Upload
fsnutri
View
234
Download
3
Tags:
Embed Size (px)
Citation preview
FOOD BIOTECHNOLOGY
CHEESE MAKING
Presented by
G.SuganeshwariII- M.Sc., Food Science and Nutrition
CHEESE MAKING
• Cheese 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 CHEESES
The 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:
a. Very hard (maximum 34% moisture)
b. Hard (maximum 39% moisture)
c. Semi-hard/Semi-soft (39-50% moisture)
d. Soft (50-80% moisture)
Types based on mode of ripening:
a. Bacteria ripened: Ripening is brought about by different bacteria like lactoccoci, lactobacilli,leuconostocs, propionibacteria and brevibacteria etc.
b. Mold ripened: Ripening is brought about by mold species like Penicillium.
c. Unripened: Ripening is not done.
COMPOSITION
Cheese constituents, viz., fat, protein, moisture, minerals and vitamins differ
greatly with the variety of the product.
Types of cheese
Moisture (%)
Fat (%) Protein Calcium (%)
Vitamins Energy content
(Kcal/100g)Vit-A(µg/100g)
Thaimin(mg/100g)
Riboflavin(µg/100g)
Hard (Cheddar)
35.0 33.0 26.0 0.83 380 50 0.50 400
Semi-Hard(Edam)
43.0 24.0 26.0 0.76 250 60 0.35 320
Blue-Veined (Roquefort)
40.0 31.0 21.0 0.32 300 30 0.70 360
Soft (camembert
51.0 23.0 19.0 0.38 240 50 0.45 280
Unripened (Cottage)
79.0 0.4 16.9 0.09 3 30 0.28 82
Method of Manufacture
The 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)
Cutting
Healing/contracting
Foreworking
Pre-drawing
Cooking/Scalding
Agitation or stirring out
Draining and washing
Cheddaring
Milling
Salting
Hooping/moulding
Pressing
Curing/ripening
CHEESE
MICROBIOLOGICAL ASPECTS OF CHEESE-MAKING
Biological agents
Following three biological agents are required for cheese making,
Milk
Starter Cultures
Rennet
MILK FOR CHEESE MAKING:
Milk
Pasteurization
Starter Addition (0.5-1.25%)
and Souring
Renneting
Cont..... Curd
Cutting and Healing
Cooking/Scaling
Setting of Curd Without Stirring (Matting)
Cutting into Block “Cheddaring” or Turning and Stacking
Milling
Salting
Whey
Cont.......
Moulding (Hopping)
Pressing
Cheese Curd Blocks
Packaging/Boxing
Ripening
Cheese
Manufacture of Emmental (swiss) Cheese.
Milk (Raw)
Starter Addition and Souring
Renneting
Curd
Cutting
Scalding /Cooking
Setting of Curd
Whey
Cont.... Mould filling
Pressing and Turning
Salting
Drying
Warm /storage (Eye formation 22⁰ – 24 ⁰ C/6-8 weeks)
Ripening
Cheese
Production of Edam and Gouda Cheese.
Milk
Pasteurization
Renneting
Curd
Cutting
Stirring
Washing
Whey (Half)
Cont....Scalding/Cooking
Moulding(Hopping)
Pressing
Salting
Ripening (3-4 weeks at 12⁰ – 14 ⁰ c)
Turning
Washing
(Complete) whey
Cont....
Turning
Waxing, Wrapping
Cheese
BASIC STEPS IN CHEESE MAKING
The process of cheese making involves two basic phenomenon:
Preparation of cheese curd
Ripening 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 CHEESE
Ripening (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.
i) Ripening agents: Cohn was the first to correlate the cheese maturation with
bacterial activity in 1875.
ii) Most of the micro-organisms isolated by him from, cheese were rods which
when inoculated in milk produced cheesy aroma.
iii) Subsequently, a number of theories were proposed on cheese ripening.
iv) It believed that cheese maturation is an enzymatic process wherein enzymes
are liberated on autolysis of micro-organisms.
v) Micro-organisms and enzymes are, therefore, believed to constitute the two
basically required biological agents for cheese ripening.
PHYSICAL CHANGES
Body:
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 CONTROL
Cheese 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.