EFFECTS OF ENVIRONMENTAL GASES ON THE SHELF-LIFE OF JAPANESE APRICOT

The storage method under a perfectly controlled atmosphere (PCA), in which not only O2, CO2 and relative humidity (RH) were controlled but also metabolic volatiles such as ethylene, acetaldehyde and others were automatically removed, was applied to mature-green mume fruit (Japanese apricot cv. Ohshuku). The fruits were stored under conditions of 2 approximately 3 % O2 and 3%, 8%, 13% and 18% CO2 at 20-degrees-C and 100% RH, and the effects of environmental gases on the shelf-life were investigated and compared with seal-packaging method (using both linear low density polyethylene film with 30-mu-m thickness and an ethylene-acetaldehyde removing agent). (1) C2H4 evolution was detected at the 19th day for seal-packaging and at the 15th, 19th, 23rd and 23rd day for PCA storage of 3%, 8%, 13% and 18% CO2, respectively, while it was detected at the 3rd day in air. (2) Surface yellowing and flesh softening were delayed remarkably at higher CO2 levels than at lower levels, (3) Pitting like injury occurred in the fruits stored in air, and internal browning which was caused by low O2 (< 2%) or high acetaldehyde (> 90 ppm) occurred in seal-packaged fruits. No injury was observed up to the 23rd day during PCA storage of 3 approximately 13% CO2, while two types of CO2 injury were caused at 18% CO2. (4) Adding two days for distribution, the shelf-life were 12 days for seal-packaging and 15, 15, 19 and 12 days for PCA storage of 3%, 8%, 13% and 18% CO2, respectively.