Cheese production

 

Cheese production

• Cheese is a fermented dairy product with different flavour and texture.
• It contains about 120 calories, 8 grams (g) of protein, 6 g saturated fat, and 180 milligrams (mg) of calcium.
• The cheese produced by coagulation of milk protein casein using rennet enzyme.
• Cow, buffalo, goats and sheep milk are used to make cheese.
• Milk has two main parts (water and the solids).
• Whey is the correct name for the liquid.
• Curds is the correct name for the solids.
• During cheese making, the bacterial enzymes or rennet are used to make acidification of milk. It causes casein become coagulate and separate whey and curds. The curd called as “Curdling or Clabbering”.
• The solid curds are then removed by cheese cloth filtration method and drain the whey portion.
• Herbs, spices and wood smoke also used as flavoring agents to make cheese.
• Example

• Lemon, Annatto seed, Cherry, Peppermint, Ginger, Black peppers, Caraway, Garlic, Chives, Cranberries, Aromatic oils (Clove, Spearmint, Rose, Raspberry, Maltol) are used as flavoring agent.

Ingredients

            Milk, coagulant and Flavouring agents

• The main ingredient in cheese is milk.
• The type of coagulant is used to make cheese depends on the type of cheese.
• For acid cheeses, an acid source such as acetic acid (the acid in vinegar) or gluconodelta-lactone (a mild food acid) is used.
• For rennet cheeses, calf rennet or, more commonly, a rennet produced through microbial bioprocessing is used.
• Calcium chloride is sometimes added to the cheese to improve the coagulation properties of the milk.
• Flavorings may be added depending on the cheese.
• Some common ingredients include herbs, spices, hot and sweet peppers, horseradish, clove, spearmint, rose, raspberry, maltol, annatto seed, cherry, peppermint, ginger and port wine are used.

Starter culture

• Starter cultures are used early stage in the cheese making process to enhance the coagulation process by lowering the pH prior to rennet addition.
• The metabolism of the starter cultures contributes desirable flavour compounds.
• Help to prevent the growth of spoilage organisms and pathogens during processing of cheese making.

Example (Bacteria)

Typical starter bacteria include Lactococcus lactis subsp. lactis or cremoris, Streptococcus salivarius subsp. thermophilus, Lactobacillus delbruckii subsp. bulgaricus, Lactobacillus helveticus, Propionibacterium freudenreichii,  Lactobacillus casei, Lactobacillus plantarum.

Sometime yeast and mold are used to enhance the colour and flavour.

Example (Yeast/ Mold)

Torula yeast is used in the smear for the ripening of brick and limburger cheese.

Examples of molds include Penicillium camemberti in camembert and brie, and Penicillium roqueforti in blue cheeses.

Collection of milk

• Milk is collected in a sterile container and check the quality of milk and protein and fat ratio was standardized before cheese making. 
• To optimize the protein to fat ratio to make a good quality cheese with a high yield.

Pasteurization of milk

• The milk may be pasteurized reduce the number of spoilage organisms and improve the environment for the starter cultures to grow.
• low-temperature long time (LTLT) pasteurization. Heat the milk to 63°C for 30 minutes.
• High-temperature short time (HTST) pasteurization. Heat the milk to 71.7° C for 15 seconds.
• After pasteurization the milk is immediately cooled to 5°C or below. 

Incubate with starter culture

The starter LAB bacterial culture is added to the milk and held at 90°F (32°C) for 30 minutes to ripen. The ripening step allows the bacteria to grow and begin fermentation, which lowers the pH and develops the flavour of the cheese.

Add rennet and make curds

• The enzyme rennin is obtained from the stomach of young calves.
• Added to raw, whole milk in liquid or tablet form, it causes the milk protein casein to clabber.
• The rennet is the enzyme was added to make milk protein to form curd.  After the rennet is added, the curd is not disturbed for approximately 30 minutes so a firm coagulum form.

Cut and heat the curd

The curd is allowed to ferment until it reaches pH 6.4. The curd is then cut with cheese knives into small pieces and heated to 100°F (38°C). The heating step helps to separate the whey from the curd. The clabbered milk is cut with a knife into cubes.

Drain whey and texture the curd

• The liquid whey is drained off from the curds, which are then crumbled into pieces. If you make cheese at home, you might use ‘cheesecloth’ to drain the curds.
• This step is called Cheddaring.
• Cheddaring helps to expel more whey, allows the fermentation to continue until a pH of 5.1 to 5.5 is reached, and allows the mats to "knit" together and form a tighter matted structure.
• The curd mats are then milled (cut) into smaller pieces.

Add dry salt

The curd pieces are put back in the vat and salted by sprinkling dry salt on the curd and mixing in the salt or salt solution.

Make a cheese into blocks

The salted curd pieces are placed in cheese hoops and pressed into blocks to form the cheese.

Aging of cheese

Before being sold and eaten, the cheese must age, from 60 days to several years.

During this curing process, the tough, rubbery texture of ‘green’ cheese develops into the tender, waxy body of the fully- ripened cheese.

During aging of cheese, the cheese develops an edible ‘rind’. Cheese aged for a short period of time has a ‘mild’ flavor.

Longer aging periods produce an increasingly strong or ‘sharp’ flavor. Sharp cheeses are drier and more crumbly than mild cheeses.

Packing

Cheese may be cut and packed into blocks or be waxed.

Greeting

Dr. K. Amala,

Assistant Professor,

Department of Microbiology,

Sacred Heart College (Autonomous), Tirupattur.

Tamil Nadu, India.