Effects of Dietary Rapeseed (Brassica napus), Hemp (Cannabis sativa) and Camelina (Camelina sativa) Seed Cakes Supplementation on Yolk and Albumen Colour and Nutritional Value of Yolk Lipids in Estonian Quail Eggs

SIMPLE SUMMARY: Despite the regional preferences for quail eggs and meat, and the main production being found in Asian countries, the popularity of quail raising has increased and their production has been introduced in many other countries, including the Baltics. A wide distribution around the world encouraged genetic divergence among Japanese quail populations, the formation of different breeds and lines as well as their research. The Estonian quail, a breed developed in Estonia, has also spread in Lithuania. This study aimed to evaluate yolk and albumen colour, as well as the nutritional value of yolk lipids in Estonian quail eggs using diets supplemented with cakes from local oil corns (rapeseed, hemp and camelina seeds). The diet affected the colour as well as the cholesterol content and fatty acid composition of the yolk. All quail groups demonstrated the high lightness (L*) and yellowness (b*) of the yolk; however, the negative value of parameter a*, instead of being red, showed a greenish colour. The highest proportions of total saturated (SFAs) and polyunsaturated (PUFAs) fatty acids as well as the lowest monounsaturated fatty acids (MUFAs) were found in the yolk lipids of the quail which was fed a mixture supplemented with hemp cake. The lowest and most favourable n-6/n-3 ratio was demonstrated by the quail fed the diet supplemented with camelina. However, the lowest yolk cholesterol content was demonstrated by the quail fed the diet supplemented with rapeseed cake. ABSTRACT: The aim of this study was to investigate the effects of supplementing commercial diets with rapeseed, hempseed and camelina seed cakes on the yolk and albumen colour and nutritional value of yolk lipids in Estonian quail eggs. A total of 585 eggs were used to evaluate egg weight, yolk and albumen pH and colour, proximate yolk composition, cholesterol content and fatty acid composition in the yolk lipids of three Estonian quail groups each fed a diet supplemented with 10% rapeseed, hemp or camelina seed cakes. The higher (p < 0.01 and p < 0.05, respectively) lightness (L*) of the yolk was detected in the group of quail fed the diet supplemented with rapeseed and camelina cakes compared to the hempseed addition. Meanwhile, the albumen lightness in the rapeseed group was higher (p < 0.01) in comparison to the camelina group. A lower (p < 0.001) yolk negative a* value was estimated in the hemp group than in the groups fed rapeseed and camelina seed cake supplements, while the rapeseed group demonstrated lower (p < 0.001) albumen yellowness (b*) and colour saturation (C) in comparison to the other groups. The highest and lowest proportions of total saturated (SFAs)and monounsaturated (MUFAs) fatty acids, respectively, were found in the yolk lipids of quails fed a mixture supplemented by hemp cake. A higher (p < 0.05) proportion of polyunsaturated fatty acids (PUFAs) was only found in the hemp group compared to the camelina group. The highest and lowest (p < 0.001) n-6/n-3 PUFA ratios were found in the yolk lipids of quail receiving mixtures supplemented with rapeseed and camelina cakes, respectively. The yolk of the quail from the rapeseed group showed more favourable lower and higher (p < 0.01 and p < 0.05, respectively) atherogenic index (AI) and hypocholesterolemic/hypercholesterolemic (h/H) ratio compared to the hemp and camelina groups. The lower yolk cholesterol content was found in the eggs of the quail fed the diet supplemented with rapeseed cake compared to the eggs of the quail which were fed the diets containing more n-3 PUFAs from the addition of hemp and camelina cakes (p < 0.05 and p < 0.01, respectively).