TIPIFICACIÓN DE LA CALIDAD DEL HUEVO DE GALLINA ECOLÓGICO Y CONVENCIONAL.

Abstract

[EN] Egg is a frequently consumed food in Spain, as it is a basic component of theMediterranean diet. Egg quality is defined by its internal and external characteristics, as well as itsnutritional composition. In conventional farming systems, light intensity, temperature and ventilation ofthe farm are controlled. Within conventional farming system, egg-laying hens can beclassified according to their husbandry in cage hen, floor hens, and free-range hens.Organic farming is a regulated farming system which allows hens access to outside runs. The main objective of the present work is to categorise the egg quality of hens from organicand conventional farming using different quality parameters. Additionally, the effect ofthe type and age of the hen is evaluated in egg quality parameters. Twenty series of conventional eggs and 15 of organic eggs, coming fromAndalusia and Valencian Community, are analysed. Each series is composed by a meanof 18 eggs which are identified and whose external quality parameters ,internal quality parameters and nutritional parameters. Organic hens produce eggs with less weight, less rounded, with a higherdeposition rate, shell percentage and yolk content. The shell colour and its thickness arenot influenced by the husbandry system. The major fraction of crude protein in feed forhens of conventional systems influences the internal quality parameters, producing eggswith higher values of Haugh units, total albumen and a higher yolk shape index. From a nutritional point of view, the eggs obtainedfrom conventional systems show higher protein, carotenoid and fat contents, being fattyacids, both saturated and unsaturated, predominant in these eggs. Organic animal feed formulations and free diet are responsible for organic hens laying eggs with higher proportion of unsaturated fatty acids and a lower concentration of carotenoids. The hen type influences significantly in external, internal and nutritional qualityparameters except in the form index, dens albumen, and moisture and ashes contents.Aged hens lay eggs with less intense shell colour, worse albumen and yolk quality and less protein and carotenoid content. The quality parameters alow to classify eggs in different categories. A firstgroup formed by eggs having a shell color and an index of moderate form, which isoppositely correspond to the eggs with increased shell thickness, shell percentage and rateof deposition of the shell, where most include eggs conventional production. A secondgroup characterized by eggs showing a moderate egg yolk content as opposed to theparameters that define the quality of the albumen and color intensity of the yolk. A thirdgroup of eggs that are defined by high ash content that relate to a higher proportion ofpolyunsaturated fatty acids in opposition to the highest concentrations of carotenoids, fat percentage, percentage of saturated and monounsaturated fatty acids. Eggs from organic production are included in the second and in the third group.; [ES] El huevo es un alimento que en Espana se consume de forma muy…