Study On The Storage Of Fresh Rosa Roxburghii Tratt Fruit

Rosa roxburghii tratt originates in southwest China with special flavor and perfect value of nutrients, which belongs to the Rosaceae family and Rosa genus. The fruit have a higher content of ascorbic acid(As A)(21.85-22.54 mg As A per gram) and a high level of superoxide dismutase(SOD) activity. However, though many researches have been conducted on Rosa roxburghii tratt fruit in recent years including developing new products and the extraction of active components, there were few published data about fresh Rosa roxburghii tratt fruit storage. In this thesis ‘Guinong 5’ Rosa roxburghii tratt were used as experimental material, and researches included the changes of fruit quality and physiochemical indexes during the storage of different maturity and different controlled atmosphere(CA) storage conditions, the changes of ultrastructure of Rosa roxburghii tratt cell under different temperature of CA storage and comparing the changes of proteome of Rosa roxburghii tratt before and after the stage of storage.Different maturity of Rosa roxburghii Tratt fruits 70%(85d after anthesis), 80%(95d after anthesis) and 90%(105d after anthesis) maturity-degree of ‘Guinong 5’ Rosa roxburghii Tratt were storaged under the condition of 1±0.5oC with relative humidity 80% ~ 85% packed with preservative film. During the process of storage(0-105d), related quality and physiochemical indexes of Rosa roxburghii Tratt were determined. Results showed the fruits of 70% maturity maintained flesh firmness at a relatively high level, the contents of reducing sugar and As A decreased rapidly on the later phase of storage with poor sensory qualities. Furthermore, the fruits of 80% maturity showed a slow decline on flesh firmness, weight loss rate and decay rate; maintained higher contents of As A, total sugar and reducing sugar; delayed the rate of respiration and kept better qualities. The fruits of 90% maturity were ripening and senescence quickly during storage, shown as the decreasing of flesh firmness, the increasing of cell membrance permeability and higher rate of weight loss and decay. There were insignificant(p>0.05) difference in peroxidase(POD) activities among different treatments, except 15 th and 45 th day of storage. Except 45 th day of storage, there were significant(p<0.05) difference in polyphenol oxidase(PPO) activities among different treatments. There were insignificant(p>0.05) difference in the contents of malondialdehyde(MDA) among different treatments, except 15 th and 90 th day of storage. Among different maturities, 80% maturity should be suggested as the best harvest maturity of Rosa roxburghii Tratt in storage.Rosa roxburghii tratt fruit were stored at 1±0.5oC and 80%-85% relative humidity with four different atmosphere conditions including CK(0.03% CO2, 21%O2), B1(3-5% CO2, 3-5% O2), B2(3-5% CO2, 7-9% O2) and B3(3-5% CO2, 10-12% O2). To study the interacts and changes between antioxidant activities and reactive oxygen species of Rosa roxburghii tratt fruit during CA storage, relevant indexes were detected every 15 days.The results showed that the fruit under CA storage showed lower oxidative stress than CK group. The CA storage significantly delayed(p<0.05) the loss of As A, remained the activities of superoxide dismutase(SOD),catalase(CAT),ascorbic acid oxidase(AAO)and ascorbate peroxidase(APX); inhibited the levels of active oxygen(O2- and H2O2). It suggested that the condition of CO2 3-5% and O2 3-5% was better to keep the content of As A and GSH, higher activities of SOD and CAT, better effects on inhibition of O2- and H2O2.That should be suitable CA storage condition for Rosa roxburghii Tratt.Fresh Rosa roxburghii tratt fruit were storaged at three separate temperatures including 1±0.5oC(C1), 4±0.5 oC(C2) and 8±0.5 oC(C3) with the CA condition of 3-5%CO2, 3-5% O2, and RH:80%~85%. The changes of ultrastructure flesh cells of all treatments between fresh fruit and after 105 d storage were observed by using transmission electron microscopy. Results shown, on the first harvest day, flesh cell ultrastructure of fruits was compact, orderly, uniform and integrate. After 105 d of storage, the ultrastructure flesh cells of all treatments featured the characters of aging. The ultrastructure flesh cells of C1 suffered slight damage maintained the integrate structure of cells with slight distortion of cell skeleton and light plasmolysis; samples of C2 suffered destroy of cell structure, protoplasm degradation, cell wall distorted severely and cell contents were dissolved as flocculent; flesh cells of C3 had the most serious damage including the most destroyed structure of cell, serious phenomenon of plasmolysis, cell wall crinkle bended, cell organelle deformed or degraded and cell empty cavity. Overall, the low temperature storage has small damage on cell structure and Rosa roxburghii tratt fruit which were stored at 1±0.5oC showed relatively integrated cell structure. Rosa roxburghii tratt fruit should be stored at this temperature.Method of label free proteomic analysis was used to compare the changes of proteome of Rosa roxburghii tratt fruit between the stage of fresh fruit and the stage of after storage(105d) with CA conditions of 3-5%CO2, 3-5% O2 and RH:80%~85% at 1±0.5 oC. Results shown, 952 proteins were identified including 379 differently expressed spots(p<0.05). Among those differently expressed proteins, 197 proteins was up-regulation and 182 proteins was down-regulation after storage comparing with fresh fruit. During the process of aging, proteins of Rosa roxburghii tratt which had changed could be divided as energy proteins, stress response and defense proteins, signal transduction proteins as well as ripening and senescence proteins. Among them several proteins like SOD, CAT, eukaryotic translation initiation factor 3(e IF-3) and eukaryotic translation initiation factor 6(e IF-6) and lipoxygenase were increased after 105 d of storage. However, other energy proteins as F-ATPase subunit alpha and ATP synthase subunit alpha were decreased after 105 d of storage. Bioinformatics analysis illustrated that differently expressed proteins were mainly participated in 14 biological process, involved in 9 molecular functions and 14 cell components.