1. PRINCIPLES OF CHEESE MAKING LEARNED FROM NEPAL DAIRY TRAINING.

2. INTRODUCTION Cheese is the generic term for diverse group of milk – based formed product. It is Coagulated form of milk/curdled milk. To curdle milk means to separate the whey from the curds by coagulation of the milk protein casein by acidification by the enzyme rennet. coagulationcasein Most cheeses are acidified to a lesser degree by bacteria, which turn milk sugars into lactic acid, then the addition of rennet completes the curdling.milk sugarslactic acid The solids are separated and pressed into final form.

3. BENEFITS OF CHEESE Relief from Hypertension & Osteoporosis: - Reduces homocystine, an agent related to heart disease. Maintains bone health Gain weight Dental care Other benefits:  Conjugated Linoleic Acid, Sphingolipids that prevent cancer.  Rich in Vit.B  Enhances blood formation  Facilitates absorption of nutrition in body etc.

4. CASEIN There are two types of protein in milk 1.Whey protein(20%) 2.Casein(80%) 3.Individual casein know as alpha casein, beta casein and kappa casein. Kappa casein are ca insensitive whereas other casein are Ca sensitive. Coagulation occurs in two phase.

5. Coagulation process 1 st Stage: -ve charge part of kappa (k) casein is released. Loss of –ve charge which otherwise prevents from caogulating which is paracasein (insoluble in presence of calcium) 2 nd Stage: Precipitation formed It is because casein particles having lost part of their –ve charge can amalgamate through so called hydrophobic bonds between amino acid side chains of the protein. Calcium is necessary for linkage of +ve charge to –ve charge.

6. INGREDIENTS OR CHEESE MAKING Cheese starter Rennet Mould culture ( in case of mould cheese) Lipase enzyme (Feta cheese) Cheese coating Additives ( Salt, color)

7. TYPES OF CHEESE Coagulation AgentHardness(%MFFS)Acidity pH (min)Common Varieties RennetExtra Hard(<50- 55%) 5.10Parmesan Emmental RennetHard ( <50-55%)5.30Yak Cheese,Cheddar,Cl ose textured with round eyeholes RennetSemi-Hard ( 55- 60%) 5.20Danbo, Gouda, Edam. RennetHard ( 60-65%)5.15 4.7 Ripened in Brine Feta, Blue veined/ mould,Danablue, Roquefort RennetSoft (65-70%)4.5White Surface mould: Camembert AcidVery soft (75-85%)4.5Whole curd grains Cottage cheese.

8. Retention figure It is the percentage of given constituent eg protein, fat etc retained in the cheese. -1st it is 3D Coagulum (casein network) - It contracts -Water and dissolved particles squeezed out -Fat globules & bacteria retained. -Protein Casein is the principal constituent in the coagulum,the retention figure for protein is about 75%. -Fat The fine meshed casein network retains the fat globules.The retention figure for fat is around 92.

9. -Bacteria Appox. 90% of the bacteria of the milk are concentrated in the curd grain. - Lactose Lactose is found as true solution in milk so follows the whey. Retention Figures is low around 3-5% eqvt of amount of whey in cheese. - Ash Ash constituents of milk are found as: 1. true solution (as ions) and 2.colloidal particles linked to the casein particles (Calcium and phosphorus) When rennet cheese is manufactured approx.30-40% of ash goes in the cheese. With acid it is low because ash is released. - Citric Acid Citric acid-approx. 10% of citric acid is linked to the casein together with calcium in the same way as phosphate.

10. Basic principles of cheese making 1.Concentration Milk can be made to coagulate by means of Acidification Less cohesive Both method entails that the casein of milk becomes insoluble and forms unbroken network through out the milk. Cutting can accerate the contraction and therefore causes whey exudation. Renneting Firm and elastic

11. Preservation Cheese curd contains valuable nutrients and it is exposed to destruction by bacteria, yeast and mould. It is therefore necessary to keep the number of harmful microorganism as low as possible and inhibit growth of harmful microorganism that do exit. The no of microorganism can be limited by -good milking hygiene -pasteurization of milk -Good Production hygiene Ripening Cheese curd may be eaten as fresh but it may be subjected to ripening process-a process in which milk solids are changed so as to bring characteristic flavour,consistency and apperance of each variety of cheese.

12. RENNET  It causes the milk to coagulate.  It contains natural complex of enzymes like proteolytic enzymes and active enzyme is the Chymosin or rennin. There are different types of Rennet: 1.Calf rennet: Chymosin 2.Other types: Pepsin or lipase, bovine, porcine. 3.Genetically engineered Rennet: Modified with bacteria, fungi, & yeast to produce chymosin mostly in Aspergillus niger. -Ideal for vegeterian.

14. RENNET  Factors: 1.pH 2.Temperature 3.Calcium concentration 4.Amount of Rennet 5.CaCl 2 6. Nitrate

15. DANISH BLUE CHEESE( DANABLUE) It is light blue veined cheese, creamy cheese which is rindless with distinctly sharp & salty taste. It is representative of semi-hard and semi-soft types of cheese with inside mould formation by Penicillim roqueforti. It was invented in 1927 by Danes in alternative to Roquefort.

16. CAMEMBERT CHEESE Invented by Marie Harel, 1791. It is representive of semi-soft/soft types of cheese with outside surface mould formation by Penicillum camemberti and Penicillium candidum It has characteristic flavour of chemical substances including Ammonia, Succinic Acid & bitter taste is due to ornithine, Caloverine, citriline. It has texture that does not survive on heating.

17. PROCEDURE OF CHEESE MAKING 1.Pasteurization of the Cheese Milk 2.Homogenization 3.Inoculation with the Starter culture 4.Pre-Ripening 5.Cutting of Coagulum 6.Separation of whey and forming curd grain 7.Agitation of whey and cheese grain 8.(Moulding) and turning of the cheese 9.Removing cheese from Moulds 10.Salting 11.Maturing of cheese 12.Packaging and storage.

18. PROCESS OF CHEESE MAKING

19. CHEESE MILK Before the making of the cheese, the milk should be properly evaluated. The milk that we received at Nd’s had 4% Fat, Acidity of 0.15, specific gravity 0.235, pH 6.7 and SNF 7.37. 1.Quality & evaluation of the Cheese milk: Bacterial Content Acid development Renneting ability Aroma, taste & appearance 2. Pasteurization &Treatment

20. 1.Pasteurization: - Must be sufficient to kill bacteria like coliforms which cause early blowing and disagreeable taste. - Done at 63 o C for 30 mins. - We pasteurized the cheese milk by heating and made cheese in home cheese kit.

21. 2. Homogenization: Done at 200 Bar 3. Inoculation with the Starter Culture: 1.6 gm per 8 lts of milk of Mesophilic cultures like Streptococcus lactis, St. cremonis, St. diacetolactis were used and inoculated at 30 o C. Starter Culture 2 Types: Mesophilic Thermophilic -These produce lactic acid and also aroma components and Co 2. Characteristics of Starter Culture  Ability to produce lactic acid in the curd  Ability to break down the protein  Ability to produce Co 2

22. LACTIC ACID BACTERIA USED IN CHEESE MAKING FUNCTIONS: 1.Acid Formation Lactic acid bacteriaLactic Acid 1.Formation of Co 2 & Aroma Lactose+Citric AcidLactic Acid+ Acetic diacetyl+Co 2 1.Formation of protein splitting enzymes 2.Inoculation amount & pre-ripening time 3.Acid development in Cheese a.Lactose / protein ratio Pre-ripening & Acidification 4.PRE-RIPENING: -Done for the culture to mix well at 30 o C for 1 hour. 5. Renneting and addition of mould: -Done at 30 o C for 90 mins.

23. 5.Renneting and Moulding

24. 6.Cutting of Coagulum( 20mm) 9.Whey Drainage 7.Separation of whey 8. Agitation

25. 11.Moulding and Turning of the cheese 12.Removing cheese from Mould 10.Wheying off of cheese grains 13.SALTIN G 14.Maturi ng & Storage.

26. (IV) SALTING: 1.Dry Salting 2.Brine Salting (V) CHEESE RIPENING: Fermentation of lactose and Citric Acid (VI) PROTEIN BREAKDOWN (PROTEOLYSIS): 1.Factors: a. Types & amount of enzymes b. Moisture concentration of cheese c. pH & NaCl d. Storage Temperature