Group A

Ayesha IshfaqLubna Tauhidi

Komal Binte AjmalHusam Bin TawseenMuhammad Ahmed

Sehrish JavedZara Taimoor

CHEESEMAKING BASICS

MILK

ACIDIFICATION

COAGULATION

CUTTING

CURDS WHEY

SALTING

SHAPING

RIPENING

STARTER CULTURE

RENNET

COTTAGE CHEESE

•14-30% DM and 0-75% fat

•Acid dominated coagulation

•Spontaneous draining by

optional slicing or moulding

•Salting: mixing with salt

•No ripening, cheeses

consumed after packaging

•44-55% DM and 30-55% fat

•coagulation rennet dominant

•Draining by mechnical

treatments : Slicing, mixing,

pressing

•Salting to 1.5%-2% NaCl by

bringing

•Ripening : 12-60 d (or longer)

CHEDDAR CHEESE

SIGNIFICANCE IN PAKISTAN

• 5th position among the top milk producing countries of the world.

• Major industries: Dairy House Pakistan®, Adam's Milk Foods (Pvt.) Ltd., Azhar & Co and Tetra Pak®.

Necessity of cheese fermentation

• For preservation purposes.• For flavor • For texture• As a carrier for probiotics• Rich in nutrients: high content in protein,

calcium, riboflavin, and vitamins A and D

Preservation of milk

• For people of that time, the most important incentive for cheese production was that cheese constituted a highly nutritious, high energy food with a much longer shelf life than liquid milk.

• Caesin and whey proteins are concentrated• Reduced water content from 80% to 20%-56%

Flavor and texture• Primary fermentation

The texture of the coagulum is dependent on the starter culture used, protein content of the milk, the pH, and the level of calcium ions in the milk.

• Cheese ripening – Individuality and unique characteristics.

– Flavor and texture development is due to glycolytic, proteolytic, and lipolytic activities being the primary events during cheese ripening.

– The extent of protein and fat degradation is determined by the moisture, pH, and salinity in the cheese. excessive proteolysis and lipolysis can lead to rancid flavors and undesired texture.

Cheese as a carrier for Probiotics

• Sufficient number of bacteria should be present at the time of consumption, expressing health benefits

• Should not exert adverse effects on the aroma and flavour of the final product

Fresh cheese as a carrier

• Ideally suited to serve as a carrier for probiotic bacteria– Unripened cheese, storage occurs at refrigeration

temperatures, shelf life is rather limited

• Probiotic addition:– Together with the starter culture – Together with cream and salt

Starter Cultures

Primary Cultures • mesosphelic culture• use when a clean cheese flavor and a very

close curd texture.• Ideal for semi-soft and fresh cheeses such as:

Cheddar and cottage etc.• Contains– Lactococcus lactis subsp. lactis– Lactococcus lactis subsp. cremoris

• Temp growth range is 10° - 42°C (50°- 102° F.)

Secondary culturesSecondary Cultures These are mold, yeast, enzyme, and bacterial powders.

These cultures are either added to the milk between layers of curds, or applied to the surface of the finished cheese.

• Brevibacterium linens, requiring a high pH reading for successful growth.

• Geotrichum candidum is a rapid-developing mold that overpowers unwanted mold on moist cheese.

Secondary cultures cont

• Penicillium candidum produces a white, fuzzy mold on the surface of the cheese.

•  Penicillium roqueforti creates colored veins and streaks in cheeses such as blue, gorgonzola, Roquefort and Stilton.

Biochemical Pathways

Involved in Cheese making, ripening and its effect on cheese quality.

Main Steps in Cheese Making

• Milk, the substrate used for cheese Making contain,– Water, fats, Carbohydrates, Proteins, phosphate & Ca++

• Milk Sugar (Lactose) is converted into Lactic acid by Lactic acid Bacteria.

• Milk protein Caseinogens is converted into Casein by an enzyme renin.

• Casein Molecules form micelles which aggregate curd.

• Tri-glycerides (Fats) and minerals trap in Casein network.

Factors that Alter the End Product PH:

• Melting requires fusion of casein micelles. Lower PH favors casein fusion.

• But PH lower then optimum results in aggregation of Casein.

• Cheese become brittle, have Reduced Melt, Non-stretchy .

Fat content:

• If more Fat globules, Casein aggregates are less dense & further apart.

• This weakens the casein network, results in a cheese that melts and stretches more readily and at a cooler temperature than a lower fat cheese

Factors affecting cheese properties

• The question here is :“ What makes one kind of cheese different from another?”• Milk– Different animals• Cow • Goat • Sheep – Different fractions• Whole, partially skim, skim.

Factors affecting cheese properties

• Temperature of processing– Higher temperature of processing = tougher cheese curd

• Method of curd precipitation– Rennin = more elastic curd– Acid = less elastic curd

• Pressure used in whey removal– No pressure = soft cheese– Pressure = harder cheese

• Microorganisms used

Factors affecting cheese properties

• Length of ripening– Short ripening - mild cheese– Long ripening - sharp cheese

• Amount of salt added–Results in slow ripening

Optimum Conditions for the Process

• Pasteurization: 72-73 Degree Celcius. 15-20 seconds.

• Coagulation: Acidification of casein is required. PH = 4.6-4.7

• Salting: Salt is added, usually 0.5-2%. Curd is exposed to salt at PH of 5.3-5.6 5-6 Hours. Salt content of Cheddar = 1.75-1.95%

• Ripening and Storage:

Different environmental conditions for different varieties of cheese.

For Cheddar Cheese, ripening temperature is is 4-8 Degree Celcius.

Ripening Time may vary from a few months upto 8-10 months.

Preservation of Fermented Product

Bacteriocins action

Unwanted Microbes During Fermentation

• Competitive bacteria: share common ecological niche– For example: closely related species of producer

organism• Spoilage and Pathogenic bacteria: harmful for

final product and human health

How to Avoid Unwanted Microbes

• Using lactobacillus bacteria as starter culture leads to production of “Bacteriocins”

• Adding carbohydrates to alter pH• Addition of salt to inhibit microbial growth

Bacteriocins

• Antimicrobial proteins produced by lactic acid bacteria

1. Against the competitive bacteria. • Lactacin2.Against the spoilage and pathogenic bacteria.• Nicin and Pediocin

Interesting facts about cheese

• Ancient legend: Arab merchant accidently stored his milk in a pouch made out of sheep stomach.

• • Cheddar cheese : named after a village, Cheddar in

Somerset, England, and was popular during the reign Queen Elizabeth.

• There are about 2000 names assigned to cheeses out of which 800 varieties has been well established and 400 varieties described by USDA