Abstract:

A new method to store kiwifruit were applied and the physiochemical changes of kiwifruit during storage were studied. In a cold storage house, about 5t kiwifruit was sealed in each of polyethylene tents. There were two sleeves, from which gas could move in or out, at the opposite ends of every tent. A carbon molecular sieve nitrogen generator (CMSNG) was used to produce nitrogen from air, the nitrogen was piped into the tent through the in-sleeve, and the original gas in the tent was removed out through the out-sleeve. When the original gas in the tent exchanged completely by the nitrogen, the tent was sealed. Several days later, when the oxygen in the tents reduced to the lower limit or the carbon dioxide accumulated to the upper limit because of the respiration of kiwifruit, the tents were refilled with nitrogen from CMSNG as before to adjust the gas composition. The above operations were carried out regularly.The results showed that kiwifruit in the polyethylene tents has lower activities of EFE, amylase and polygalacturonase (PG) than the fruit in cold storage, so that the ethylene forming was inhibited, the rate of decomposition of starch and pectin substances was reduced, therefore the storage life was prolonged. In our experiments, when the kiwifruit was stored for 8 months in polyethylene tents, the rate of sound fruit was 92.3%~94.5%, but only 44% in cold storage in 5 months.Polyethylene tens have several virtues: (1)The gas composition was adjusted quickly as one tent with kiwifruit was piled up, (2)Each of tents in the storage house was a independent unit, kiwifruit in one tent was transported out of the storage house conveniently in need of commerce not to effect other tents, (3)The gas only inside of the tents was low in oxygen and high in carbon dioxide, the outside of the tents was of nomal atmosphere, so the changes of kiwifruit in the storage house could be check safely and easyly at any time, etc. Therefore the polyethylene tents storage was a suitable storage technique for kiwifruit preservation.

Key words: Kiwifruit, Polyethylene tent, Ethylene forming enzyme (EFE), Amylase, Polygalacturonase(PG)