Chapter 7 Eggs
Chapter 7 Eggs
Composition of eggs % Water Protein Fat CHO Whole 100 74.6 12.1 11.2 1.2 White 58 88.0 10.1 0.2 0.8 Yolk 31 48.0 16.4 32.9 2.0
Composition of eggs % Water Protein Fat CHO Whole 100 74.6 12.1 11.2 1.2 White 58 88.0 10.1 0.2 0.8 Yolk 31 48.0 16.4 32.9 2.0
Composition of Eggs - egg white (albumen) • Water (~88%) • CHO (~1%) −mainly glucose, may cause brown discoloration in dried eggs and hard cooked eggs (Millard reaction) • Fat (trace)
Composition of Eggs - egg white (albumen) • Water (~88%) • CHO (~1%) −mainly glucose, may cause brown discoloration in dried eggs and hard cooked eggs (Millard reaction) • Fat (trace)
Composition of Eggs - egg white (albumen) • Proteins (~11%), most are glycoproteins −Three primary proteins: − ovalbumin (54%) Structure of Baked Products ovotransferrin (12%), Binds metal, Discoloration ovomucoid (11%) Protease Inhibitor − ovomucin (1.5%): A Fibrous Protein, contributes to the thickness of the white (4 x more abundant than in yolk), contributes to the stability of egg white foam
Composition of Eggs - egg white (albumen) • Proteins (~11%), most are glycoproteins −Three primary proteins: − ovalbumin (54%) Structure of Baked Products ovotransferrin (12%), Binds metal, Discoloration ovomucoid (11%) Protease Inhibitor − ovomucin (1.5%): A Fibrous Protein, contributes to the thickness of the white (4 x more abundant than in yolk), contributes to the stability of egg white foam
Composition of Eggs - egg white (albumen) • Proteins (cont’n) •globulins (8%): including lysozyme, are important for foaming •lysozyme: ability to hydrolyze a polysaccharide in the cell wall of some bacteria to prevent bacterial spoilage • others: ovoinhibitor, ovoflavoprotein, ovomicroglobulin, avidin (binds biotin, but is heat sensitive)
Composition of Eggs - egg white (albumen) • Proteins (cont’n) •globulins (8%): including lysozyme, are important for foaming •lysozyme: ability to hydrolyze a polysaccharide in the cell wall of some bacteria to prevent bacterial spoilage • others: ovoinhibitor, ovoflavoprotein, ovomicroglobulin, avidin (binds biotin, but is heat sensitive)