The Effect of Harvest Date and Packaging in Polyethylene Films on Apple Storage

Bassem Balkees
General Commission for Scientific Agricultural Research-
Lattakia Research Center
Damascus University, Faculty of Agriculture
2007

Abstract

This research was carried out during 2002-2004 At the General Commission for Scientific Agricultural Research in collaboration with Faculty of Agriculture, Damascus University. It aimed to study the effects of harvest date, packaging in polyethylene films and cold storage duration on the quality of apples (Malus domestica Bork. c vs. ‘Golden Delicious’ & ‘Starking Delicious’) cultivated in Thahr AlJabal area, Suweida province. The goal of this study was to reduce the weight natural loss in apples during storage and to maintain their quality.
Apples were harvested in common harvest period in the planting area on three successive dates with intervals of one week between each date and the next. The first harvest in the first season was on 24/9/2003 after 156 days of full blooming, which was used to choose the harvest date in the next season so that it was on 28/9/2006. After grading and sorting of the fruits, they were put in plastic boxes and packaged with low density polyethylene (LDPE) films of 40 ¼m thickness. Then they were stored at 0 oC in a storage unit in Damascus.
Readings were taken regularly on different parameters to know the effects of the factors mentioned above on the apples during their storage. We measured natural weight loss, fruit flesh firmness, total soluble solids, titrable acidity and starch index. ANOVA of the data was statistically performed using CoStat V6.024 and MsExcel, to determine the significance of differences between different treatments, and LSD was calculated to compare them.
We found that packaging in polyethylene films had a significant effect to reduce the apples weight loss for all harvest dates ore than a double) in the control for ‘Golden Delicious’ and ‘Starking Delicious’ respectively after 60 days. At the end of storage period (after 220 days) the weight losses reached 5.43 and 3.16% in packaged apples versus 1.94 and 1.46% in the control for ‘Golden Delicious’ and ‘Starking Delicious’ respectively.
The results showed a significant effect of the harvest date on the weight loss during storage. The weight loss decreased in ”Golden Delicious’ as harvest date was delayed, but there was some change in the fruits behavior when they were packaged as the highest weight loss happened in the third harvest date apples. In the early stages of storage the weight loss was lower in ‘Starking Delicious’ when harvest date was delayed, but it increased for third harvest date in the late stages, and this was more obvious in packaged apples. The high water loss caused shriveling in control apples and they lost their brightness, while packaged apples kept their shiny attractive appearance.
The harvest date affected significantly the different quality parameters of the apples, and the packaging had significant effect on some of them. In addition to that there was an interaction between these two factors that affected the studied parameters during storage.