on pathogenic spores, better than the control group. Moreover, pathogenic spore cell membrane was damaged obviously showing with Hoechst 33342/PI fluorescence double staining. The conclusion is that hot water treatment （50 % , 5 min） was feasi- ble to preserve postharvest Gannan navel orange.