Quality Analysis of Welsh Onion (Allium fistulosum L.) as Influenced by Storage Temperature and Harvesting Period

Abstract

Quality attributes of welsh onion (Allium fistulosum L.) as affected by harvest timing (November, December 2006 and January 2007) and storage temperature (5, 10 and 20 o C) were investigated in terms of respiration rate, weight loss, decay rate, color, hardness, sensory quality. A higher respiration rate was found when welsh onions were harvested later and storage temperature was higher. A smaller weight loss was observed in welsh onions that were harvested in November and stored at temperature of 5 o C, demonstrating a 9.35% reduction. In other words, there were a minimum difference of 2.15% and a maximum difference of 9.92% between the weight loss in test samples harvested in November and those of test samples harvested in other months. The decay rate was higher in welsh onions harvested in January. The degree of color was more stable in test samples kept at temperature of 5 o C than those kept at higher temperature (10 and 20 o C). There were, however, no significant differences in color changes among test samples harvested at different times of the year. Thus color change is closely associated with temperature. Also, welsh onions were harvested in November and stored at temperature of 5 o C showed a good sensory quality.