CHEESE MAKINGPresented byG.Suganeshwari II- M.Sc., Food Science and Nutrition
CHEESE MAKINGCheese is perhaps the most important and popular products of the dairy world.Cheese making has been an age old practice as it served as a very effective means of preserving milk solids through moisture removal by coagulation and had a longer shelf-life besides high nutritive value.Cheese making process as an art several hundred years before christ exactly the same way as the Indian products like dahi.
The method of cheese-making differed from country- to country and region-to-region meet the divers local tastes and requirements which led to the development of numerous varieties of cheeses.
DEFINITION:Cheese is the curd of milk separated from the whey and pressed into solid mass. It is defined as a product made from the curd obtained from milk by coagulating the casein with the help of rennet or similar enzymes in the presence of lactic acid produced by added or adventitious micro-organisms, from which part of the moisture has been removed by cutting, cooking and/or pressing, which has been shaped in and then ripened by holding it for sometimes at temperatures and humidities.
TYPES OF CHEESESThe classification of cheeses is based on a number of factors like raw material, type of consistency, appearance (interior and exterior), fat content, moisture content and ripening methods.However, the most commonly used criteria are the moisture content of the finished product and the mode ripening.
Types based on moisture content:Very hard (maximum 34% moisture)Hard (maximum 39% moisture)Semi-hard/Semi-soft (39-50% moisture)Soft (50-80% moisture)
Types based on mode of ripening:
Bacteria ripened: Ripening is brought about by different bacteria like lactoccoci, lactobacilli, leuconostocs, propionibacteria and brevibacteria etc.Mold ripened: Ripening is brought about by mold species like Penicillium.Unripened: Ripening is not done.
COMPOSITIONCheese constituents, viz., fat, protein, moisture, minerals and vitamins differ greatly with the variety of the product.Types of cheeseMoisture (%)Fat (%)ProteinCalcium (%)VitaminsEnergy content (Kcal/100g)Vit-A(g/100g)Thaimin (mg/100g)Riboflavin(g/100g)Hard (Cheddar)35.033.026.00.83380500.50400Semi-Hard(Edam)43.024.026.00.76250600.35320Blue-Veined (Roquefort)40.031.021.00.32300300.70360Soft (camembert51.023.019.00.38240500.45280Unripened (Cottage)79.00.416.90.093300.2882
Method of ManufactureThe following steps are involved in the manufacture of different varieties of cheese.
Preparation of milk (standardization, maturation, heat treatment etc.)Ripening of milk (with starter culture)Coagulation / Setting (with rennet)CuttingHealing/contractingForeworkingPre-drawingCooking/ScaldingAgitation or stirring outDraining and washingCheddaringMillingSaltingHooping/mouldingPressingCuring/ripening
MICROBIOLOGICAL ASPECTS OF CHEESE-MAKINGBiological agentsFollowing three biological agents are required for cheese making, MilkStarter CulturesRennetMILK FOR CHEESE MAKING:MilkPasteurizationStarter Addition (0.5-1.25%) and SouringRenneting
Cont.....CurdCutting and HealingCooking/ScalingSetting of Curd Without Stirring (Matting)Cutting into Block Cheddaring or Turning and StackingMillingSaltingWhey
Cont.......Moulding (Hopping)PressingCheese Curd BlocksPackaging/BoxingRipeningCheese
Manufacture of Emmental (swiss) Cheese.Milk (Raw)Starter Addition and SouringRennetingCurdCuttingScalding /CookingSetting of CurdWhey
Cont....Mould fillingPressing and TurningSaltingDryingWarm /storage (Eye formation 22 24 C/6-8 weeks)RipeningCheese
Production of Edam and Gouda Cheese.MilkPasteurizationRennetingCurdCuttingStirringWashingWhey (Half)
Cont....Scalding/CookingMoulding(Hopping)PressingSaltingRipening (3-4 weeks at 12 14 c)TurningWashing(Complete) whey
BASIC STEPS IN CHEESE MAKINGThe process of cheese making involves two basic phenomenon:Preparation of cheese curdRipening of cheese which are accomplished through a series of steps, namely, preparation of milk, addition of starter, rennet coagulation of milk, processing of the curd (cutting, healing, fore working, predrawing, cooking, agitation, washing, draining, matting, cheddaring, milling, mixing, hooping, pressing) salting of cheese curd and ripening / curing of cheese curd into final product.
SALTING OF CHEESE CURD The different varieties of cheese are salted at the rate of 1 to 10% of sodium chloride.Salt is added to cheese either as dry salt or as brine by one of the following methods or their combination.Dry salt may be added to cheese milk, dusted on the milled curd in the vat just before hooping (e.g. In cheddar cheese), rubbed on cheese surface or added to creaming mixture.The distribution is affected by different factors, namely, moisture content of the cheese, concentrations of salt/brine applied, time and temperature of exposure and surface area to volume ratio of the cheese.
RIPENING OF CHEESERipening (also referred to as curing, maturing of ageing) of cheese is a process of fresh cheese curd at suitable temperature(s) till it transforms into a finished product of desirable body, texture and flavour.The transforms involves the activity of ripening agents, viz., micro-organisms) on various cheese constituents (mainly lactose, protein and fat) to cause physical, chemical (biochemical) and microbiological changes in the product.
Ripening agents: Cohn was the first to correlate the cheese maturation with bacterial activity in 1875.Most of the micro-organisms isolated by him from, cheese were rods which when inoculated in milk produced cheesy aroma.Subsequently, a number of theories were proposed on cheese ripening.It believed that cheese maturation is an enzymatic process wherein enzymes are liberated on autolysis of micro-organisms.Micro-organisms and enzymes are, therefore, believed to constitute the two basically required biological agents for cheese ripening.
PHYSICAL CHANGESBody:The body of cheese, which refers to its consistency, covers the following characteristics:Firmness, elasticity, plasticity, and cohesiveness.
Texture:In cheese, texture refers to the extend of openness due to presence or absence of holes or spaces in the cheese mass.
Flavour:Production of desirable flavour in cheese is the primary change during ripening process.
MICROBIOLOGICAL SPOILAGES OF CHEESE AND THEIR CONTROLCheese is extremely susceptible to microbiological spoilage.However, there are a number of limiting factors inherent in cheese which can influence the microbiological quality of cheese.These factors include moisture content, residual lactose content, oxygen level, salt concentration and pH of the product.