Keeping Botulism Out of Canned Foods

Those of us old enough to remember will recall the frightening episodes of botulism in the United States from consumption of improperly processed canned foods during the 1960s and early ‘70s. Particularly frightening was the fact that many cases were traced to the consumption of commercial products manufactured by reputable firms, in which the consuming public had placed its trust.

Among the products implicated at that time were canned vichyssoise soup from New Jersey, canned mushrooms from Pennsylvania, canned black olives from California, and canned salmon from the Pacific Northwest.

That was nearly 35 years ago, and the last reported outbreaks related to botulism from canned foods were more than 25 years ago, according to FDA. This dearth of bad news is no accident; it is a success story begging to be told, that we will summarize here. At the top of the credit for this success story is the Food and Drug Administration, for the leading role it has played (and continues to play) in its regulatory responsibility for the safety of commercially processed foods. Credit also goes to the new breed of food technologists and engineers who bring their combined experience and powerful mathematical tools to advance the science and technology of thermal processing to everyone’s benefit.

Findings from the extensive FDA investigations of those early botulism outbreaks led to promulgation of the FDA Low-Acid Canned Food (LACF) regulations, with which the food canning industry must comply. Much credit must also go to the U.S. food canning industry and related equipment, consulting, and service supplier industries that chose to embrace these new regulations with enthusiasm, appreciation, and respect.

Compliance with and enforcement of these regulations required a new way of thinking and mode of operation on the part of both industry and government, reflected largely by decisions to place better trained and educated professionals in charge of thermal process operations. The need for the necessary knowledge and training spurred leading universities to offer related workshops and short courses, and to support research activities aimed at discovering new and better ways to ensure safety and quality of canned foods.

These activities attracted a new breed of food technologists and engineers, who introduced the application of mathematical models capable of simulating the complex mechanisms of fluid mechanics, thermodynamics, and heat transfer involved in thermal processing of canned foods. Application of these models to thermal process optimization and control (e.g., Simpson et al., 2006) has resulted in increased safety assurance of sterilized canned foods to the consuming public with maximum quality at lower cost.

However, continued diligence is still needed, especially in this new age of globalization with promotion of free trade. The quantity of canned foods from foreign manufacturers entering U.S. markets has increased nearly 40% over the past 4 years, according to FDA. These manufacturers must also comply with the LACF regulations. Although most of these foreign manufacturers are well aware of the need to comply, many lack the knowledge of how to comply. Again, we commend FDA for its valiant efforts to address this issue. FDA launched a series of Low-Acid Canned Food conferences in South America, beginning with Peru in June 2005, followed by a similar conference in Colombia in September. Further conferences are being scheduled for Ecuador, Chile, and Brazil in 2006.

The purpose of the conferences was to provide technical assistance to strengthen capacity in each country’s public and private sectors for this important class of food products. The conferences involved the establishment of a public and private coalition that was briefed on FDA findings. Each conference also included a 2-day workshop at cooperating canneries. This allowed the participants to conduct heat distribution and penetration tests on commercial products with production retorts.

We, along with other food engineering colleagues within the host countries, have had the privilege of participating in the first two conferences. We have seen firsthand how FDA is hard at work keeping botulism out of our food supply.

Art Teixeira ([email protected]) is Professor, Dept. of Agricultural and Biological Engineering, University of Florida. Sergio Almonacid ([email protected]) and Ricardo Simpson ([email protected]) are Professors, Dept. of Chemical, Biotechnological, and Environmental Processes, Universidad Técnica Federico Santa María, Chile. Authors Teixeira and Simpson are Professional members of IFT.

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