超声波结合气调包装对番石榴贮藏品质与生理的影响

【目的】了解超声波结合气调包装处理对番石榴贮藏品质及生理的影响,为番石榴采后贮藏保鲜提供参考依据。【方法】以珍珠番石榴为试验材料,分别用超声波(频率40 k Hz,输出功率360 W)处理番石榴果实5和10 min,晾干后用自发气调保鲜袋进行单果包装;以蒸馏水浸泡番石榴果实5 min,不套袋为对照(CK),3组果实均置于室温(5~15℃,相对湿度70%~85%)条件下存放,贮藏期间每6 d测定1次番石榴果实的营养品质和生理指标。【结果】超声波结合气调包装不仅能减缓番石榴果实营养品质和苯丙氨酸酶(PAL)活性下降、果实水分的散失,还可有效抑制番石榴果实的呼吸强度、质膜相对透性和过氧化物酶(POD)活性下降,延缓果实衰老;其中以超声波10 min结合气调包装处理的保鲜效果最佳,贮藏30 d后,番石榴好果率仍达81.82%,失重率仅为1.11%,果皮叶绿素含量、果实PAL活性及蛋白质、维生素C含量均高于CK在贮藏第18 d时的含量和活性,果实变形度、POD活性、质膜相对透性和呼吸强度则始终低于CK,贮藏时间比CK延长了12 d。【结论】超声波结合气调包装处理番石榴果实的保鲜效果良好,有利于延长番石榴果实的贮藏期限和保持原有的风味品质,以超声波处理10 min效果最佳,可用于番石榴采后保鲜。

Effects of ultrasonic treatment combining modified atmosphere package on quality and physiological changes of Psidium guajava during postharvest storage

Objective]Effects of ultrasound combining modified atmosphere package(MAP) on preservation quality and physiological changes of Psidium guajava fruits were studied in order to provide reference for its postharvest storage tech-nique. Method]Using Zhenzhu P. guajava as experiment material, the quality and physiological indexes of three groups were determined once every six days during postharvest storage at ambient temperature(5-15 ℃, relative humidity 70%-85%). The fruits were treated with ultrasound(frequency 40 kHz, output power 360 W) for 5 min or 10 min combined with MAP after drying. The fruits being soaked in distilled water for 5 min and no bag were taken as control group(CK).Result]The nutritional quality, phenylalanine enzyme(PAL) activity and total moisture of P. guajava was well main-tained with ultrasound combining MAP. Respiratory intensity, cell membrane permeability and peroxidase(POD) activity of P. guajava fruits were restrained, and senescence was delayed. Ultrasonic treatment for 10 min combining MAP presented the optimal preservation effects. After 30 days storage, good fruit rate reached to 81.82%, weight loss rate was only 1.11%, contents of chlorophyll, protein and vitamin C, PAL activity were higher than those of CK on day 18, deformation degree, POD activity, cell membrane permeability and respiration intensity were superior than those of CK, and the storage longevity prolonged 12 days than that of CK. Conclusion]Ultrasound combining MAP can reach good preservation effects on P. guajava fruits. It prolongs storage longevity and keeps the original flavour of the fruits. The best preservation method is ultrasonic treatment for 10 min, which can be used for P. guajava fruits postharvest preservation.