Genetic effect on free amino acid contents of egg yolk and albumen using five different chicken genotypes under floor rearing system

Abstract

Chicken eggs play an important role as food resources in the world. Although genetic effects on yolk and albumen contents have been reported, the number of chicken genotypes analyzed so far is still limited. To investigate the effect of genetic background on 10 egg traits, 19 yolk amino acid traits, and 19 albumen amino acid traits, we evaluated a total of 58 eggs from five genotypes: two Japanese indigenous breeds (Ukokkei and Nagoya) and three hybrids (Araucana cross, Kurohisui, and Boris Brown) under a floor rearing system. One-way ANOVA revealed significant effects of genotype on 10 egg traits, 8 yolk amino acids (Asp, Glu, Ser, Gly, Thr, Tyr, Cys, and Leu), and 11 albumen amino acids (Asp, Glu, Asn, Ser, Gln, His, Ala, Tyr, Trp, Phe, and Ile) contents. Moderate to strong positive phenotypic correlations among traits within each trait category (size and weight traits, yolk amino acid traits, and albumen amino acid traits), whereas there were basically no or weak correlations among the trait categories. However, a unique feature was found in the Araucana cross indicating moderate positive correlations of amino acids between yolk and albumen. These results suggest that genetic factors can modify not only the size and weight of the egg and eggshell color but also yolk and albumen free amino acids contents.

The Effect of L-Glutamine on Basal Albumen and Yolk Indices, and Albumen Amino Acids Composition

“…Our study showed that the most abundant amino acids in the albumen of the eggs were aspartic acid, serine, glutamic acid, valine, leucine, and lysine, while histidine was the most limiting amino acid. These results are in agreement with other reports, where the same amino acids were in the abundance, irrespective of the source of eggs [ 6 ]. The Gln supplementation to laying hens in the present study resulted in an increase in asparagine, proline, phenylalanine, tyrosine, and tryptophan content.…”

“…More frequently the consumers’ preference relating pro-health properties, e.g., antioxidants, lipid content, have been taken into consideration [ 42 ]. However, in the past few years the relationship between eggs amino acids and taste (sweetness, sourness, saltiness, bitterness, and umami) has been studied [ 6 ]. Among these amino acids are essential and non-essential.…”

“…Egg albumen consists of about 10% of protein, with many functionally important proteins, like ovalbumin (54%), ovotransferrin (12%), ovomucoid (11%), lysozyme (3.5%), and ovomucin (3.5%) [ 4 ]. Eggs have been identified as the lowest-cost source for proteins among all protein sources in the USA [ 5 ], and very useful sources of high-quality protein in developed and developing countries alike, with high biological value and digestibility [ 6 ]. Taking into account the increasing demand for proteins in the food industry related to both increasing population growth as well as increasing interest in egg components acting as nutraceuticals such antioxidant properties, antimicrobial activities, immunomodulatory, and anticancer important for a healthy lifestyle, it is expected that protein content and amino acids profile will become the components of eggs that could play critical roles in egg selection, especially that egg taste can be changed by altered contents of free amino acids [ 7 , 8 , 9 ].…”

Rosehip (Rosa canina L.) Meal as a Natural Antioxidant on Lipid and Protein Quality and Shelf-Life of Polyunsaturated Fatty Acids Enriched Eggs

“…For the AAA aspartic acid, lysine, methionine, and tyrosine were considered the main contributor to the antioxidant properties of eggs, from which RF2 had the highest cumulated value compared with RF0. Cysteine, methionine, tyrosine, and histidine were reported as being relatively easily oxidized [ 37 ], however, the antioxidant potential of rosehip meal, improves their antioxidant properties to prevent protein oxidation. The EAA/TAA ratio, cysteine/SAA ratio, as well as total SAA, were significantly higher in RF1 and RF2, compared with RF0 eggs, showing high variability for the determined AA.…”

Sensory Characteristics, Nutritional Composition, and Quality of Eggs from Different Chickens

“…Likewise, single nucleotide polymorphism of fatty acid desaturase1 could enhance egg flavor intensity and continuity, while negatively correlated with n-6/n-3 ratios [34]. Similarly, free amino acid profiles of Araucana eggs were significantly varied in egg flavor as compared to Ukokkei, Nagoya, Kurohisui, and Boris Brown egg flavors [35]. The hardboiled egg flavor differences could be attributed to variations in dry matter contents of eggs in laying hens [36].…”