Composition of Eggs egg yolk Proteins (16. 4%) plasma(78%0: livetin LDL (protein content N 10%0) granular fraction phosvitin(16%0 carrier of Fe), lipovitellins(70%0 )& LDl (12%) Water(48%0
Composition of Eggs - egg yolk • Proteins (16.4%): • plasma (78%): livetin & LDL (protein content ~ 10%) • granular fraction: phosvitin (16%, carrier of Fe), lipovitellins (70%) & LDL (12%) • Water (48%)
Composition of Eggs egg yolk o Lipids (32 to 34%) triglycerol(66%0) phospholipid(28%)including lecithin (has remarkable emulsifying ability cholesterol (3%, or 250 mg) The color of yolk depends on the presence of carotenoids xanthophylls not carotene (Lutein and zeaxanthin
Composition of Eggs - egg yolk •Lipids (32 to 34%) − triglycerol (66%) − phospholipid (28%) including lecithin − (has remarkable emulsifying ability) − cholesterol (3%, or 250 mg) •The color of yolk depends on the presence of carotenoids. • xanthophylls not carotene (Lutein and zeaxanthin)
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Egg quality Commercial grading of eggs according to the usda standards External quality: shell characteristics, shape, soundness, cleanliness, color Interior quality size of the air cell, firmness of the white the yolk (distinct or flattened during aging) Evaluated by candling
Egg Quality • Commercial grading of eggs according to the USDA standards • External quality: shell characteristics, shape, soundness, cleanliness, & color • Interior quality: size of the air cell, firmness of the white, & the yolk (distinct or flattened during aging) • Evaluated by candling
Egg quality during storage The size of the air cell increases water evaporates from the egg through shell The egg white becomes thinner ovomucin undergoes degradation pH of white increases (from N 8 to v 9) due to the loss of Co2 through the pores
Egg quality during storage • The size of the air cell increases − water evaporates from the egg through shell • The egg white becomes thinner − ovomucin undergoes degradation • pH of white increases (from ~ 8 to ~9) − due to the loss of CO2 through the pores