Experiments were carried out to investigate the influence of different types of films with/without LCA (low-ethylene controlled atmosphere] conditioner on the quality of bagged lettuce (Lactuca sativa L. var. capitata L.) during the short-term storage.
Experiment 1: It has been shown that LCA conditioner was very effective in oxidation of ethylene, evolution of CO₂, and removal of O₂ in the film bag. Among 1, 3, 20, 30, AIS and SS films tested, film 20 was the most available for short-term storage of lettuce and suitable for maintaining optimal gas environments in film bag such as 0.05/0.5ppm (with/without LCA conditioner) in ethylene, 25/15% in CO₂, and 8/6% in O₂ at day 8. On the other hand, AIS and SS films made by Japan were found to be of no effect on the accumulation of COQ and removal of O₂ because of high permeability.
Experiment 2: CO₂ and O₂ concentrations- in the 20A, 20B (with LCA conditioner) and FH film bag stored at 4℃ and 20℃ was more influenced by the storage temperature than the effect of LCA conditioner. LCA conditioner was, therefore, not effective method to control a gas compositon under low temperature such as 4 c except a complete removal effect of ethyene. Lettuces kept in the different film bags were taken out and their postharvest qualities were compared. All the treatments (20A, 20B, and FH) with the film bags stored at 4℃ showed significantly higher values than contol without film bag in contents of chlorophyll and anthocyanin, and fresh weight but there were no significant differences between treatments. Vitamine C contents were higher in 20B and FH treatments than 20A and control. However, the qualities of all the treatments stored at 20℃ have not been determined because of rot during storage. Visual evaluation was good in order of 20B, FH, and 20A.
In conclusion, it was postulated that the combination of film bag with appropriate permeability, low temperature, and removal of ethylene would be the most effective method for the short term storage of lettuce.
|