History of milk pasteurization

Pasteurization, the name is derived from that of Louis Pasteur, whose discoveries in the 1860s and 1870s demonstrated that heating liquids, especially wines, to fairly low temperatures, such as 60°C, improved the keeping quality during storage.

In the middle of nineteenth century, commercial winemaker approached Louis Pasteur to seek a solution of abnormal fermentation and subsequent spoilage of wines and beers. Pasteur studied the problem during 1864–65 and found that some microorganisms are the root cause of abnormal fermentation leading to early spoilage of wines and it can be prevented by heating the wine around 60°C, which kills these microorganisms.

William Dewes recommended heating milk in the home before feeding to infants some 40 years before Pasteur conducted his experiments. Dewes observed that if the milk was heated to boiling point and cooled quickly, the tendency to spoil was reduced. This method was successful in reducing infant morbidity and mortality rates.

Also preceding Pasteur was the contribution of Gail Borden who, in 1853, patented a process for heating and condensing milk under vacuum followed by addition of sugar for preservation.

In 1867 Pasteur applies heat to milk and reports the process postponed milk souring.

The first application of pasteurizing heat treatments to milk may have been performed by Franz von Soxhlet in 1886, who pasteurized bottled milk fed to infants.

The first commercial pasteurizer was introduced in Germany in 1882, but it was not until 1893 that a commercial unit was established in the U.S. for pasteurization of raw milk.

Gerber and Wieske pasteurized milk in bottles at 65°C for 1 h as early as 1888. The first commercial pasteurizer was made in Germany in 1882; pasteurization on a commercial scale quickly became common practice in Denmark and Sweden in the mid-1880s.

In Denmark and Sweden, commercial pasteurization of milk was common as early as the mid-1880s, due in part to the early recognition by Danish butter makers of its merits. However, cities in the United States were much slower to openly embrace pasteurization techniques.

In the early 1900s, in Arizona, Jane H. Rider "publicized the link between infant mortality and contaminated milk, and finally convinced the dairy industry to pasteurize milk."

The first pasteurized milk ordinance was published in 1924 in the November issue of Public Health Reports; pasteurization was defined as a heating process of not less than 142°F (61.1°C) for 30 min in approved equipment.

In 1956 minimum temperature for vat pasteurization was raised from 142°F of to 145°F of based on heat resistance of Coxiella burnetii. Based on University of California Davis studies in late 1940's 1966 FDA memorandum accepts dual stem (CIP) flow diversion device to be used in HTST systems.

Today, pasteurization is used widely in the dairy industry and other food processing industries to achieve food preservation and food safety.
History of milk pasteurization

History of Technology: Soft drink

History of Technology: Soft drink
Technology certainly played a large part in the growth of soft drinks in the second half of the twentieth century.

The development of cans, plastic bottles high speed packaging lines and improvement to distribution systems have been largely responsible for the increase in availability, the decrease in real term cost and the resultant increase in consumption.

The advent of of railways and large steam ships in the 1800s made transportation feasible and indeed drinks were exported from the UK to the USA as early as 1800.

The export trade continued to expand and by the mid-1800s significant trade was being done with far corners of the Empire.

This must have involved considerable cost and on a domestic basic the trade was on a much more local scale.

The industry evolved as a multitude of local businesses operating in a small geographical area, though some larger companies operated several production plants in different parts of the country.

The UK Bottlers; Year Book 1933 listed more than 2000 soft drink manufacturing companies but by 1983 the list had shrink to less than 400, and the number is now down to less than 100.

Likewise the number of bottling plants in the USA grew to reach a peak of 7920 in 1929, remaining fairly constant until around 1950 and then halved to 3727 by 1965 as improved productivity and distribution started to have a significant effect.

This having of the number of bottling plant took place over a period in which per capita consumption rose by over 60%.

The growth of cans and PET bottles at the expense of returnable glass has played a significant part in this continuing productivity improvement, which has been truly amazing.

As recently as 20 years ago a typical returnable glass bottle line producing, 300 bottles/min, required about 25 operating personnel.

Highly automated PET bottle blowing and filling operations have also improved production efficiencies significantly.

Other factors contributing to improved operational/ distribution efficiencies (both in time and cost) include:

• Use of shrink wrap in place of crates or boxes
• Micro-processor controlled equipment, for example, for palletisation
• Automated syrup room operations
• Centralized computer-controlled warehousing systems
• Automated bar-coding and traceability systems
  

History of Technology: Soft drink