Presentation on theme: "Worldwide, milk is collected from animals such as: –Cows –Goats –Sheep –Yaks –Water buffalo However the US Dairy industry focuses on the milk produced."— Presentation transcript:
Worldwide, milk is collected from animals such as: –Cows –Goats –Sheep –Yaks –Water buffalo However the US Dairy industry focuses on the milk produced by millions of cows.
Water (87.7%) Human beings, as well as animals require more water than any other nutrient. Lactose (4.7%) Lactose is the main carbohydrate in milk, also called sugar though it is not sweet enough to taste. It can cause digestive problems for people who are lactose intolerant.
Butterfat (3.7%) Butterfat is the fat portion of the milk. The more butterfat in the milk, the richer it tastes. Protein (3.2%) Milk proteins are crucial for making cultured dairy products and cheese. Minerals (0.7%) Milk is an excellent source of minerals needed for growth such as calcium and phosphorus.
Aside from making milk taste rich, butterfat is the most coveted part of the milk. Dairy products are largely defined by the amount of butterfat they contain. Type of Milk Butterfat Content Whole Milk Minimum of 3.5 percent 2% milk (reduced fat) 2 to 2.5 percent 1% milk (low fat) 1 to 1.5 percent Skim milk (nonfat) Less than 0.5 percent
Once the fat levels in the milk are adjusted, the milk is pasteurized. The process of pasteurization heats the milk to specific length of time to kill pathogens. For instance, milk can be pasteurized by heating it to 161°F for 15 seconds or 275°F for 2 to 4 seconds.
Another type of pasteurization is called ultra high temperature. Ultra high temperature (UHT) heats milk to 280°F for 2 to 6 seconds, and then it is sealed in sterilized containers. As a results, UHT dairy products do not need refrigeration until they are opened.
Homogenizations permanently and evenly distributes the butterfat in the milk. Milk that has not been homogenized has a greenish tint and easily separates into a cream layer that floats to the top of a thin watery portion. During the homogenization process, the butterfat is broken into very small droplets. These droplets are so small that they are no longer able to join together and rise to the surface of the milk. Another result of homogenization is that the color of milk becomes bright white.
The composition of milk can also be changed by concentration. Concentration refers to the process of removing water from milk. As water is removed from the milk, the levels of proteins, sugars, and butterfat increases. The three most common concentrated milk products are:
This milk has had 60 percent of the water removed, which yields a thick, rich product. It is sold canned.
This milk has had 60 percent of the water removed and a large amount of sugar added. Sweetened condensed milk is thick, rich, and very sweet. It is sold canned and is commonly used in baked products.
This product is a skim milk that has had nearly all of the water. The resulting white powder does not require refrigeration and has a long shelf life.
Butter represents the dairy product with the highest percentage of butterfat. Churning cream makes butter. (Churning is another word for rapid mixing) As the cream is churned, lumps of butterfat emerge and begin to stick together to form larger and larger pieces of butter.
Eventually, a large mass of butter is produced along with a small amount of watery liquid. This watery liquid is referred to as buttermilk. Salt is added to butter to improve its shelf life. Unsalted butter does not have any added salt and has a short life.
Individually wrapped, one-pound pieces of butter typically called butter prints; packed 36 pounds to a case. This pack is popular with foodservice. Individually wrapped, quarter- pound sticks; packed four sticks to a box and 36 boxes to a case. This pack is commonly sold in grocery stores.
Individually portions, such as cardboard backed patties, foil wrapped chips and cups. Whipped butter is butter that has been mixed with a gas such as nitrogen. The added gas makes the butter soft and fluffy.
Cultured dairy products have been made for thousands of years and remain popular today. They are easily recognized for their sour taste and moderately thick texture. What separates fresh dairy products from cultured dairy products is the addition of “friendly” bacteria.
To make cultured dairy products, fresh milk is first pasteurized to kill any harmful bacteria. Next, specific strains of bacteria are added to the warm milk. Milk is nutrient rich, high in moisture, and has a neutral pH, which makes it a perfect environment for bacterial growth. As the bacteria reproduce, they consume the lactose and produce lactic acid. Therefore, during the incubation period, the dairy product becomes less sweet and noticeably more acidic. The increase in acid also thickens the dairy product.
Once the cultured dairy product reaches the desired stage of thickness and acidity, it is refrigerated. The colder temperature stop bacterial growth, but does not kill the bacteria. In fact, the labels of many cultured dairy products indicate that the cultures are live.
Buttermilk –The name buttermilk originally referred to the watery liquid that remained after churning butter. –But now it is skim milk with strains of bacteria added to make the milk more acidic and to thicken the liquid. –Buttermilk is used in baked products and salad dressings.
Yogurt –Yogurt is a centuries old product. –It is made by adding several strains of bacteria to warm milk. Once the bacteria have changed the flavor, texture and acidity level of the milk, it is often sweetened and flavored before sold. –Adding thickeners such as gelatin or pectin to the yogurt produces some thick varieties of yogurt.
Sour Cream –Is a common product in baked goods and is served as a condiment for savory dishes. –Unlike buttermilk and yogurt, sour cream starts with a high-fat dairy product– light cream. –Finished sour cream must have a minimum butterfat content of 18 percent.
Worldwide, there are literally thousands of varieties of cheese. Cheese varies dramatically in shape, color, and flavor.
What separates cheese from cultured dairy products is the amount of moisture in the finished product. Cultured dairy products have the same amount of moisture as milk, while cheese has less moisture than milk. Reducing moisture levels means that the cheese is less likely to spoil. The more moisture removed from the cheese, the longer it will last. A very dry cheese can last for years without spoiling.
Every cheese begins as milk. In the U.S., most cheese is made from cow’s milk; although cheese made from goat’s and sheep’s milk is becoming more popular. Before cheesemaking begins the fat level is adjusted (higher fat cheeses- fat is added, lower fat cheeses fat is removed from the milk)
Bacteria is then added to the milk. Bacteria increase the acidity, change the flavor, and thicken the milk. A small amount of coagulant (an ingredient that causes the milk to thicken dramatically) is added to the milk. The coagulant that is traditionally added to the cheese is called rennet.
The addition of bacteria and rennet turns the milk into a semisolid mass. The thickened milk is then cut into cubes. These cubes which contain casein proteins (one of the two types of protein in milk) are called curds. As the curds are drained, mixed and sometimes heated, they shrink and whey is expelled. Whey is the watery portion of the milk that contain the whey proteins (the other type of protein in milk).
The more whey that is removed from the curds, the firmer the cheese will be. Salt is also added to the curds to remove even more moisture. The curds are then placed in a mold and perhaps pressed. As this mass of curds ages, it will knit together to form cheese.
Fresh Cheeses Soft Cheeses Medium Firm Cheeses Hard Cheeses Blue Cheese Stretched Cheeses Processed Cheese
Are high in moisture and barely aged Slightly sweet and milky flavored. Since they are high moisture, they spoil more easily than other cheeses (have a short shelf life) Examples: cream cheese, cottage cheese, ricotta
Have elastic or creamy textures When they are well aged, they can even become runny Examples: Brie, Camembert and lightly aged goat cheeses
Have a drier and firmer texture Have a longer shelf life Made with curds that are cut smaller, sometimes the curds are lightly cooked The curds are placed in a mold and pressed which removed the whey. Medium firm cheeses are aged for at least a month before being sold. Examples: Morbier, Monterey Jack, Fontina, Colby
The driest cheese and there for have very long shelf lives Curd is cut into small pieces, cooked at high temps, and firmly pressed into molds. Ages for months or even years. Sometimes referred to as grating cheeses Examples: Parmesan, Cheddar, Swiss, Manchego, Gruyere
The blue color in blue cheese is actually a type of edible mold. The mold that grows inside the cheese intensifies the flavor of the cheese. Not all blue cheeses are blue, the mold can have varying shades of green, grey and blue. Examples: Stilton, Gorgonzola, Maytag Blue and Danish Blue
Not many types, but the most popular category of cheese To make stretched cheeses, hot curds are repeatedly stretched to produce strands of cheese. Stretch cheeses are generally eaten with little aging and have an elastic, medium firm texture. Examples: mozzarella, string cheese and provolone
Vast quantities of processed cheese are eaten daily in America. Most famous member of this category? American cheese! Processed cheese begins with medium firm or hard cheeses that are grated and melted. As the cheese melts, it is mixed with an emulsifier, water and possibly additional fat. The resulting hot cheese paste is then rolled into singles, formed into blocks or squirted into jars.