Studies On Prediction Models For Fruit Decay And Shelf-Life Of Postharvest Chinese Bayberry

In this study, Chinese bayberry fruit(Myrica rubrieb.et Zucc.Duchesne.Wu Zhong) were stored at different temperatures(0,5,10,15 and 20℃). Changes in decay incidence and quality were investigated during storage.and a prediction model for shelf life based on ethanol content was developed. The results were as follows:1. During storage, decay index, weight loss and ethanol content of Chinese bayberry fruit were rised, and showed positive relationship with temperature;firmness, springiness, TSS, TA, total sugar, reducing sugar and Vc contents of Chinese bayberry fruit decreased, and showed negative relationship with tempe- rature. Low temperature storage inhibited the respiratory rate and ethylene production, maintained higher levels of CAT, SOD, APX and POD activities, delayed the senescence development and inhibited fruit decay incidence during storage.Highter temperature storage accelerated the increase of total anthocyanin and total phenolic content during the initial storage period and the decrease of these during zhe remainder of the experiment.Refrigerated storage inhibited the decease of antioxidants contents, maintaine higher antioxidant activity and fruit quality in Chinese bayberry. According to sensory assessment, decay index was used as the characteristic index of shelf-life of bayberry fruit and the shelf-life was over when decay index reached to 20%.2. Freshly Chinese bayberry fruit were stored at different temperatures (0,5,10,15 and 20℃). Changes in decay index of bayberry fruit were determined during storage. The kinetic model of decay index with respect to storage time and temperature was developed based on the Gompertz equation and Arrhenius equation and Activation energies(Ea) were 6.72×104J/(mol·K), R2 was 0.953. The models was verified with the fruits stored at 2,7,12 and 17℃. and the Relative Prediction Error was 2.69%. The results showed that the prediction were acceptable.3. Freshly Chinese bayberry fruit were stored at different temperatures (0,5,10,15 and 20℃). Changes in ethanol content, ethylene production and CO2 production of bayberry fruit were determined during storage and ethanol content showed positive relationship with decay index. The kinetic model of ethanol content with respect to storage time and temperature was developed based on Arrhenius equation and Activation energies (Ea) were 770KJ/(mol·K), R2 was 0.989.A model for decay index based on ethanol content was developed according to the linear relationship between decay index and ethanol content(R2=0.944),and the models was verified with the fruits treated with MeJA, and the Relative Prediction Error was 8.26% which showed that the prediction were acceptable. The results suggest that shelf life of Chinese bayberry fruit can be accurately predicted at the storage temperature from 0 to 20℃by the prediction model for shelf life based on ethanol content.