Quality and physiological responses of Fuji apple to modified atmosphere packaging during cold storage

Abstract: Modified atmosphere packaging (MAP) with polyolefin bags made of modified polyvinyl chloride (mPVC), micro-perforated polyethylene (mpPE), modified polyethylene (mPE), plastic film mulch (control-1), and polyvinyl chloride with holes (control-2) were evaluated for their ability to preserve quality of Fuji apple during storage at 0 to 1^oC. The results showed that atmosphere in mPVC bag was adjusted to 2.73%~2.38% CO₂ and 15.70%~18.13% O₂ while in mpPE, mPE and control-1 bag CO₂ levels were elevated and O₂ level declined to 0.10-0.72%, 20.53~20.9%, respectively. In mPE bag, fruits recorded significantly less weight loss than other packagings throughout the storage, while fruit in mPVC, fresh weight loss was same as in control-1. The overall fruit quality of flesh firmness (FFF), soluble solid content (SSC) and ascorbic acid remained at almost the same level in each packaging during the first 40 days of storage, and changed thereafter. Control-1 resulted in significantly lower FFF than other packagings till day 220 and SSC showed the same trend as in control-2. Respiration rate of fruit in mPVC, control-1 and control-2 peaked on day 220 and those in mpPE and mPE peaked on day 240. Ethylene production of fruit in each packaging increased since day 40 and peaked on day 80 for mPE and control-1, day 100 for mpPE and control-2, on day 120 for mPVC. A second peak for mPE appeared on day 120. Each packaging resulted a dramatic increase and drop of SOD activity in fruit in the first 40 days. After about 220 days of storage, superficial scald and core browning occurred on fruit in mpPE, mPE, control-1, control-2 by 2.4-6.0% and 1.2-1.6%, 6.3-7.9% and 15.8-17.3%, 0-1.6% and 4.4-4.6%, 15.4-16.1% and 3.2-4.5%, respectively while no such incidence was observed in mPVC. Decay and disorder developed faster when storage duration increased.