Effect of Drying Methods and Packaging on the Nutritional Values of Onions (Allium cepa L.) Bulbs

This research work was designed to give an insight on physiochemical properties of Allium cepa. The purpose of this study was to determine the effects of three drying methods on the physiochemical properties of onion bulbs and to determine the effective packaging material on the physiochemical properties of onion. Freshly harvested onion bulbs at a fully matured stage and fully ripe was purchased from a commercial farm at Locco farms from Song LGA of Adamawa State, Nigeria. The experiment consists of six treatments which include oven drying plastic container, oven drying polythene bags, sun drying plastic container, sun drying polythene bags, shade drying plastic container and shade drying polythene bags. The experiment was replicated three (3) times and data was collected on parameters such as color, bulk density, fat, carbohydrate and, fiber. The various drying methods used were capable of preserving the nutrients in A. Cepa without total loss of any nutrient. Shade dried and oven dried samples were found to be more nutritive, on the other hand, oven drying and sun drying were faster in drying than the shade drying method. Oven drying was more cost effective and gave the lowest moisture content in this study, suggesting higher capacity to prevent microbial growth and decay in the dried samples, thus confers a greater increase in shelf-life on the dried samples. On the other hand, plastic container packaging was found to be better in terms of maintaining physical and chemical properties of the dried samples followed, by polythene bags. Further study should be carried out on the factors that affect the storability of onion bulbs in both dried and fresh samples.