Potential of modified atmosphere packaging for storage of ‘Dhakki’ dates

The date palm (Phoenix dactylifera L.) imparts close and everlasting association with mankind, and is a legend for the Arabic world. Since date palm is an important tree of arid and tropical regions a large area of Pakistan is under date cultivation ranking the country at 5^th position world over. The ‘Dhakki’ cultivar of Dera Ismail Khan (KPK, Pakistan) has extra-large size (5-6×3-4 cm²), very high pulp (96%) to small pit ratio and delicious taste, and hence it is considered one of the best cultivars worldwide. However, coincidence of ripening season with monsoon and adoption of traditional technology are a few major factors responsible for excessive wastage and quality degradation, and are the basis for low return. The ‘tamar’ dates intended for marketing and storage for being nutritious are prone to deterioration micro-biologically and biochemically. The use of modified atmosphere packaging (MAP) is currently underway extending shelf-life of fresh and processed food commodities. The atmosphere surrounding the product is desirably modified by passive MAP technique developing naturally a desired atmosphere through selective film packaging. The MAP is responsible for reduced respiration and ethylene production, and quality preservation. The present study was undertaken to investigate the response of MAP to ‘Dhakki’ date on storage at 40°C. The cured ‘Dhakki’ date adjusted to 0.52, 0.62 and 0.75 water activity was packed under cellophane, polyethylene and laminated film pouches and changes in physico-chemical and organoleptic quality parameters were evaluated. The quality deterioration appeared a function of both water activity and type of gaseous atmosphere produced under the package. Samples stored at 0.75 aW under cellophane rapidly deteriorated largely by slime formation, and that with 0.62 aW under laminated film maintained natural characteristic color, flavour and freshness of samples during storage. In order to extend shelf life of high quality product ‘Dhakki’ dates adjusted to 0.62 aW require proper MAP packaging for storage.