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The fresh postharvest golden needle mushroom (Flammulina velutipes) sporocarp has a high moisture content and crisp texture, but it still has high physiological activity and respiration, leading to senescence and quality deterioration. Treatments with 1-methylcyclopropene (1-MCP) and polypropylene (PP) crispers were used to study the changes of lignification and softening of F. velutipes during storage. The main findings were as follows: the crisper packaging could effectively prolong the storage time of F. velutipes; either the 1-MCP treatment, crisper packaging or the combination of the two treatments could significantly inhibit the accumulation of lignin and the decreases in the contents of cellulose and pectin, and had certain inhibitory effects on the activities of enzymes involved in lignification and softening including phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), cellulase (Cx), pectin methylesterase (PME) and polygalacturonase (PG). Among them, the inhibitory effect of the crisper packaging was higher than the 1-MCP treatment, while the combination of the two treatments was the best. The results of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that the crisper packaging in combination with the 1-MCP treatment could effectively maintain the integrity and stability of the F. velutipes cellular structure and inhibit the emergence of plasmolysis to prevent cell membrane rupture. The transcription levels showed that the crisper packaging and the combination of the 1-MCP treatment and crisper packing could effectively affect the expression of genes for enzymes related to lignification and softening of F. velutipes. In conclusion, 1-MCP and PP crispers could delay the lignification and softening of F. velutipes during storage.

As a synthetic functional analog of salicylic acid, 2,6-dichloroisonicotinic acid (INA) is effective in inducing the host disease resistance of a plant against a pathogen. The effects of INA on controlling postharvest blue and green molds and anthracnose decay and defense-related enzymes on citrus fruits were investigated, and the ascorbic acid of naturally infected citrus flavedo was also measured. Results showed that 1.0 mmol L−1 INA treatments significantly reduced blue and green molds and anthracnose decay development on both wound-inoculated fruit and naturally-infected fruit compared with the control fruit. The treatment effectively enhanced the β-1,3-glucanase (GLU), chitinase (CHI), phenylalanine ammonia-lyase (PAL) and peroxidase (POD) activities and the polyphenol oxidase (PPO) in flavedo. The results presented here suggest that INA might be used as a chemical fungicide substitution to control postharvest diseases in citrus fruits.

Our goal was to evaluate how mechanical injury induced oleocellosis, and its discolouration and oxidative stress mechanism in Fengji Navel oranges (Citrus sinensis L. Osbeck) during previous storage. The results indicated that H2O2 content in mechanical treated fruit was higher than control. APX activity was higher than control during most of previous storage, but CAT, GR activities and ASA, GSH contents were lower than control, which showed GR activity and ASA, GSH contents might play an important rule in enhancing H2O2 to damage cell in mechanical treated fruit. Moreover, our study showed that chlorophyll content was enhanced, but total phenols content was not affected by mechanical during previous storage, which showed that discolouration was turning green but not browning at previous storage.

In order to learn effective methods for oleocellosis control, the induction of disease resistance and reactive oxygen species metabolism in valencia oranges by postahrvest polyamines treatment was investigated in this study. As showed in the result, polyamines and polyamine with hot water treatment had a significant effect on controlling oleocellosis during storage. Compared with control, MDA content in polyamine-treated fruit was rapidly decreased, but catalase and peroxidase activity had a sudden increase. Moreover, fruit in polyamines and polyamines with HWT treatment had a rapid increase in ASA-GSH anti-oxidation ability, and total phenols content in treated fruit also increased suddenly before 9 d, then followed by a sudden decline. Fruit in polyamines and polyamine with HWT treatment had a lower polyphenoloxidase (PPO) activity. Thus, polyamines may enhance antioxidation of citrus peel to improve disease resistance and decrease PPO activity to produce little rind spot during storage.