Cheese making

Introduction

• Cheese is a generic term for a diverse group of milk- based food products. Cheese is produced throughout the world in wide-ranging flavours, textures, and forms.

• Cheese consists of proteins and fat from milk, usually the milk of
cows, buffalo, goats, or sheep. It is produced by coagulation of the milk protein casein.

Objective of cheese making

 To obtain the optimum cheese composition with respect to moisture, acidity (pH), fat, protein and minerals (especially calcium)

 Establish the correct structure of the cheese at the microscopic level; and

 Ripen to perfection. Grouped according to texture and basic manufacturing procedures there are seven families of cheese.

First Step
• Milk from the evening milking is allowed to stand overnight. By natural processes, this milk will have partially separated during its overnight standing period. The cream is skimmed off, and the partially skimmed milk is combined with whole milk from the morning milking.

Second Step
The milk is gradually heated to 30 to 35 C (86 to 95 F) before acidification and coagulation.

Step 3

• Acidification: Starter culture is added to milk to change lactose (milk sugar) into lactic acid. This process changes the acidity level of the milk and begins the process of turning milk from a liquid into a solid.

Starter culture

• Fermentation starters (called simply starters within the corresponding context) are preparations to assist the beginning of the fermentation process in preparation of various foods and fermented drinks. A starter culture is a microbiological culture which actually performs fermentation.

Step 4

Coagulation: Rennet is added to further encourage the milk to solidify , forming a custard -like mass. rennet

• .Rennet An enzyme used to coagulate milk during the cheese making process. Rennet is derived from one of four sources: the stomach lining of a young calf (the enzyme rennin is found in the stomach lining of animals because it aids in the digestion of their mother’s milk)

• plants (typically thistle)

• microbes in fungus and yeast

• Genetically engineered rennet that imitates animal rennet.

Step 4

Cutting:- It’s then cut into small pieces to begin the process of separating the liquid (whey) from the milk solids (curds).Large curds are cooked at lower temperatures , yielding softer cheeses like Mascarpone and Ricotta. Curds cut smaller are cooked at higher temperatures, yielding harder cheeses like Gruyere and Romano

Step 5

Stirring, Heating & Draining:- Cheese makers cook and stir the curds and whey until the desired temperature and firmness of the curd is achieved. The whey is then drained off, leaving a tightly formed curd.

Here you can see the cheese maker taking some of the whey out of the vat.

Step 6

• Salting: Salt adds flavour and also acts as a preservative so the
cheese does not spoil during long months or years of ageing. It also
helps a natural rind to form on the cheese. There are several ways to use salt. Salt can be added directly into the curd as the cheese is
being made. The outside of the wheel of cheese can be rubbed with salt or with a damp cloth that has been soaked in brine. The cheese
can also be bathed directly in vat of brine. Concentrated brine. adding the salt directly into the drained curd

Step 7

 Curd Transformation
Different handling techniques and salting affect how the curd is transformed into the many cheese varieties made.

• Shaping:

Step 8

The cheese is put into a basket or a mold to form it into a specific shape. During this process, the cheese is also pressed with weights or a machine to expel any remaining liquid. Pressing determines the characteristic shape of the cheese and helps complete the curd formation. Most cheeses are pressed in three to 12 hours, depending on their size.

Step 9

Ripening: Referred to as affinage, this process ages cheese until it
reaches optimal ripeness. During this process, the temperature and humidity of the cave or room where the cheese ages is closely monitored. For some cheeses, ambient molds in the air give the cheese a distinct flavour. For others, mold is introduced by spraying it on the cheese (brie) or injecting it into the cheese (blue cheese). Some cheeses must be turned, some must be brushed with oil, and some must be washed with brine or alcohol.

Aging should take place in a controlled environment. Different cheeses required different temperatures and humidity’s, however in a small refrigerator temperature is kept at 55°F and 85% humidity. During aging , the cheese should be rotated or flipped periodically to prevent moisture from settling in the cheese and to prevent an inconsistent internal consistency.

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PEYNİR VE YOĞURT OLUŞUM MEKANİZMASI
Prof. Dr. Erdoğan KÜÇÜKÖNER
Süleyman Demirel Üniversitesi, Mühendislik-Mimarlık Fakültesi, Gıda Mühendisliği Bölümü, Isparta
erdogankucukoner@sdu.edu.tr

Özet

Peynir ve yoğurt farklı hayvanlardan elde edilen sütlerden üretilebilmektedir. Birer protein jeli olan bu ürünlerde süt proteinleri ürünlerin oluşumunda temel önem arz etmektedirler. Peynir, sütün peynir mayası denilen uygun proteolitik enzimlerle ve/veya zararsız organik asitlerle pıhtılaştırıldıktan sonra; peynir altı suyunun ayrılması, pıhtının şekillendirilmesi ve tuzlanmasıyla elde edilen, taze veya olgunlaştırıldıktan sonra tüketilen bir süt ürünüdür. Yoğurt, fermentasyonda spesifik olarak Streptococcus salivarius subsp. thermophilus ve Lactobacillus delbruecki subsp. bulgaricus’un simbiyotik kültürleri kullanılarak elde edilen fermente bir süt ürünüdür. Yoğurt ve peynirin duyusal, kimyasal, beslenme ve sağlık açısından özelliklerini, üretimde süte uygulanacak işlemler ile depolama sırasında dikkat edilmesi gereken hususlar etkilemektedir.

Anahtar kelimeler: Süt, peynir, yoğurt.

Abstract

Cheese and yogurt are able to be produced from milks of different animals. Milk proteins in these products, being protein-gels, are important to the product formation. Cheese produced by removing whey from curds and salting and giving shape through press just after coagulation (curdling) of milk by proteolytic enzymes and/or harmless organic acids is a dairy product consumed as a fresh or a ripened. Yogurt is a fermented dairy product produced by specifically inoculation of symbiotic cultures of Streptococcus salivarius subsp. thermophilus and Lactobacillus delbruecki subsp. Bulgaricus during fermentation. Applied processes on milk in the production and the subjects watched out during the storage affect the properties of yogurt and cheese in terms of sensory, chemical, nutrition and health.

Keywords: Milk, cheese, yogurt.

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Kaynak: http://helalvesaglikli.org/docs/kongre/1/sozlu_bildiriler/4_peynir_ve_yogurt_olusum_mekanizmasi_prof_dr_erdogan_kucukoner.pdf

PEYNİR TOZU VE PEYNİR ALTI SUYU TOZU ÜRETİMİ
Prof. Dr. Erdoğan KÜÇÜKÖNER
Süleyman Demirel Üniversitesi, Mühendislik-Mimarlık Fakültesi, Gıda Mühendisliği Bölümü, Isparta
erdogankucukoner@sdu.edu.tr

Özet
İnsan hayatındaki öneminden dolayı, sütün ürünlere işlenmesi gıda endüstrisinde önemli bir yere sahiptir. Bu süt ürünlerinden biri olan peynir; sütün ısıtılması, starter kültür ilave edilmesi, proteolitik enzimlerle pıhtılaştırılması, pıhtının süzülerek peyniraltı suyundan ayrılması, telemenin tuzlanarak ve baskılanarak şekillendirilmesi ile elde edilen, taze veya olgunlaşmış halde tüketilen besleyici bir süt ürünüdür. Peynir tozları gıda endüstrisinde çok farklı alanlarda kullanılmakla birlikte, en yaygın olarak gıdalara lezzet verme amaçlı kullanılmaktadır. Peynir tozunun bu özelliğinden çerez kaplamaları başta olmak üzere preslenmiş çerezlerde, peynir esaslı soslarda, çorbalarda, patates cipslerinde, tuzlu çeşnilerde ve tuzlu bisküvilerde yaralanılmaktadır. Sütünün peynir yapımından sonra katı kısımdan ayrılan geride kalan sıvı kısmına ise peynir altı suyu denir. Peynir altı suyu tozu gıda sanayinde; şekerlemeler, unlu mamuller, et ürünleri, çorbalar, soslar, içecekler gibi birçok üründe kullanılmaktadır. Ayrıca, hayvan beslenmesinde ucuz ve yüksek kaliteli protein kaynağı olmasıyla beraber karbonhidrat kaynağı olarak da tercih edilmektedir.

Anahtar kelimeler: Maya, peynir, süt, peynir altı suyu.

Abstract
Processing of milk has an important place in food industry due to its importance on human-life. One of the dairy product, cheese, produced by heating of milk, addition of starter culture, coagulation (curdling) by proteolytic enzymes, draining of whey, salting and giving shape by press is a nutritious product consuming as a fresh or a ripened. Cheese powder utilized in so many different areas of food industry is widely used as a flavor enhancer
for foodstuffs. This feature of cheese powder is utilized in firstly coating of snack foods, additionally cheese-based sauces, soups, potato chips, salty dressings and in salty biscuits. Remaining aqueous phase, separated from solid part in the cheese production, is named “whey”. In food industry, whey powder is used in different food products like candies, bakery products, meat products, soups, sauces, drinks etc. Furthermore it is preferred for animal-
feeding due to its high carbohydrate content besides to being a cheap and high quality protein source.

Keywords: Yeast, cheese, milk, whey.

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Cheese is defined as the fresh or matured product obtained by draining the whey after coagulating casein, the major protein in milk. The casein is coagulated by acid from selected m/o and / or by milk-clotting enzymes added to the milk. The resulting curd is cubed, cut, heated, drained and salted. Fresh and uncured cheese, such as cottage and cream, can be eaten immediately.

Ripening or uncuring of the knitted or streched curd includes exposure to a temperature humıdıty controlled environment for a specified length of time. Changes during curing are bought about by specially selected enzymes, bacteria, mold, yeast or combinations of these added curing agents in or on the cheese. During ripening nutrients such as protein fat and carbohydrate (lactose) are changed to simpler compounds thatproduce the chacteristic flavour and affect the final texture of the cheese.

We made the cheese using two different methods. One of both is using lactic acid, other is using rennin. In rennin method, we applied pasteurization method except boiling. Also after added rennin we incubated the milk. However we didn’t apply incubation process to the milk added lactic acid. In lactic acid method we observed coagulum, while adding lactic acid to the

There was not big difference in yield between these two methods. But the yield obtained obtained from milk was lower than the others for our sample. This is because of the quality of milk and changes from milk to milk. In acidity, there are some contradictions. In lactic acid method, lactic acid level in whey was bigger than curd’s. But in rennin method, L.A level of whey was smaller than curd’s. On the other hand, the pH level in lactic acid method was smaller than rennin’s. Also pH of whey was smaller than curd in these both methods. All cheese dishes should be cooked at a low temperature for a short time. Excessive heat and overcooking cause fat seperation, stringing, and the tougheningof the cheese.

It is generally quite straight forward to locate the sources of enzymes; the natural sources of enzymes are where nature needs them. It comes as no surprise that rennet had traditionally been isolated from the fourth stomach of young calves because digestion by suckling calves is nature’s primary way of processing cow milk

Although rennet is naturally excreted from a calf’s stomach lining, extracting it from its natural source is not economical. Other proteases can also convert casein to para-casein, but their action does not stop there. They further degrade the curd to soluble subunits. Fortunately, large quantities of rennet of consistent quality can now be produced easier and cheaper in a well controlled environment by microbial fermentation. A word of caution is in order here. Enzymes as a class of chemicals are not generally considered as dangerous, toxic, nor poisonous; they do not cause skin irritations or burns as acids or bases. Some exceptions are proteases that catalyze the breakdown of protein molecules to amino acids components. Because meat is mainly protein, protease can digest the soft moist sections of the skin. We can all imagine how that is going to feel.

Lactic acid bacteria (LAB) are widely used in the production of fermented dairy products (FDP) due to their specific metabolic activities. The production of lactic acid is essential for the production of FDP and the development of their typical flavor. Acidification, production of organic acids, and other antimicrobial substances, such as bacteriocins, contribute greatly to the preservation of FDP by inhibiting pathogens and other contaminants.

The transformation of lactose by lactic cultures improves the digestibility of FDP. Various metabolic and enzymatic activites of LAB lead to the production of volatile substances,which contribute to flavor, aroma and texture developments in FDP. The harder the cheese, the more milk is required to produce it. For one kilo of cream cheese, 4- 5 litre milk is required. For hard cheese, it is triple the quantity of milk.

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The main lactic acid formers are homofermentative lactic acid bacteria such as Streptecoccus thermophilus, Lactococcus lactis, Lactococcus lactis subspp cremoris. Lactic acid vary in rate of acid production. The rate is influenced by temperature, pH, antibiotics, bacteriophage, stimulants, inhibitory compound, milk composition, available nutrients, condition of the culture, strain compatibility and strain dominance. The term starter culture refers to a culture of lactic acid bacteria in food which is used to induce a lactic acid fermentationto produce fermented products.the particular lactic acid bacteria required in any given starter culture depend on the purpose of use. In cheese making an active production of lactic acid is an essential requrement and cultures may consist of Lactococcus lactis, Lactobacillus helveticus, Lactobacillus bulgaricus, of combination of these with or without aroma forming bacteri. Microbial spoilage in cheese is generally limited because of the combined effect of acid, salt and low moisture. Fresh cheese may be spoiled by gram (-) psychrotrophic bacteria (Flavobacterium, Psedomonas or Alcaligenes), coliforms, yeast and molds that enter as post- pasteurization contaminants. The most common pathogens in cheese are Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella, Brucella.

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Cheese is defined as the fresh or matured product obtained by draining the whey after coagulating casein, the major protein in milk. The casein is coagulated by acid from selected m/o’s and / or by milk-clotting enzymes added to the milk. The resulting curd is cubed, cut, heated,drained and salted.Fresh and uncured cheese, such as cottage and cream, can be eaten immediately. Ripening or uncuring of the knitted or streched curd includes exposure to a temperature humıdıty controlled environment for a specified length of time. Changes during curing are bought about by specially selected enzymes, bacteria, mold, yeast or combinations of these added curing agents in or on the cheese. During ripening nutrients such as protein fat and carbohydrate (lactose) are changed to simpler compounds thatproduce the chacteristic flavour and affect the final texture of the cheese.

We made the cheese using two different methods. One of both is using lactic acid, other is using rennin. In rennin method, we applıed pasteurization method except boilng.Also after added rennin we incubated the milk. However we dıdn’t apply incubation process to the milk added lactic acid. In lactic acid method we observed coagulum, while adding lactic acid to the milk. No process dıd ın thıs method for obtain cheese beside this.

There was not big difference in yield between these two method. But in acidity, there are some contradiction. In lactic acid method, lactic acid level in whey was bigger than curd’s. But in rennin method, L.A level of whey was smaller than curd’s. On the other hand, the pH level in lactic acid method was smaller than rennin’s. Also pH of whey was smaller than curd in these both method.

All cheese dıshes should be cooked at a low temperature for a short time. Excessive heat and overcooking cause fat seperation, stringing, and the tougheningof the cheese. Hard cheese such as cheddar, swiss and parmesan may be kept for several weeks. Soft cheese such as cream, cottage, neufchatel, fresh rıcotta, brie and camembert are hıghly perıshable and should be used within days after purchase.

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Cheese is defined as the fresh or matured product obtained by draining the whey after coagulating casein, the major protein in milk. The casein is coagulated by acid from selected m/o’s and / or by milk-clotting enzymes added to the milk. The resulting curd is cubed, cut, heated,drained and salted.Fresh and uncured cheese, such as cottage and cream, can be eaten immediately.

Ripening or uncuring of the knitted or streched curd includes exposure to a temperature humıdıty controlled environment for a specified length of time. Changes during curing are bought about by specially selected enzymes, bacteria, mold, yeast or combinations of these added curing agents in or on the cheese. During ripening nutrients such as protein fat and carbohydrate (lactose) are changed to simpler compounds that produce the chacteristic flavour and affect the final texture of the cheese.

We made the cheese using two different methods. One of both is using lactic acid, other is using rennin. In rennin method, we applıed pasteurization method except boilng.Also after added rennin we incubated the milk. However we dıdn’t apply incubation process to the milk added lactic acid. In lactic acid method we observed coagulum, while adding lactic acid to the milk. No process dıd ın thıs method for obtain cheese beside this.

There was not big difference in yield between these two method. But in acidity, there are some contradiction. In lactic acid method, lactic acid level in whey was bigger than curd’s. But in rennin method, L.A level of whey was smaller than curd’s. On the other hand, the pH level in lactic acid method was smaller than rennin’s. Also pH of whey was smaller than curd in these both method. All cheese dıshes should be cooked at a low temperature for a short time.

Excessive heat and overcooking cause fat seperation, stringing, and the tougheningof the cheese. Hard cheese such as cheddar, swiss and parmesan may be kept for several weeks. Soft cheese such as cream, cottage, neufchatel, fresh rıcotta, brie and camembert are hıghly perıshable and should be used within days after purchase.

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