CHEESE

1. CHEESE

2. Definition of Cheese fresh or mature solid or semi-solid product obtained: • by coagulating milk, skimmed milk, partly skimmed milk, cream, whey cream, or buttermilk, or any combination of these materials, through the action of rennet or other suitable coagulating agents, and by partially draining the whey.

5. TURKEY’S PRODUCTION Beyaz , Edirne ,Teneke ,Salamura % 60 Kaşar % 17 Tulum ve Mihaliç % 12 Others % 11

7. Clarification (1) Cloth filters: to remove debris at the farm. (2) Centrifugal clarifiers, medium speed centrifuges, remove particles which escape filtration. (3) Bactofugation: high speed centrifugal process which separates bacterial cells and spores. Bactofugation removes 95% of the spores of milk ( 4) Microfiltration: 99% reduction of spore forming bacteria

9. Standardization of cheese milk composition milk fat or protein or both. The objective: to obtain the maximum economic return from the milk components. Cheese yield is mainly determined by the recoveries of protein and fat

10. Heat treatments -fully pasteurized milk cheese (63C, 30 min. or 72C, 16 s -raw milk cheese. No heat treatment, more flavor. "held at 20C or more for a period of 60 days

11. Homogenisation : fat globule sizes: from 1–15 to less than 2 micrometer. promoteslipolysis, whitening, and flavour development increases fat recovery and creates smoother texture in cream cheese. Increased cheese yield due to greater moisture retention and improved fat and protein recovery.

12. Other additions before making the curd Calcium chloride (CaCl2)If the milk is of poor quality Saltpetre (NaNO3or KNO3) for Clostridia and/or coliform

13. Annatto :orange color for Cheddar carotenoid similar to -carotene and Vitamin A in structure, but it has no Vitamin A activity. Adding CO2 by artificial means lowers the pH by 0.1 to 0.3 units, improves the quality) result in shorter coagulation time or lesser rennet usage.

14. Development of Starter Cultures LAB occur naturally in raw milk. first commercial cultures: by Chr. Hansen Labs (Denmark) end of the nineteenth century. Microbiology of Starter Cultures Mesophilic Starters (32 C) Lactococcus lactis:the dominant acidifying mesophile Leuconostoc mesenteroides ssp. Cremoris: catabolize citrate to carbon dioxide and the flavor compound, diacetyl.

15. if procedure includes high temperatures, ( Swiss, Parmesan, and Mozzarella), then a thermophilic lactic acid bacterial culture used. Thermophilic Starters(45 C) S thermophilus and species of Lactobacillus (Lb): bulgaricus, helveticus and lactis. Mozzarella, Emmenthal.

16. Function of Starter Cultures 1- acidification, (enhances the expulsion of whey, promotes the development of the texture) 2- texture enhancement, pH dictate the texture 3-flavor development. 4- Eye formation 5- health benefits.

17. possible causes of starter culture inhibition: -antibiotics -natural immunoglobulins bind to bacteria, forming clumps that eventually settle in the vat - inhibitor is formed via the lactoperoxidase reaction -Chemical agents used to sanitize cheese vats can occasionally inhibit cultures -bacteriophages, viruses that infect bacteria

18. coagulation of milk proteins (casein) by one of: A) milk-clotting enzyme, rennet( most cheeses.) B) Direct acidification of milk to pH 4.6, or in situ production of acid by starter bacteria( cottage cheese) C) Heat/acid coagulation, in which hot milk (80–90°C) is acidified to pH 4.6–5.3.(ricotta, quark)

19. Rennets ‘rennet’ : milk-clotting enzyme prepared from calf stomach, ( contains the active enzyme chymosin (rennin). Chickenpepsin and papain are used in some countries for cheese-making. Also, rennets from kid and lamb stomachs are available.

20. Two stabilizing factors: 1-'hairy' layer of surface active protein, called kappa-casein , on the surface of the micelle. 2-negative charge on the micelles. At the pH of milk the micelles are negatively charged so they repel each other.

21. So,two ways to coagulate milk; 1- to remove the hairy layer(enzymic coagulation.) 2- to neutralize the negative charge( by acidification or a combination of high temperature and acidification. )

22. Depiction of the various stages involved in curd formation following proteolysis of κ-casein by chymosin

23. Rennin K-casein para-K-casein+soluble whey pH=6.4-6.0, Ca++ Dicalcium para K-caseinate L. acid (starter culture) Mono calcium para K-caseinate (elastic) More acid Free para K-caseinate (brittle)

24. CHEESE MAKING STEPS Setting the Vat Handling Rennets firm coagulum in 30 - 40 min. must be diluted (about 20 times): uniform distribution.

25. 3 Cutting The Curd Proper cutting: important for quality and yield. Improper cutting: the loss of fines.

26. Determination of curd cutting time to determine cutting time. Manual testing: ready to cut if it breaks cleanly when a flat blade is inserted at 45o angle to the surface and then raised slowly. oscillating viscometry, thermal conductance and sonication have been tested experimentally. Some plants cut by the clock.

28. Curd size ( affects moisture and fat retention) High temperature and low moisture varieties:smallest curd( size of rice grains.) Medium moisture cheeses(Cheddar):1 cm cubes. High moisture varieties like soft ripened cheese:2 cm

29. Manual cutting cutting harps ( stainless steel frame). The knives should be pulled (not pushed) to cut the curd cleanly.

30. Automated cutting curd size:f( design of the vat, agitators,speed of cutting (rpm), duration of cutting) increased cutting timeincreases curd particle size: maximum fat recovery.

31. Example of a conventional cheese vat at different stages: A : during stirring B : during cutting C : during whey drainage D : during pressing Source : Dairy Processing Handbook, Tetrapak Sweden

32. Heating/cooking/scalding promotes contraction of the curd accompanied by expulsion of whey (syneresis).

33. 9.5 Draining Draining time should be uniform at about 20 min to prevent variation from 6 Washing Lactose content can be adjusted by moisture removal (syneresis), fermentation, or leaching with water. Sometimes relatively hot water (eg., Gouda) is used to dry the curd and develop its texture.

34. Pressing The warmer the curd, the less pressure required. demoulding

35. 9.9 Salting ( normally 3-7 %) 1-before pressing,2- surface salting after pressing, 3- brine salting. Purposes of Salting Promote further syneresis Slow acid development suppress spoilage bacteria. Lactics are more salt tolerant than pathogens and spoilage bacteria. Promote controlled ripening and flavour development. Salty flavour

36. Brine salting: Concentration 16 - 25% NaCl Time: 20 kg cheese, 5 days or sometimes several weeks

37. Still, the most commonly used system is to place the cheese in a container with brine. The containers should be placed in a cool room at about 12 – 14°C.

38. Ripening processes: chemical and physical changes breakdown of proteins, lipids and carbohydrates (acids and sugars) modifies flavour, texture. Ripening: from nil for fresh cheese to 5 years interior ripening (most hard ripened cheese such as Cheddar and Italian types) may be ripened with rind formation or may be film wrapped before curing. surface ripening include smear ripened and mould ripened

40. Factors Affecting Yield Casein: principal yield determining factor. ( absorbs water, minerals and own weight) Fat: also a principal yield component. Fat interferes with syneresis and, therefore, also contributes more than its own weight. Cheese moisture. 1% increasecauses about 1.8% increase in cheese yield. Cheese salt. extra 0.1% salt means extra 0.14% yield

41. Defects Caused by Coliform Bacteria coliforms: indication of poor sanitation( killed by pasteurization.) grow rapidly in cheese during the first few days of storage. The metabolites of coliforms : lactic acid, acetic acid, formic acid, succinic acid, ethanol, 2,3-butyleneglycol, H2 and CO2. The production of H2 and CO2results in early gas blowing of the cheese.

43. Manufacture of Blue Cheese( internally mold ripened, P. roquefortii) allow O2 to enter the interior of the cheese and to allow CO2 out. ( cheese to breathe) O2 supply is not generally a problem for surface mould-ripened cheeses, but for internally mould-ripened cheeses, ( a set of large bore needles (D= 0.24 cm) may be used to pierce the cheese for air to penetrate)

44. Cheddar Cheese originated around the village of Cheddar, England, 30% of total cheese production of the World. Moisture:of 35–40%, manufactured by renneting at  30 °C, cutting the coagulum into small pieces, cooking to  40 °C, drainage of the whey and pressing the curd. textured in the vat (‘cheddared’), milled and dry-salted molded, pressed for 12–16 h, and matured for 3–12 months, or longer.

46. Cheese with Eyes Swiss cheese, easy to make but the hardest cheese to make well. depends on two independent processes.: -requires excellent curd handling (correct for eyes to form.) -precise control of fermentation to poduce gas that ultimately results in eye formation. the milk is usually standardized to 3% fat. too much fat: too soft curd not enough fat : too hard ……………….to poor eye development

47. -CO2 formation must be slow and steady. -If too much CO2 is produced all at once or the curd is too firm: large or exploded holes are formed. If the curd is too soft and the weak spots too numerous, then many small eyes will form. -without a rind, the CO2 could escape ( impermeable bags provide an easy remedy)

48. Pizza cheese -stretches a particular distance when a slice is moved from plate to mouth. -remains white and resists browning even when the pizza is baked quickly at extremely high temperatures. -Minimumfat leakage Mozzarella is prized less for its flavor and more for its physical and functional attributes. ( unusual ability to stretch, retain fat, melt evenly, and provide a chewy mouth feel.)

49. moderate browning may be desirable, excessive browning or blistering is undesirable. to reduce the galactose concentration in the cheese - by simply washing the curds, - by using cultures that can ferment galactose.( using mesophilic Lactococcus Lactis, requires lower cooking temp).

50. streching cheese : less proteoylitic activity is required non-stretching cheese: greater proteolysis may be encouraged extensive proteolysis: “soft” and “gummy,” cheese, less amenable to shredding.