Effect of non-conventional storage methods on external and internal egg qualities

Abstract

To know and identify the traditional practices and generate relevant information on egg storage methods, a survey work was conducted in the East Wollega Zone of Ethiopia. The survey was carried out with a stratified sampling technique and a structured questionnaire using a total of 315 households (225 from rural and 90 from urban owning chickens) were purposefully selected. Two experiments, of similar experimental materials, procedures and designs were conducted at different time of the year (May and August) to evaluate these traditional storage methods at Haramaya University poultry farm. A factorial experiment of 2 by 5 with completely randomized design using storage containers and storage time as treatment was used. The storage times were 4, 6, 8, 12 and 20 days. Five most common egg storage containers were identified in the rural and urban areas of East Wollega. These storage methods include cartons, polyethen bags, baskets, clay pots and teff grain. The result further indicated that depending on the availability of the storage materials in the locality, 87 percent of the urban households (n = 90) store eggs in cartons and polyethene bags in order of availability. Seventy nine percent of the rural households (n = 225) ranked teff as the most common storage materials used followed by the basket and clay pots. Among the quality parameters considered, weight loss (%) and daily weight loss (%) of eggs were highly affected (P < 0.001) by storage containers, durations and their interactions during both experiments. The maximum weight loss was observed after storage period of 16 days for all containers. Polythene bags storage maintained minimum weight loss Vs the baskets at all stages of storage duration. Only storage durations had significant effects (P < 0.05) on the egg shell thickness during experiment I. Inconsistent but significant effect of storage durations was observed on the shell weight during experiment I, and weights of yolk and albumen during experiment II. Storage containers during experiment I, and storage durations during experiment II showed significant effects on albumen height and haugh unit values. Except polythene bags which had higher albumen height and haugh unit values, the other containers did not show significant variations for both parameters. The effect of storage duration on these parameters was linear with increasing storage duration; and higher beyond the 16 days of storage. Thus, it was concluded that using polyethylene bags and 16 days of storage could give the best result to store eggs among the traditional methods compared in this experiment.

Keywords: Traditional Egg Storage; Changes in Egg Quality; Optimum Egg Storage Duration