These two Case Studies come from a National Center on Case Studies. I think that a case study approach is very useful in applying knowledge and this is what makes….
Milk is a perfect food. It is a part and parcel of the diet of all young and old. It is essential for the proper growth of the human body. It is a balanced diet. It contains proteins, carbohydrates, fats, minerals and vitamins in the ratio in which they are needed for the proper development of the body. This is why it best suit; babies and the sick. Milk contains calcium. Newly born babies are fed on mother’s milk. It helps in the formation of bones.
Next to mother’s milk, is cow’s milk. Milk should be boiled before it is taken.
Before boiling, it should be strained through a piece of coarse cloth. Milk loses much of its food value if it is boiled for a longer time. We prepare a lot of things from milk. They are butter, curd, lassi, cheese, cream and a number of sweets which sell like hot cakes. They are relished by every-body.
We use milk in varying quantities in tea. Milk in its purest form is rare now. People have become dishonest. They adulterate milk by adding water to it or they get cream extracted from it. These malpractices destroy the food value of milk.
These days tea is more popular than milk. Tea no doubt is cheaper but it is positively harmful for health. Milk strengthens friends bacteria in our body to resist diseases but tea destroys those bacteria. As far as possible, tea should not be given to children. One main reason why the country people are stronger than city- bred people is that they get milk and milk products in greater measure than the people of cities. Lassi is their favourite beverage. The type of animal, its quality, and its diet can lead to differences in the colour, flavour, and composition of milk.
Infections in the animal which cause illness may be passed directly to the consumer through milk. It is therefore extremely important that quality-control tests are carried out to ensure that the bacterial activity in raw milk is of an acceptable level, and that no harmful bacteria remain in the processed products. Milk fat The price paid for milk is usually dependent upon the milk-fat content, and this may be determined either at the collection stage or at the dairy using a piece of equipment known as a butyrometer. Additionally the specific gravity can be measured using a hydrometer.
This can also be used as an aid to detect adulteration. Bacterial activity Routinely it is necessary to check the microbiological quality of raw milk using either methylene blue or resazurin dyes. These tests indicate the activity of bacteria in the milk sample and the results determine whether the milk is accepted or rejected. Both tests work on the principle of the time taken to change the colour of the dye. The length of time taken is proportional to the number of micro-organisms present (the shorter the time taken, the higher the bacterial activity).
It is preferable to use the resazurin test as this is less time-consuming. For these tests, basic laboratory equipment will be needed such as test-tubes, a water bath, accurate measuring equipment, and a supply of dyes. After collection the milk should ideally be stored at a temperature of 4°C or below. This is necessary to slow the growth of any contaminating bacteria. Phosphatase test For pasteurized milk, it is possible to ensure that pasteurization has been adequately achieved by testing for the presence of the enzyme phosphatase.
The destruction of phosphatase is regarded as a reliable test to show that the milk has been sufficiently heat-processed, because this enzyme (present in raw milk) is destroyed by pasteurization conditions. It is stressed that pasteurization is an effective safeguard against spoilage and food poisoning only if the milk is not re-contaminated after pasteurization. Production of Feed The dairy supply chain begins with growing crops such as corn, alfalfa hay and soybeans to feed dairy cows. About 35 percent of feed is grown on the farm by dairy farmers; the rest if purchased from other farmers.
Milk Production Dairy cows are housed, fed and milked on dairy farms across the country. On average, a cow in the United States gave about 20,576 pounds of milk in 2009. Milk Transport Milk is transported from farm to process company in insulated tanker trucks. The average truck carries 5,800 gallons of milk and travels approximately 500 miles round trip. Processing There are more than 1,000 U. S. processing plants that turn milk into cheese, yogurt, ice cream, powered milk and other products. Packaging Packaging is typically done by the dairy processor.
Both paperboard and plastic containers are designed to keep dairy products fresh, clean and wholesome. Distribution Distribution companies deliver dairy products from the processor to retailers, schools, and other outlets in refrigerated trucks. Retail Milk and dairy products are available at 178,000 retail outlets of all shapes and sizes – from convenience stores and neighborhood groceries, to large discount stores and warehouse outlets. Consumer Milk and milk products deliver nine essential nutrients to children and adults, promoting good health and well-being throughout all stages of life.
The milk contains all the food, including protein, fat, sugar, and other nutrients, a young mammal requires for a long period of time. Milk comes from sheep, cows, and goats. Milk is good for us because we grow up healthy and have a strong body, we have sharp teeth and have energy. Everybody needs milk example: babies, toddlers, sick people, children, elderly and old people. In various parts of the world, goats, reindeer, donkeys, yaks, water buffalo, and sheep are domesticated and milked. In most countries, however, dairy cows provide milk.
Milk and milk products are drunk and eaten in many forms, including buttermilk, cheese, yoghurt, and butter. Milk can be reduced to powder, concentrated in a thick liquid, and used in cooking. Fresh milk sours quickly, but, when changed into forms such as cheeses, it can be kept for a long time. People consume milk in fresh, dried, and condensed forms. The dairy farmers take their cows to the holding area, where they wash their cows for milking. When cows are clean the dairy farmers leads them to a special room called the milking parlor.
The dairy farmers take out the milking machine and attach it on the udder of the cow and begings milking. After few minitues when the cow has given all the milk the dairy farmer weighs the milk and notes the amount in the special diary. Each cow produces about 4500 litres of milk each year. The milk travels from the cows through glass pipes to the milk tank. The milk never touches the air it stays clean and fresh. The milk cools in the tank. After this the dairy farmers clean the milking equipment and feed the cow. The cows eat greens, hay and corn that the dairy farmers grow.
They also eat vitamin feed that helps them make more milk. Later from the cooling tank milk is transported to Process Company in insulated tanker trucks. Before the milk can be sold, it is tested to be sure it is fresh and pure. The milk is also pasteurized, a special process that kills any germs and keeps the milk fresh. The milk is poured into containers to sell in stores. The amount of milk a dairy cow produces varies from month to month. A cow does not produce any milk at all until the first calf is born. The farmer removes the calf 2 days after birth, so that the cow is free to be milked.
She is milked twice a day to keep the milk yield high and is given extra food. The cow is milked for ten months. Within three months after calving (giving birth), she is mated again. During pregnancy the milk yeild falls gradually, and for 2 months before the birth, the cow is dry. For six weeks before the birth, she is given extra food to help her to produce a good milk supply after calving. This is called steaming up. Starting with the month when a calf was born, a calender is made showing how a cow’s milk yield changes over a year.