Implications of the storage conditions and production system on the physical properties of eggs: a multivariate data analysis study

Abstract

Summary The objective of this study was to apply multivariate data analytical methods to evaluate the effect of both storage conditions (cold and room temperature) and production systems (cage and free range) on the physical properties of chicken eggs produced under tropical conditions. The results of this study indicated that most of the physical quality parameters (Haugh units, egg weight, albumin height, yolk colour, shell breaking and shell thickness) measured in the egg samples stored at room temperature (RT) were lower compared with egg samples stored in cold room (CT) conditions. The weight loss rate (WLR) was higher in the egg samples from RT compared with CT conditions. Both egg samples from either CT storage conditions or FR production system had the best quality parameters (high Haugh units, heavy egg weights and low WLR). The highest classification rate using linear discriminant analysis was obtained for the prediction of systems of production where egg samples from cage (C) and FR were 83% and 80% correctly classified. However, the classification of weeks of storage provides with intermediate classification results based on the physical parameters measured where 75% and 72% of the samples were correctly classified as stored in CT or RT storage conditions, respectively. The utilisation of multivariate data analysis allowed for the analysis of all the variables at the time without the need to isolate effects such as birds age, housing systems or by the solely interpretation of a single parameter.