Effect of different storage temperature on hypobaric storage quality of Pleurotus eryngii

Abstract: Taking Pleurotus eryngii as the material, the experiment was carried out. In the experiment, Pleurotus eryngii was packaged in 0.07 mm low-density polyethylene bag that was vacuumed to 0.06 MPa, and stored in 0, 2, 4, 6 and 8℃. The effects of different storage temperatures on postharvest physiology and quality of Pleurotus eryngii were studied under the condition of hypobaric storage. The results showed that Pleurotus eryngii stored at 2 and 4℃ preferably maintained the activities of superoxide dismutase (SOD) (P<0.01) and catalase (CAT) (P<0.05), maintained a higher scavenging capacity of reactive oxygen free radical, inhibited effectively the increase of malondialdehyde (MDA) (P<0.01), reduced the respiration rate (P<0.01) and delayed aging process. So, it could better maintain the hardness, springiness, cohesiveness and chewiness, and inhibit effectively the activity of polyphenol oxidase (PPO) (P<0.01), delay the browning degree and preferably maintain the color (P<0.01). For Pleurotus eryngii stored at 6 and 8℃, the activities of SOD and CAT changed greatly, and especially decreased rapidly in the middle-late storage period, but the activity of PPO was higher. Therefore, its scavenging activity of reactive oxygen species was weakened, large amounts of MDA were produced, and the respiration rate was increased. And the speeds of aging and browning of Pleurotus eryngii were accelerated, while texture quality was lowered. These results showed that 6 and 8℃ were not suitable for the storage of Pleurotus eryngii under the hypobaric condition. However, the changes of postharvest physiology and quality of pleurotus eryngii stored at 0℃ were special, for the respiration rate of pleurotus eryngii fruit body stored at 0℃ was better inhibited, and the activity of SOD was maintained effectively, but the activity of CAT decreased rapidly when stored at 0℃. When pleurotus eryngii was stored at 0℃, the texture quality did not be kept well, and the activity of PPO, the value of color difference and the content of MDA were higher than that stored at 2 and 4℃; the content of MDA was even higher than that stored at 6 and 8℃ in the later storage period. So it can be inferred that the changes of postharvest physiology and quality of pleurotus eryngii stored at 0℃ were abnormal. It may be the results of the slight chilling injury. The dormant cause is worth further studying. In conclusion, the appropriate storage temperature is from 2 to 4℃ for Pleurotus eryngii which is packaged in 0.07 mm low-density polyethylene bag that is vacuumed to 0.06 MPa. In this storage temperature, the fresh-keeping effects of Pleurotus eryngii are good. The storage method can effectively delay the ripening and senescence process of Pleurotus eryngii, keep the texture quality better, and extend the storage period of Pleurotus eryngii. In addition, not only this storage method has a good effect of storage, but also its cost is low and the operation is convenient. The hypobaric storage technology is flexible to the application to postharvest preservation of Pleurotus eryngii, and it avoids the high cost of the construction and operation of hypobaric cold storage. Therefore, this method is an effective storage method to reduce the loss of postharvest storage, and improve economic benefit of Pleurotus eryngii. This method has a certain popularization value and application prospect.