A Key Figure in Food Safety

Mention the name Louis Pasteur (1822-1895), and most people think of the pasteurization process he invented to prevent beverage spoilage. But Pasteur was a true renaissance man, researching, teaching chemistry and physics, and ultimately making discoveries that revolutionized fields such as agriculture, hygiene, and industry.

Often seen as the first modern microbiologist, Pasteur produced the first rabies vaccine, contributed to the founding of medical microbiology with his germ theory of disease, helped solve the mystery of diseased silkworms in mid-19th century France, and invented lab instruments to advance his research. He’s even credited with disproving the outdated theory of spontaneous generation, in which living organisms were thought capable of springing forth from nonliving matter. But, most importantly to the food and beverage industries, Pasteur’s discoveries of the roots of food spoilage and pasteurization helped to bring food safety to where it is today.

“This was a revolutionary idea,” according to Purnendu Vasavada, PhD, food safety specialist in the University of Wisconsin-River Falls Department of Animal and Food Science. “He made an unparalleled contribution in the history of food safety.”

Pasteurization, the process named after Pasteur, applies heat for a specified time to destroy human pathogens in foods and beverages to prevent spoilage.

“Pasteur found that microorganisms were the cause of spoilage in milk and other products such as wine and beer,” said Aaron L. Brody, PhD, president and CEO of the consultancy Packaging/Brody Inc., Duluth, Ga. “Pasteur used a microscope to identify the fact that microorganisms were present. Not much was known in the body of science at that time.”

Dr. Brody called Pasteur the foundation stone in the food safety industry. “If we didn’t know microorganisms were there and that they were the cause of a large percentage of food spoilage, then there would have been no further movement [in the field],” he added. “Nicolas Appert [a confectioner who worked 100 years before Pasteur and discovered that heat and airtight bottles could preserve food—see “The Father of Food Preservation,” Food Quality, February/March 2011] blindly did it without knowing why it worked. Pasteur figured out why it worked. It was seminal work, the microbial theory.”

Later, in 1894, Samuel Cate Prescott and William Lyman Underwood recognized that surviving microorganisms were the cause of spoilage in canned food. “I have a hunch Pasteur’s work was used as the basis for Prescott’s work,” said Dr. Brody. His research also influenced canning and other packaging research and use—and continues to do so.

“The diversity of his research, the brilliance of his intuitions, the rigor of his experimentations, and the importance of the results he obtained dramatically advanced both science and its techniques,” said a document produced by the Pasteur Foundation in New York.

Nonetheless, he didn’t apply his germ theory to all products, according to Dr. Brody, but only to those that were commercially valuable products in France at the time, like wine.

A Storied Career

Pasteur was born in Dole, France, on Dec. 27, 1822, to a poor tanner. When he was 5, his family moved to Arbois. In 1839, he attended high school at the College Royal in Benancon and received a baccalaureate in letters in 1840 and a baccalaureate in science in 1842, according to information provided by the Pasteur Foundation. In 1843, he was admitted to the Ecole normale supérieure, and he attended the chemistry courses of noted chemist Jean-Baptiste Dumas at the Sorbonne. In 1844, German scientist Eilhard Mitscherlich found that tartaric and paratartaric acids have the same chemical composition and form but affect polarized light differently, a discovery that started Pasteur’s scientific research career, according to the Pasteur Foundation.