Effect Of Ethyl Pyruvate On Preservation Of Cherry

As a subordinate genus of Rosaceae,Prunus avium L.is a fruit that contains adequate active substances,vitamins,and essential trace elements.Cherry is rich in nutrition,but not easy to store.The biggest obstacle for circulation of cherry in the consumer market is that,the cherry is quite easily to be soft,brown,prone to rot and fruit deterioration after harvest,which caused huge economic loss.In this paper,the cherry"hongmanao"has been used as a research material.With ethyl pyruvate(EP)treatment,the relevant physiological indicators,such as sensory quality,physicochemical properties and biological activity components during storage were detected to explore the correlation of changes.It provides scientific basis and theoretical guidance for post-harvest preservation,storage and transportation of cherry"hongmanao"by ethyl pyruvate.The main contents and results of this study are as follows:1.Effect of ethyl pyruvate on the quality change of postharvest cherries:the cherry will have a series of quality changes after harvest.With the extension of storage time,the maturity of fruits will gradually increase until senescence deteriorates.Through the treatment of 300μL of EP with absorbent paper on the inner wall of 900 mL crisper,the changes of sensory quality,physicochemical properties and antioxidant activity of fruit such as hardness,mass loss,color,browning and decay rate were detected and the relevance of changes were explored.The results showed that EP could slow down the decrease of fruit hardness.The content of MDA in EP treated group was 61.3%lower than that in control group on 35 d.The relative electrical conductivity in EP group was 10.7%lower than that in control group,and the rot index and quality loss rate were observed at 42 d.There was an inhibitory effect on the increase,but there was no significant difference on the 42 d of storage.2.Preparation of starch-EP microcapsule and its effect on the postharvest preservation of cherries:EP is used as the core material,and starch octenylsuccinate is embedded into the wall material.Freeze-drying method was used to prepare yellowish powdery fresh-keeping materials,which improved the stability of EP and prolonged the EP action time.The embedding rate was 73.7%by RP-HPLC,3 g,6 g and 9 g microcapsule preservatives were stored in the 900 mL crisper of the treatment group respectively,the effective EP content was 700μL,1400μL,2100μL·900mL~-11 respectively,and the sensory quality,physicochemical properties,and bioactive substances content of cherry fruits after treatment were measured.The results showed that 2100μL EP of starch-EP microcapsules had good effect.At the end of storage,the decay index of starch wall material group was 24.7%lower than that of blank group,and the decay index of starch-EP microcapsule treatment group was 45.7%lower than that of blank group on64 d.The content of MDA in the starch-EP microcapsule-treated group was12.3%lower than that in the blank group.3.Preparation of chitosan-EP microcapsule and its effect on postharvest preservation of cherries:EP as core material,chitosan as embedded wall material,freeze-drying method to prepare powdery fresh-keeping material.The embedding rate was 84.6%determined by RP-HPLC,3 g,6 g,and 9 g microcapsule preservatives were stored in the 900mL crisper of the treatment group,the effective EP content was 800μL,1600μL,and 2400μL·900 mL-1 respectively.Changes in the quality of the treated cherries were tested and analyzed.The results showed that 1600μL EP of chitosan-EP microcapsule had better effect on maintaining cherry storage quality.On 64 d,the hardness of the 1600μL EP group was 27.3%and 36.4%higher than that of the blank group and the control group,respectively;and the blank group rotting index on the 24 d,it has risen to23.1%,but only 14.4%in the 1600μL EP group;the acidity content of the blank group was 19.2%lower than that of the 1600μL EP treatment group at 34 d,the control was 12.4%lower than the 1600μL EP treatment group,and the total amount of the 1600μL EP treatment group fruits.The polyphenol content was 1.05 times of the blank group.4.In order to screen wall materials and further determine the concentration of the core material,so as to achieve the best preservation effect,compare the embedding effect of microcapsules for two kinds of wall materials,the effect of sustained release and the preservation effect of cherries,the embedding effect and the preservation effect of two microcapsules for cherries were compared in the same period.Compared with starch octenylsuccinate,the high chitosan embedding rate was 84.6%;the hardness of chitosan-EP group fruits was 27.3%higher than that of the blank group,and was 7.7%higher than that of the starch-EP treatment group at 64 d;the browning index of the Chitosan-EP group was 7.3%lower than that of the starch-EP.In summary,chitosan is more suitable for the wall material of EP microcapsule.