Cheese Making in the Lab Scale and a Study of Quality ...

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Vol.04,Issue.41,

October-2015,

Pages:9107-9114

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Cheese Making in the Lab Scale and a Study of Quality Control Procedures

with Lab Made and Purchased Samples of Cheese HAIDAR HASAN MOHAMMD

Dept of Biotechnology, University College of Science, Osmania University, Hyderabad, TS, India.

Abstract: Hundreds of types of cheese from various countries are produced. Their styles, textures and flavors depend on the

origin of the milk (including the animal's diet), whether they have been pasteurized, the butterfat content, the bacteria and mold,

the processing, and aging. Herbs, spices, or wood smoke may be used as flavoring agents. Cheese is valued for its portability,

long life, and high content of fat, protein, calcium, and phosphorus. Cheese is more compact and has a longer shelf life than milk,

although how long a cheese will keep may depend on the type of cheese; labels on packets of cheese often claim that a cheese

should be consumed within three to five days of opening. In production the main rules are: minimizing expense, while attaining

optimum quality. The first requirement can sometimes be in conflict with the latter. To fulfill the two requirements, the cheese

manufacturing process must be adjusted constantly. We have designed programs for the final cheese quality by controlling

manufacturing variables such as: 1. Min. - pH and pH after 6 hours 2. % Moisture 3. Bacterial flora the pasteurized milk of the

brand name Vijaya Milk was used for cheese making. One liter of the milk is heated and cheese is made out of that successfully.

The characteristics and the technology which are described suggest in developing countries traditional milk product like butter

and cheese are made in general under primitive conditions which results in low yield and poor quality of the product. Poor

sanitary practices in local cheese processing results in public or consumers health hazard due to the presence of pathogenic

bacteria, mold and yeast. The result of the present protocol of cheese making is shown in the above figure and the texture of

cheese was found to be smooth. The quality control of the lab made cheese samples and purchased cheese samples was carried

out and the results were as follows:

Keywords: Lactic Acid Bacteria (LAB), Cheese, LDL-C (LDL Cholesterol).

I. INTRODUCTION

Cheese is a fermented food derived from the milk of

various mammals. Since humans began to domesticate milk-

producing animals around 10,000 B.C. , they have known

about the propensity of milk to separate into curds and whey.

As milk sours, it breaks down into curds, lumps of

phosphoprotein, and whey, a watery, grey fluid that contains

lactose, minerals, vitamins, and traces of fat. It is the curds

that are used to make cheese, and practically every culture on

Earth has developed its own methods, the only major

exceptions being China and the ancient Americas. The first

cheeses were "fresh," that is, not fermented. They consisted

solely of salted white curds drained of whey, similar to

today's cottage cheese. The next step was to develop ways of

accelerating the natural separation process. This was

achieved by adding rennet to the milk. Rennet is an enzyme

from the stomachs of young ruminants—a ruminant is an

animal that chews its food very thoroughly and possesses a

complex digestive system with three or four stomach

chambers; in the United States, cows are the best known

creatures of this kind. Rennet remains the most popular way

of "starting" cheese, though other starting agents such as

lactic acid and various plant extracts are also used. By A.D.

100 cheese makers in various countries knew how to press,

ripen, and cure fresh cheeses, thereby creating a product that

could be stored for long periods. Each country or region

developed different types of cheese that reflected local

ingredients and conditions. The number of cheeses thus

HAIDAR HASAN MOHAMMD

International Journal of Scientific Engineering and Technology Research

Volume.04, IssueNo.41, October-2015, Pages: 9107--9114

developed is staggering. France, famous for the quality and

variety of its cheeses, is home to about 400 commercially

available cheeses.

The next significant step to affect the manufacture of

cheese occurred in the 1860s, when Louis Pasteur introduced

the process that bears his name. Pasteurization entails heating

milk to partially sterilize it without altering its basic chemical

structure. Because the process destroys dangerous

microorganisms, pasteurized milk is considered more

healthful, and most cheese is made from pasteurized milk

today. The first and simplest way of extending the length

cheese would keep without spoiling was simply ageing it.

Aged cheese was popular from the start because it kept well

for domestic use. In the 1300s, the Dutch began to seal

cheese intended for export in hard rinds to maintain its

freshness, and, in the early 1800s, the Swiss became the first

to process cheese. Frustrated by the speed with which their

cheese went bad in the days before refrigeration, they

developed a method of grinding old cheese, adding filler

ingredients, and heating the mixture to produce a sterile,

uniform, long-lasting product. Another advantage of

processing cheese was that it permitted the makers to recycle

edible, second-grade cheeses in a palatable form.

Prior to the twentieth century, most people considered

cheese a specialty food, produced in individual households

and eaten rarely. However, with the advent of mass

production, both the supply of and the demand for cheeses

have increased in 1955, 13 percent of milk was made into

cheese. By 1984, this percentage had grown to 31 percent,

and it continues to increase. Interestingly, though processed

cheese is now widely available, it represents only one-third

of the cheese being made today. Despite the fact that most

cheeses are produced in large factories, a majority are still

made using natural methods. In fact, small, "farmhouse"

cheese making has made a comeback in recent years. Many

Americans now own their own small cheese-making

businesses, and their products have become quite popular,

particularly among connoisseurs.

II. REVIEW OF LITERATURE

Cheese is a food derived from milk that is produced in a

wide range of flavors, textures, and forms by coagulation of

the milk protein casein. It comprises proteins and fat from

milk, usually the milk of cows, buffalo, goats, or sheep.

During production, the milk is usually acidified, and adding

the enzyme rennet causes coagulation. The solids are

separated and pressed into final form. [1] Some cheeses have

molds on the rind or throughout. Most cheeses melt at

cooking temperature. Hundreds of types of cheese from

various countries are produced. Their styles, textures and

flavors depend on the origin of the milk (including the

animal's diet), whether they have been pasteurized, the

butterfat content, the bacteria and mold, the processing, and

aging. Herbs, spices, or wood smoke may be used as

flavoring agents. The yellow to red color of many cheeses,

such as Red Leicester, is produced by adding annatto. Other

ingredients may be added to some cheeses, such as black

peppers, garlic, chives or cranberries. For a few cheeses, the

milk is curdled by adding acids such as vinegar or lemon

juice. Most cheeses are acidified to a lesser degree by

bacteria, which turn milk sugars into lactic acid, and then the

addition of rennet completes the curdling. Vegetarian

alternatives to rennet are available; most are produced by

fermentation of the fungus Mucor miehei, but others have

been extracted from various species of the Cynara thistle

family.

Cheese is valued for its portability, long life, and high

content of fat, protein, calcium, and phosphorus. Cheese is

more compact and has a longer shelf life than milk, although

how long a cheese will keep may depend on the type of

cheese; labels on packets of cheese often claim that a cheese

should be consumed within three to five days of opening.

Generally speaking, hard cheeses last longer than soft

cheeses, such as Brie or goat's milk cheese. Cheese makers

near a dairy region may benefit from fresher, lower-priced

milk, and lower shipping costs. The long storage life of some

cheese, especially if it is encased in a protective rind, allows

selling when markets are favorable. A specialist seller of

cheese is sometimes known as a Cheese monger. Becoming

an expert in this field requires some formal education and

years of tasting and hands-on experience, much like

becoming an expert in wine or cuisine. The Cheese monger is

responsible for all aspects of the cheese inventory: selecting

the cheese menu, purchasing, receiving, storage, and

ripening. [2] There is some debate as to the best way to store

cheese, but some experts say that wrapping it in cheese paper

provides optimal results. Cheese paper is coated in a porous

plastic on the inside, and the outside has a layer of wax. This

specific combination of plastic on the inside and wax on the

outside protects the cheese by allowing condensation on the

cheese to be wicked away while preventing moisture from

within the cheese escaping. [3]

A. Etymology

Fig.1. Cheese on market stand in Basel, Switzerland.

The word cheese comes from Latin caseus, [4] from

which the modern word casein is also derived as shown in

Fig.1. The earliest source is from the proto-Indo-European

root *kwat-, which means "to ferment, become sour". More

recently, cheese comes from chese (in Middle English) and

cīese or cēse (in Old English). Similar words are shared by

Cheese Making in the Lab Scale and a Study of Quality Control Procedures with Lab Made and Purchased Samples of Cheese


Volume.04, IssueNo.41, October-2015, Pages: 9107-9114

other West Germanic languages—West Frisiantsiis,

Dutchkaas, GermanKäse, Old High Germanchāsi—all from

the reconstructed West-Germanic form *kāsī, which in turn is

an early borrowing from Latin. When the Romans began to

make hard cheeses for their legionaries' supplies, a new word

started to be used: formaticum, from caseus formatus, or

"molded cheese" (as in "formed", not "moldy"). It is from

this word that the Frenchfromage, Italianformaggio,

Catalanformatge, Bretonfourmaj, and Provençal furmo are

derived. The word cheese itself is occasionally employed in a

sense that means "molded" or "formed". Head cheese uses

the word in this sense.

III. IMPORTANT MICROORGANISMS IN CHEESE

MAKING

The magic that is cheese only really needs four

ingredients to happen: milk, salt, rennet (or some other

coagulant, as I discussed earlier), and microbes. Many

modern cheeses are made with preselected cultures,

consisting of only a few types of microbe, but many

traditional cheeses are inoculated using whey or other

products from previous batches, meaning that they can be

made with dozens of types of microbe, some highly unusual.

This microbial wealth is among the many reasons that

traditional cheeses can be so much more complex than

modern, controlled-inoculation cheeses. Modern

microbiology has yet to fully explain the role of all microbes

in cheese-flavor and cheese-ripening, so the limited selection

of controlled inoculation produces cheeses that may be less

interesting.

A. Lactic Acid Bacteria (LAB)

Lactic acid bacteria are often called "starter cultures", as

they play the main role in converting the basic milk sugar,

lactose, into lactic acid, a step which lowers cheese pH and

makes the cheese inhospitable to many spoilage organisms

and is the first step towards deliciousness. There are

essentially two main families of lactic acid bacteria:

lactococci (sphere-shaped, lactic acid producing bacteria) and

lactobacilli (rod-shaped, lactic-acid producing bacteria).

Streptococci can also play an important role in initial cheese

ripening, and are very important in yogurt-making. Although

many of these bacteria die off after the initial step of cheese

making, there are varieties that survive and continue to

contribute to cheese flavor in many cheeses, especially alpine

(Emmental, Gruyere, etc) and Italian hard (Grana Padana,

Pecorino Romano, etc) cheeses.

B. Prop Ionic Acid Bacteria

These bacteria, and specifically Propionobacter shermanii,

are able to digest acetic acid and convert it to sharp, sweaty-

smelling prop ionic acid and carbon dioxide. The carbon

dioxide is what gives Emmental and other Swiss cheeses

their characteristic "holes", and the prop ionic acid

contributes to their complex, especially sharp bouquet.

Interestingly, several species of propionibacteria inhabit

human skin, and help produce "unwashed" odors.

C. Molds (Blue and White)

Molds love cheese. Leave any cheese in a fridge without

protection and it will quickly be colonized by a fuzzy carpet

of interestingly colored spores. Most of the molds that grow

on cheese are species of Penicillium, but some cheeses, like

St. Nectaire, develop all kinds of crazy surface molds, most

of which are not harmful and in fact contribute to that

cheese's unique flavor. Only two species of blue mold, P.

Roqueforti and P. glaucum, give rise to the unique flavor and

texture of the hundreds of blue cheese which are revered

throughout the world. These blue molds are capable of

growing in remarkably low-oxygen environments, which

makes them perfectly suited for the small cracks in the

interior of a ripening cheese. In fact, cheese makers regularly

pierce and inoculate channels through to-be-blued cheeses in

order to encourage the growth of these molds. Blues, like

Roquefort, Stilton, Gorgonzola, and Cabrales are some of the

most famous cheeses in the world, but blue molds also

frequently grow on the surface of goat cheeses, adding color

and flavor, but without growing in the interior, as is the case

of the unsurpassable Monte Enebro.

White molds, which are found on the outside of all types

of soft-ripened cheeses, are subspecies of P. camembertii

(also called P. candidum). These white molds produce

enzymes that break down the milk proteins of the curds,

leading to the characteristic ripened layer surrounding a firm

interior in many of these cheeses. The flavor compounds that

are produced by this enzymatic breakdown are generally

garlicky or earthy; unfortunately, ammonia is also a by-

product of this breakdown, and so it is advisable to let these

cheeses breathe (sit uncovered) in order to allow the highly

volatile ammonia to dissipate.

D. Smear Bacteria

Fig.2. Munster, clearer of train-cars, home of B. linens.

[Photograph: Matt Ryall on Flickr].

Last but perhaps most notorious are the smear bacteria,

which are responsible for the room-clearing ability of

Epoisses, Münster, and Limburger. These smear bacteria are

officially known as Brevibacter linens as shown in Fig.2.

They can't live in acidic or deoxygenated environments, and

so cannot survive in the interior of cheeses. Since they need

salty (up to 15%), moist environments to grow, they must be

encouraged to do so by continual washing or wiping of the

cheese surfaces, a process which results in the development

of the characteristic red "smear" surface of so-called "washed

rind" cheeses. B. linens excels at breaking down proteins

into, well, stinky odor compounds, producing oniony or




garlicky, fishy, and sweaty aromas. Some cheeses, like the

great alpine cheeses, are wiped only during part of their

ripening, producing a muted complexity of flavor, rather than

the nasal assault that accompanies many cheeses that play

host to B. linens. The aroma of the washed-rind cheeses is

often compared to smelly feet by both fans and detractors, a

fact which is easily understood, as brevibacter are ubiquitous

on human skin, and grow especially well without interference

from personal hygiene as shown in Fig.3.

Fig.3. Cabrales, a cheese ripened with blue Penicillium

molds.

E. Health and Nutrition

The nutritional value of cheese varies widely. Cottage

cheese may consist of 4% fat and 11% protein; some whey

cheeses 15% fat and 11% protein, and some triple-crème

cheeses 36% fat and 7% protein. In general, cheese supplies a

great deal of calcium, protein, phosphorus and fat. A 30-gram

(1.1 oz) serving of Cheddar cheese contains about 7 grams

(0.25 oz) of protein and 200 milligrams of calcium.

Nutritionally, cheese is essentially concentrated milk: it takes

about 200 grams (7.1 oz) of milk to provide that much

protein, and 150 grams (5.3 oz) to equal the calcium.

F. Heart Disease

Fig.4. Average cheese consumption and rates of mortality

due to cardiovascular disease or diabetes.

A review of the medical literature published in 2012

noted that: "Cheese consumption is the leading contributor of

SF (saturated fat) in the U.S. diet, and therefore would be

predicted to increase LDL-C (LDL cholesterol) and

consequently increase the risk of CVD (cardiovascular

disease)." It found that: "Based on results from numerous

prospective observational studies and meta-analyses, most,

but not all, have shown no association and in some cases an

inverse relationship between the intake of milk fat containing

dairy products and the risk of CVD, CHD (coronary heart

disease), and stroke as shown in Fig.4. A limited number of

prospective cohort studies found no significant association

between the intake of total full-fat dairy products and the risk

of CHD or stroke....Most clinical studies showed that full-fat

natural cheese, a highly fermented product, significantly

lowers LDL-C compared with butter intake of equal total fat

and saturated fat content."

G. Dental Health

Some studies claim that cheddar, mozzarella, and Swiss

and American cheeses can help to prevent tooth decay.

Several mechanisms for this protection have been proposed:

The calcium, protein, and phosphorus in cheese may act to

protect tooth enamel. Cheese increases saliva flow, washing

away acids and sugars.

H. Effect on Sleep

A study by the British Cheese Board in 2005 to determine

the effect of cheese upon sleep and dreaming discovered that,

contrary to the idea that cheese commonly causes nightmares,

the effect of cheese upon sleep was positive. The majority of

the two hundred people tested over a fortnight claimed

beneficial results from consuming cheeses before going to

bed, the cheese promoting good sleep. Six cheeses were

tested and the findings were that the dreams produced were

specific to the type of cheese. Although the apparent effects

were in some cases described as colorful and vivid, or

cryptic, none of the cheeses tested were found to induce

nightmares. However, the six cheeses were all British. The

results might be entirely different if a wider range of cheeses

were tested. Cheese contains tryptophan, an amino acid that

has been found to relieve stress and induce sleep.

I. Casein

Like other dairy products, cheese contains casein, a

substance that, when digested by humans, breaks down into

several chemicals, including casomorphine, an opioid

peptide. In the early 1990s, it was hypothesized that autism

can be caused or aggravated by opioid peptides. Studies

supporting these claims have shown significant flaws, so the

data are inadequate to guide autism treatment

recommendations.

J. Lactose

Cheese is often avoided by those who are lactose

intolerant, but ripened cheeses like Cheddar contain only

about 5% of the lactose found in whole milk, and aged

cheeses contain almost none. Nevertheless, people with

severe lactose intolerance should avoid eating dairy cheese.

As a natural product, the same kind of cheese may contain

different amounts of lactose on different occasions, causing

unexpected painful reactions.




K. Hypertensive Effect

Patients taking antidepressant drugs in the class of

monoamine oxidase inhibitors are at risk from suffering a

reaction to foods containing large amounts of tyramine. Some

aged cheeses contain significant concentrations of tyramine,

which can trigger symptoms mimicking an allergic reaction:

headaches, rashes, and blood pressure elevations.

L. Pasteurization

Fig.5. Kesong puti (Philippine Carabao Center, Dairy

plant).

A number of food safety agencies around the world have

warned of the risks of raw-milk cheeses. The U.S. Food and

Drug Administration states that soft raw-milk cheeses can

cause "serious infectious diseases including listeriosis,

brucellosis, salmonellosis and tuberculosis". It is U.S. law

since 1944 that all raw-milk cheeses (including imports since

1951) must be aged at least 60 days. Australia has a wide ban

on raw-milk cheeses as well, though in recent years

exceptions have been made for Swiss Gruyère, Emmental

and Sbrinz, and for French Roquefort as shown in Fig.5.

There is a trend for cheeses to be pasteurized even when not

required by law. Compulsory pasteurization is

controversial. Pasteurization does change the flavor of

cheeses, and unpasteurized cheeses are often considered to

have better flavor, so there are reasons not to pasteurize all

cheeses. Some say that health concerns are overstated, or that

milk pasteurization does not ensure cheese safety. Pregnant

women may face an additional risk from cheese; the U.S.

Centers for Disease Control has warned pregnant women

against eating soft-ripened cheeses and blue-veined cheeses,

due to the listeria risk, which can cause miscarriage or harm

to the fetus during birth.

IV. RESULTS AND DISCUSSION

Using the procedure described in details in materials and

methods cheese is made in the lab. The pasteurized milk of

the brand name Vijaya Milk was used for cheese making.

One liter of the milk is heated and cheese is made out of that

as described in materials and methods as shown in Figs.6 to

11.

Fig.6.Milk boiling on hot plate.

Fig.7. Addition of rennet.

Fig.8. Separation of curds and whey.




Fig.9. Assembling the curd.

Fig.10.Finally prepared cheese.

The result of the present protocol of cheese making is

shown in the above figure and the texture of cheese was

found to be smooth. The quality control of the lab made

cheese samples and purchased cheese samples was carried

out and the results were as follows:

TABLE I:

The characteristics and the technology which are described

suggest in developing countries traditional milk product like

butter and cheese are made in general under primitive

conditions which results in low yield and poor quality of the

product. Poor sanitary practices in local cheese processing

results in public or consumers health hazard due to the

presence of pathogenic bacteria, mold and yeast. Several

microorganisms like spoilage and pathogens such as coli-

forms, lactobacilli, heat resistant Staphylococcus can grow in

cheese or on the surface. Although those human pathogens

may not be present in high count, it may indicate a diseased

udder, unsanitary handling and/or unfavorable storage

temperature. A high count indicates that there is a greater

like-hood of disease transmission. That is the reason why the

quality control of the cheese was performed in terms of

microbial quality of cheese.

Fig.11. Gram stained film of Lactobacillus acidophilus by

oil immersion lens.

A. Colony Morphology

Cheese Samples were spread plated and streaked on MRS

medium to get the pure culture and the morphology of the

colony is observed. Colonies were found to be circular in

shape, white to creamish in color and measured 1-3 mm in

size mostly as shown in Figs.12 and 13.

Fig.12. Colony Morphology – Lactobacillus.




Fig.13. Yeast powder.

B. Colony Morphology

Cheese Samples were spread plated and streaked on YPD

medium to get the pure culture and the morphology of the

colony is observed. Colonies were found to be circular in

shape, white to creamish in color and measured 1-3 mm in

size mostly as shown in Fig.14.

Fig.14. Yeast Growth on YPD Medium.

C. Result

The isolate was found to be negative for indole test.

The isolate was found to be negative for Methyl red test.

The isolate test showed negative test for Vogus

proskauer test.

The isolate showed negative test for citrate utilization

test and results as shown in Figs.15 to 18.

Effect of Temperature on Growth of Organism

Lactobacillus: Lactobacillus is grown at 10,20,27,37 and

55C and the turbidity measured by the OD value at 560 nm is

given in the table below.

TABLE II: Showing the Growth of Organism

Lactobacillus In Terms of OD 560 at Different

Temperatures

Fig.15.Graph showing the Growth of the Lactobacillus at

different temperature.

Effect Of Ph On Growth Of Organism Lactobacillus:

TABLE III: Showing the Growth of Organism

Lactobacillus In Terms of Od 560 At Different Ph

Fig.16. Graph showing the Growth of the organism

Lactobacillus at different pH 4, 5, 6, 7, 8, and 9.




Effect of Carbon on Growth of Lactobacillus:

TABLE IV: Showing the Growth of Organism In Terms

of OD 560 at Different Carbon Sources

Fig.17. Graph showing the Growth of the organism

Lactobacillus at different carbon sources.

Effect Of Nitrogen Source On Growth Of Organism:

Table V: Showing The Growth Of Lactobacillus In Terms

Of OD 560 At Different Nitrogen Sources

Fig.18. Graph showing the Growth of the organism at

different nitrogen sources.

V. CONCLUSION

Cheese is the one of most important dairy product consumed

daily by the diverse group of populations; also its production

can be maximized changing the culture, good source and

manipulating the environmental conditions. The effect of

different variables such as carbon sources, nitrogen sources,

temperature, PH was studied.

VI. REFERENCES

[1] Fankhauser, David B. (2007). "Fankhauser's Cheese

Page". Retrieved September 23, 2007. "''Conversation with a

Cheese Monger''".

[2]"Cheese Paper: How It Saves Your Cheese"

[3]Simpson, D. P. (1979). Cassell's Latin Dictionary (5th

Ed.). London: Cassell Ltd. p. 883. ISBN 0-304-52257-0.

[4]"The History of Cheese: From an Ancient Nomad's

Horseback to Today's Luxury Cheese Cart". The Nibble.

Lifestyle Direct, Inc. Retrieved October 8, 2009.

[5]"Art of cheese-making is 7,500 years old". Nature.

December 12, 2012.

[6]Jenny Ridgwell, Judy Ridgway, Food around the World,

(1986) Oxford University Press, and ISBN 0-19-832728-5.

[7]"History of Cheese". www.gol27.com. Retrieved

December 23, 2014.

[8]"Oldest Cheese Found". Retrieved February 25, 2015.

[9]Notker, §15.

[10]"British Cheese homepage". British Cheese Board. 2007.

Retrieved July 13, 2007.

[11]Quoted in Newsweek, October 1, 1962 according to The

Columbia Dictionary of Quotations (Columbia University

Press, 1993 ISBN 0-231-07194-9, p. 345). Numbers besides

246 are often cited in very similar quotes; whether these are

misquotes or whether de Gaulle repeated the same quote with

different numbers is unclear.

[12]Smith, John H. (1995). Cheese making in Scotland – A

History. The Scottish Dairy Association. ISBN 0-9525323-0-

1.. Full text (Archived link), Chapter with cheese timetable

(Archived link).

Author Profile:

Haidar Hasan Mohammd, Received

Master of Science in 2015 Specialization

in Biotechnology from University

College of Science, Department of

Biotechnology, Osmania University,

Hyderabad.

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