Dairy Chemistry And Biochemistry

Table 8.1 Indigenous enzymes of significance to milk

Enzyme Reaction Importance

Lipase

Proteinase (plasmin)

Catalase

Lysozyme

Xanthine oxidase

Sulphydryl oxidase

Superoxide dismutase

Lactoperoxidase

Alkaline phosphomonoesterase

Acid phosphomonoesterase

Triglycerides + H,O 4 fatty acids +partial

Hydrolysis of peptide bonds, particularly

2H,O, + 0, + 2H,O

Hydrolysis of mucopolysaccharides

Aldehyde+H,O+O, + Acid+H,O,

2RSH + 0, + RSSR + H,O,

20;+2H+ 4 H,O,+O,

H,O,+AH, +2H,O+A

glycerides +glycerol

in bcasein

Hydrolysis of phosphoric acid esters

Hydrolysis of phosphoric acid esters

Off flavours in milk;

Reduced storage stability of UHT products;

Index of mastitis; pro-oxidant

Bacteriocidal agent

Pro-oxidant; cheese ripening

Amelioration of cooked flavour

Antioxidant

Index of pasteurization;

flavour development in Blue cheese

chccse ripening

bacteriocidal agent;

index of mastitis;

pro-oxidant

Index of pasteurization

Reduce heat stability of milk;

cheese ripening