Effect of Polypropylene Film Packaging and Storage Temperature on Chemical Components and Quality Stability of Welsh Onion.

Abstract

Chemical components and quality of Welsh onion (Allium fistulosum L.) wrapped roughly or completely heat-sealed with orientated polypropylene (OPP) film were investigated during storage at 5 and 20°C. Concentrations of oxygen (O2) and carbon dioxide (CO2) in the roughly heat-sealed packages were the same as in air, whereas O2 concentration in the completely heat-sealed packages decreased to 2-3% at 20°C and to 4-5% at 5°C. Contents of reduced ascorbic acid (RAA) and chlorophyll in onion which was roughly sealed and stored at 20°C decreased, and withering of leaf tip occurred. This meant that the quality deteriorated severely. However, the contents of RAA and chlorophyll in Welsh onions which were sealed completely and stored at 20°C, and which were sealed roughly or completely and stored at 5°C, did not change or only slightly decreased. In Welsh onion sealed completely and stored at 20°C, off-odor was detected after 2 days and severely after 7 days and leaf tips began to wither after 7 days, suggesting that quality could be kept only for 4 days storage. In Welsh onion sealed completely and stored at 5°C, off-odors and withering of leaf tip was not observed for 9 days, indicating that quality marketability could be kept for that period.