History of Pasteurization

History of Pasteurization
Pasteurization is named for the French scientist Louis Pasture (1822-1895). In 1856, 34 year old Louis Pasteur began his fourth year as the Head of Sciences at the University of Lille in France.

In the fall of the same year, Maurice D’Argineau, a local businessman, found Pasteur in his cramped corner lab.

D’Argineau’s consistent failure to make wine from his fields of sugar beets without it going sour was driving him to financial ruin. Pasteur was particular intrigued by the problem since it hinted at the involvement of one of his pet interests and he readily agreed to study the matter.

Although he first experimented with this process in 1862, pasteurization was not put to use until the early twenty century.

In the United States pasteurization was championed by Alice Catherine Evans (1881-1975), a microbiologists who worked for the US department of Agriculture.

Evans suffered from a disease known as brucellosis (undulant fever) and in 1918 she discovered that brucella, the bacterium that caused her disease, could be found in cow’s milk.

Scientists eventually determined that brucella was not the only milk borne bacterium. Milk can harbor other bacteria – such as E. coli, salmonella, and listeria – which can cause harmful and even life threatening infectious in the young, the old, pregnant women and the infirm.

Indeed, unpasteurized cow’s milk was a very common cause of tuberculosis, typhoid fever and salmonellosis.

Evans advocated on behalf of pasteurization for years after her discovery. Finally in the 1930s, milk pasteurization became mandatory under US law.
History of Pasteurization

High Temperature Short Time Process

High Temperature Short Time Process
There are systems for processing canned foods at high temperature for short times. These are referred to as HTST or High Temperature Short Time processes. In such system, commercial sterilization is achieved at temperatures of 280 – 300 F. Large discrete particles cannot be processed by High Temperature Short Time methods because they require some time for heat to penetrate their centers. HTST methods are applied only to liquids, and to foods that have been pureed (mashed bananas, concentrated pea soup, etc).

There are five main ways to preserve foods and remove microorganisms:
Chemicals
Drying
Refrigeration
Canning
Radiation

The History of HTST
The process of pasteurization was named after Louis Pasteur who discovered that spoilage organisms could be inactivated in wine by applying heart at temperatures below its boiling point. The process was later applied to milk and remains the most important operation in the processing of milk.

There are various methods of pasteurization. In early 1900’s a batch method as used where a tank of milk was held at 145 degrees for 30 minutes. Pasteurization did not sterilize the milk and it still needed to be refrigerated afterwards. It did greatly reduce the number of bacteria in the milk so the chance of bacterial illness was minimized and the shelf life of the milk was increased. High Temperature Short Time continuous processes were developed between 1920 and 1927 and for some time the ability of the HTST process to produce safe milk was questioned.

There is also a UHT (ultra High temperature) method where the milk is heated well above boiling under pressure for just a few second. This product is essentially sterile and does not have to be refrigerated until it is opened. For most continuous processing, a high temperature short time pasteurizer is used. The heat treatment is accomplished using a plate heat exchanger. High Temperature Short Time Process

History of Milk

History of Milk
The Holstein breed outnumbers all others used in the United States for the production of milk. Jersey and Guernsey breeds tolerate hot weather better than Holsteins, hence may be the predominant types used for the production of milk in hot weather areas. Some Ayrshire, and Brown Swiss or Shorthorn breeds are used in certain areas. Cow’s milk contains an average of 3.8 % fat, 3.3% protein, 4.8% lactose, 0.7% ash, and 87.4% water, Milk also contains vitamins and other nutrients in small amounts, making it the most complete of foods. The young of mammalians survive on it exclusively.

Cow milk was first used as human food in the Middle East. Goats and sheep were domesticated in the Middle East between 9000 and 8000 BC. Goats and sheep are ruminants: mammals adapted to survive on a diet of dry grass, a food source other useless to humans, and one that is easily stockpiled. Around 7000Bc, cattle were being herded in parts of Turkey.

Fermented products such as cheeses were discovered by accident, but their history has also been documented for many centuries, as has the production of concentrated milks, butter, and even ice cream. The use of cheese and butter spread in Europe, parts of Asia and parts of Africa. Domestic cows were introduced to the colonies o f Europe during the Age of Exploration.

Cattle were first brought to United States in the 1600s by the earliest colonies. By 1790, population centers such as Boston, New York, and Philadelphia had grown sufficiently to become an attractive market for larger scale dairy operations. To meet the increase demand, farmers began importing breeds if cattle that were better suited for milk production. At that time variety of machines for processing of milk was also developed.

In 1856, Gail Borden patented a method for making condensed milk by heating it in a partial vacuum. In 1863, Louis Pasteur developed a method of heating to kill the microorganisms that cause wine to turn into vinegar. Later this method was adapted to milk processing and known as pasteurization process. Milk was first delivered in bottles on Jan 11, 1878 and known as a Milk day.
History of Milk