Studies On Postharvest Hot Water Rinsing And Brushing Treatment And Combination With Yeast Antagonist On Presavation Of Sweet Cherry Fruits

The middle-mature sweet cherry fruits(Prunus avium L.cv.Van) were treated by postharvest hot water rinsing and brushing(HWRB) treatment and the effect of HWRB treatment on decay and quality,mechanism of physiology and biochemistry,and combinations of HWRB treatment and yeast antagonist on fruits were investigated.1.HWRB treatment was first used for sweet cherry fruits postharvest treatment refereed foreign studies.HWRB treatments at 60℃or 65℃for 20s were chosen for study referring to foreign research resuits and pre-experiment.Results showed that,60℃20s HWRB treatment could effectively reduce fruits decay and its development and delay stem brown. Fruit quality during storage was not affected by HWRB treatment which maintained fruit surface color and help accumulating the content of anthocyanins.Low temperature was benefit for keeping longer storage time and 14 days' storage was fit for good quality at shelf life.2.Balance of ROS(reactive oxygen species) metabolism and activity of resistance system were protected by 60℃20s HWRB treatment in order to delay fruit senescence.HWRB treatment reduced fruits respiration rate,kept high activity of SOD and CAT and content of ASA,and decreased contents of MDA as a result of maintaining cell membrane stability; Activities of POD and PPO were partly inhibited by HWRB treatment which help controlling fruits brown and delay senescence;High activity of PAL which be maintained by HWRB treatment could enhance resistance.3.65℃20s HWRB treatment might cause heat damage on sweet cherry fruits.Parts of treated fruits showed surface shrinking and brown;Contents of MDA and respiration rate of 65℃20s HWRB treated fruits were higher than the control.Activities of SOD,CAT and PAL were low but activities of POD and PPO were not inhibited.Though 65℃20s HWRB treatment reduced parts of fruits decay,but anyway this temperature was not fit for sweet cherry fruits postharvest fresh-keeping.4.60℃20s HWRB treatment could significantly killed or inactivated a large number of the epiphytic microbial population on fruit surface and inhibited germination of pathogen spores(Penicillium expansum and Botrytis cinerea) so as to reducing fruits natural decay and controlling the development of infected wounds.60℃20s HWRB treatment after inoculation with pathogen spores decreased infected wounds within 24h;Especially, HWRB treatment 6h after inoculation gave the lowest germination and completely inhibited wounds decay while 12h after inoculation also got low infected wound of fruits.5.Treating fruits with 60℃20sHWRB treatment and then dipping them into a cell suspension of C.laurentii showed the lowest fruit natural decay than separate treatment, and not affected fruits quality.Otherwise,the combination of HWRB and C.laurentii effectively controlled infected wounds that inoculated with two pathogen spores (Penicillium expansum and Botrytis cinerea) and completely controlled that with Botrytis cinerea which confirm the effect of combination treatments again.