Age-related changes in egg yolk composition between conventional and organic table eggs

Yasin Baykalir,Okkes Yilmaz,Ulku Gulcihan Simsek

doi:10.23986/afsci.91704

Abstract

The aim of this study was to investigate fatty acids, fat-soluble vitamins, malondialdehyde and cholesterol in conventional and organic eggs obtained from hens of different ages (30 and 60 weeks). A total of 360 egg yolks were used in this study. Polyunsaturated fatty acid, omega-3, and omega-6 levels were higher in the organic eggs from the 30-week-old hens. The monounsaturated fatty acid level was higher in the conventional eggs but was the same between the two age groups. Cholesterol and vitamin A levels were not influenced by either the rearing system or the age of the hens. The malondialdehyde, vitamin D2, and vitamin K2 were higher in the organic eggs; however, vitamin E was higher in the conventional eggs. The results showed that the rearing system and age, as well as the diet, had an impact on the composition of the egg. Total levels of polyunsaturated fatty acid, omega-3, and omega-6 are higher in organic eggs produced by younger hens.

Highlights

Hen eggs are a good-quality and inexpensive food source with a moderate amount of calories (Miranda et al 2015)
It has been suggested that a high level of polyunsaturated fatty acids (PUFAs) in the hen diet causes a decrease in monounsaturated fatty acids (MUFAs) content in the egg yolk (Shahid et al 2015); in this study, total PUFA was decreased in eggs from older hens, which suggests that the hen’s bodily functions are reduced with age (Barzilai et al 2012)
The results of the present study showed that PUFA, n-3, and n-6 were higher in the organic table eggs; the organic eggs were more susceptible to oxidative deterioration because of their high levels of PUFA

Summary

Introduction

Hen eggs are a good-quality and inexpensive food source with a moderate amount of calories (Miranda et al 2015). PUFAs have important roles in sustaining physiological conditions, such as protecting cardiovascular and nervous systems Some chronic diseases, such as cardiovascular, diabetes, cancer, obesity, autoimmune, rheumatoid arthritis, asthma, and depression are related to the unbalanced intake of n-6 and n-3, especially when the amount of n-6>n-3 (Ristić-Medić et al 2013). The health benefits of fatty acids have led to widespread research on fatty acid composition in animal products, leading to several attempts to enrich the n-3 content in animal products (Woods and Fearon 2009). These attempts are most common in the poultry industry, especially in egg production (Rymer and Givens 2005).

Objectives

Methods

Discussion

Conclusion