ISHS Acta Horticulturae 464: International Postharvest Science Conference Postharvest 96
EFFECT OF MODIFIED ATMOSPHERE PACKAGING (MAP) ON CONTROL OF SHRIVEL AND OVERALL QUALITY OF ‘LAETITIA’ PLUMS |
| Author: | I.J. Crouch |
| Abstract:
‘Laetitia’ plums exhibit severe shrivel after storage. To reduce its incidence, a paper wrapper is included in export cartons to increase relative humidity and reduce water loss by the fruit. However we found no significant reduction in shrivel between ‘Laetitia’ fruit packed with the paper wrappers and fruit packed without them. As an alternative to wrappers, fruit was 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 are adjusted to slow down the respiration rate, so creating a natural equilibrium modified atmosphere (EMA) in the bags. The effect of the bags on fruit packed in export cartons and plastic punnets was examined. Bagged fruit packed in cartons had <6% shrivel compared to >60% in unbagged fruit and 77% in fruit packed with the paper wrapper. The shrivel levels on fruit packed in plastic punnets never exceeded 5% compared to an incidence of almost 50% on unbagged punnet packed fruit. Fruit packed with and without bags experienced a mass loss of 0.6% and 5.9%, respectively. The maturity of bagged fruit was not as advanced as fruit stored without bags. Bagged fruit was 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 bag 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. These 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. The effect of the packaging must now be evaluated using fruit harvested at different maturities. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
