Inoculation and Milk Ripening The basis of cheesemaking relies on the fermentation of lactose by lactic acid bacteria(LAB).LAB produce lactic acid which lowers the pH and in turn assists goegeo2e2aeR2TABopa also produce growth fa ors wh ich encourages the growth of non- 3,and and prot essary ng ct and starter cultures ca ogy section After innoculation with the starter culture the milk is held for 45 to 60 min at 25 to 30°Cto sure the bacteria are active ing and have de veloped acidity.This Milk Coagulation Coagulation is essentially the formation of a gel by destabilizing the casein micelles causing them to aggregate and form a network which partially immobilizes the water and traps the fat globules in the newly formed matrix.This may be accomplished with: atment heat-acid treatmen Enzymes Chymosin,or rennet,is most often used for enzyme coagulation Acid Tre of the milk results in casein micelle destabili an renr curd e to the los s of calcium on can be ch ed n with the ure,or art with the che and Cr d coagulate cheeses may ine阴 ottag Heat-Acid Treatment Heat cause on of t .With the whey s.The denatured proteins then interact -789 lation 90%of p ed.E mp made by this method include Paneer.Ricotta and Queso Blanco. Curd Treatment After the milk has gel has been allowed to reach the desired firmness,it is carefully cut into small pieces with knife blades or wires.This shortens the distance and increases the available area for whey to be released.The curd pieces immediately begin to shrink and expel the greenish liquid called whey.This syneresis process is further driven by a cooking stage.The increase in temperature causes the protein matrix to shrink due to increased hydrophobic interactions,and also increases the rate Inoculation and Milk Ripening The basis of cheesemaking relies on the fermentation of lactose by lactic acid bacteria (LAB). LAB produce lactic acid which lowers the pH and in turn assists coagulation, promotes syneresis, helps prevent spoilage and pathogenic bacteria from growing, contributes to cheese texture, flavour and keeping quality. LAB also produce growth factors which encourages the growth of non-starter organisms, and provides lipases and proteases necessary for flavour development during curing. Further information on LAB and starter cultures can be found in the microbiology section. After innoculation with the starter culture, the milk is held for 45 to 60 min at 25 to 30° C to ensure the bacteria are active, growing and have developed acidity. This stage is called ripening the milk and is done prior to renneting. Milk Coagulation Coagulation is essentially the formation of a gel by destabilizing the casein micelles causing them to aggregate and form a network which partially immobilizes the water and traps the fat globules in the newly formed matrix. This may be accomplished with: • enzymes • acid treatment • heat-acid treatment Enzymes Chymosin, or rennet, is most often used for enzyme coagulation. Acid Treatment Lowering the pH of the milk results in casein micelle destabilization or aggregation. Acid curd is more fragile than rennet curd due to the loss of calcium. Acid coagulation can be achieved naturally with the starter culture, or artificially with the addition of gluconodeltalactone. Acid coagulated fresh cheeses may include Cottage cheese, Quark, and Cream cheese. Heat-Acid Treatment Heat causes denaturation of the whey proteins. The denatured proteins then interact with the caseins. With the addition of acid, the caseins precipitate with the whey proteins. In rennet coagulation, only 76-78% of the protein is recovered, while in heat-acid coagulation, 90% of protein can be recovered. Examples of cheeses made by this method include Paneer, Ricotta and Queso Blanco. Curd Treatment After the milk has gel has been allowed to reach the desired firmness, it is carefully cut into small pieces with knife blades or wires. This shortens the distance and increases the available area for whey to be released. The curd pieces immediately begin to shrink and expel the greenish liquid called whey. This syneresis process is further driven by a cooking stage. The increase in temperature causes the protein matrix to shrink due to increased hydrophobic interactions, and also increases the rate