Download as PDF, PPTX
More Related Content
Similar to Cheese fermentation
Cheese fermentation
- 1. Cheese fermentation M.Sc. microbiology 3rdsemester By: Abdul satar sirat 1
- 2. Outline Fermentation Cheese General cheese process type of cheese 2
- 3. Fermentation • is ametabolic process that consumes sugar in the absence of oxygen and produce organic acids, gases and alcohol. • Fermentation in food processing : is the process of converting carbohydrates to alcohol or organic acids using microorganisms like yeasts or bacteria under anaerobic conditions. 3
- 4. Cheese • Cheese isa generic term for a diverse group of milk based food products. • Cheese consists of proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. • It is produced by coagulation of the milk protein casein. 4
- 5. General cheese process •Standardize Milk/Collection • Pasteurization • Culturing • Coagulation • Draining • Cutting • Stirring, Heating & Draining • Addition of Salt or Brine • shaping • Store and Aging(maturation) • Packaging 5
- 6. Collection and Standardizedof milk • Raw milk (as such ) • sick cow milk (antibiotic treatment) • Pasteurized 6
- 7. Pasteurization High temp shorttime 72 C for 15-30 sec • Low temp long time 63 C for 30 min • Hydrogen peroxide treatment After pasteurization ,cooled at 32 C/90 F • Favorable temperature for bacterial growth 7
- 8. Culturing • Add starterculture. • Ripen it at 32 C for 30 min. • Thus fermentation starts. • Starter culture is small amount of bacteria ,added in milk to start ripening by lowering the pH. 8
- 9. coagulation • Rennet isadded to further encourage the milk to solidify , forming a custard like mass • In 29 C/ 85 F • Rennet contain enzyme chymosin which convert k casein into para-k casein and smaller protein macropeptide. • Cheek the coagulation after 30 minutes 9
- 10. draining • When cheesecurd is ready, remove cheese whey. • Presence of water and bacteria cause decomposition of food. • So perform partial dehydration. 10
- 11. Cutting • The curdis cut into small cubes to 'scald' the curd particles. • By hand or automatic curd- cutting mechanism • Cheese whey is expressed from the particles. • And settling down of the curd 11
- 12. Stirring, Heating &Draining Cheese makers cook and stir the curds and whey until the desired temperature and firmness of the curd is achieved. The whey is then drained off, leaving a tightly formed curd. 12
- 13. Addition of salt •Salt adds flavor and also acts as a preservative so the cheese does not spoil during long months or years of ageing. • It also helps a natural rind to form on the cheese. • There are several ways to use salt. Salt can be added directly into the curd as the cheese is being made. The outside of the wheel of cheese can be rubbed with salt or with a damp cloth that has been soaked in brine. The cheese can also be bathed directly in vat of brine. 13
- 14. Shaping • The cheeseis put into a basket or a mold to form it into a specific shape. • During this process, the cheese is also pressed with weights or a machine to expel any remaining liquid. • Pressing determines the characteristic shape of the cheese and helps complete the curd formation. • Most cheeses are pressed in three to 12 hours, depending on their size. 14
- 15. Storage and again(maturation) •The pressed blocks of cheese are either bound with muslin-like cloth, or waxed or vacuum packed in plastic bags to be stored for maturation • Depending on the variety, cheese can be aged from several months to several years. 15
- 16. packaging • Store itin vacuum packed or • airtight plastic bag. 16
- 17.
- 18. Type of cheese Severaltypes on the basis of: 1. Length of aging (cheese maturation) 2. Texture 3. Making method 4. Fat content 5. Milk source 18
- 19. 1. Soft Cheese: •Soft, smooth, creamy texture • No heating and pressing • 50-80% moisture content • As a spread on bread and crackers • Usually not for cooking Example: • Cottage, Ricotta, Mozzarella, Cream, Camembert, Brie, Caciotta 19
- 20. 2. Semi-soft Cheese •More firm and compact • 39-50% moisture content • Can be used for cooking purposes Example: Roquefort, Stilton, Gorgonzola, Danish blue 20
- 21. 3. Semi-Hard Cheese: •Considered as “all purpose” cheese • Pressed to remove most whey during production • 34-45% moisture content • Can be used for sandwiches and snacks Example: Cheddar, Colby, Edam 21
- 22. 4. Hard Cheese: •< 39% moisture content • Long maturation period • Very long shelf life • Can last for 2 years in refrigerator Examples Cheddar, Caciocavallo, Emmental, Gruyere, Swiss 22
- 23. 5. Very HardCheese: • 13-34% moisture content • Very long aging period • Can be up to 2 years Examples Asiago old, Parmesan, Romano, Grana 23
- 24. 6. Processed Cheese: •Made by melting a blend of grated cheese, milk, more salt, food coloring, flavors and seasonings • Can be used for cooking • Long shelf life Examples Processed cheese slices, Cheese spreads 24
- 25.