Effect of modified atmosphere packaging (MAP) on control of shrivel and overall quality of 'Laetitia' plums.
Crouch, I. J.;
Acta Horticulturae Year: 1998 Issue: No. 464 Pages: 393-396 Ref: 4 ref.
1998
บทคัดย่อ
Laetitia plums exhibit severe shrivel after storage and no significant reduction in shrivel between fruits packed with paper wrappers and fruits packed without them has been detected in previous trials. As an alternative to wrappers, fruits were packed in a selection of different bags including ones made from P-Plus film (PA30 (most modified atmosphere), PA60, PA90, PA120, PA160, PA200, PA220 and PA240 (least modified atmosphere)). By controlling permeability, the O2, CO2 and moisture levels were adjusted to slow down the respiration rate, so creating a natural equilibrium modified atmosphere in the bags. The effect of the bags on fruits packed in export cartons and plastic punnets was examined after 7 weeks of storage under a dual temperature regime (10 days at -0.5 deg C, 18 days at 7.5 deg C, 14 days at -0.5 deg C and 7 days at 10 deg C). After storage, bagged fruits packed in cartons had <6% shrivel compared to >60% in unbagged fruits and 77% in fruits packed with the paper wrapper. The shri
vel levels on bagged fruits packed in plastic punnets were generally <3% compared to an incidence of almost 50% on unbagged punnet-packed fruits. Fruits packed in punnets with and without bags experienced a mass loss of 0.6% and 5.9%, respectively. The maturity of bagged fruits was not as advanced as fruits stored without bags. Bagged fruits were firmer, had lower levels of total soluble solids, and exhibited less colour development after 7 weeks of storage. Levels of fruit decay exceeded the 1% tolerance limit in several of the bag types. No internal disorders or tainting were found in any of the plastic punnet bagged treatments above PA120. Below PA120, the highly modified atmosphere in the bags resulted in a high incidence of gel breakdown. The highest levels of gel breakdown in the bagged cartons (4.2%) occurred in the PA160 bags. The results suggest that MA packaging can be used to prevent shrivel in plums, but that further research must be done to quantify any adverse effects on fruit quality, and the
effect of the packaging must be evaluated using fruits harvested at different maturities.