The effect of a diet supplemented with sea-buckthorn pomace on the colour and viscosity of the egg yolk

Sea-buckthorn pomace is a very valuable product which contains not only important nutrients but also high-quality oils. The question addressed in the present study was to what extent the diet containing the sea-buckthorn pomace would affect the viscosity and colour of egg yolk measured in the CIELAB system. The feeding mixture for laying hens was supplemented with 20; 50 and 100 g.kg(-1) of sea-buckthorn pomace. As a result, colour indices of the egg yolk such as L*, a* and b* changed significantly (alpha = 0.01). The greatest relative enhancement was observed for indicator a* for the red colour. Visually, this corresponds to the more intense orange colour of the egg yolk. The addition of sea-buckthorn pomace to the diet for laying hens resulted in a larger increase in indicator Delta E* (CIE total colour difference) compared to the control group. Colour indicator hab is the only indicator whose value oscillated around that determined for the control group. The addition of sea-buckthorn pomace to the diet resulted in an increase in colour indices a*, b* and C*(ab). Indicator Delta E* also increased significantly with an increasing amount of sea-buckthorn pomace in a diet. Egg yolks were darker, had more intense red and yellow colours, and showed lower viscosity which are all features preferred by the consumer.