Philip Nelson’s Aseptic Bulk Storage Revolutionized Global Food Trade

In 1991, the Institute of Food Technologists ranked aseptic processing and packaging No, 1 among the top 10 innovations in food technology–ahead of juice concentrates, safe canning processes, freeze-drying, and food fortification. In 1995, Dr. Nelson was awarded the IFT’s prestigious Nicholas Appert Award, named after another food industry pioneer who was spotlighted in the February/March 2011 issue of Food Quality. Dr. Nelson served as IFT’s president from 2001 to 2002. While his name is often associated with pioneering work in aseptic processing and bulk storage, he credits other food safety pioneers who preceded him. They include C. Olin Ball, who started studying aseptic processing in 1927 at the American Can Company (see Food Quality June/July 2011 issue), and the developers of the Martin-Dole process, invented at the Dole Engineering Company in the 1940s.

The discoveries made in Dr. Nelson’s Purdue lab, along with his work with companies, dramatically transformed the vegetable and fruit packing industry from a fresh pack system where produce was produced once a year into a remanufacturing industry where products could be made year round from vegetables and fruits stores in large containers. Notably, with orange juice, bulk aseptic storage and transportation made possible the wide-scale distribution of not-from-concentrate juice.

At Purdue, Dr. Nelson’s first industry research sponsor was Enerfab, an engineering company in Cincinnati, Ohio, which made tanks for the beer industry. “While the Martin-Dole process was for small containers, mine was aimed at a large, 1,000-gallon container, though I started with a 100-gallon container in the lab,” Dr. Nelson explained. With student labor to help get the tomatoes aseptically processed and into the tank, Dr. Nelson was able to quickly move to larger and larger tanks—from 15,000-gallon tanks for a Pennsylvania company to tanks holding a couple of million gallons for Tropicana in the 1980s.

“Tropicana wanted to see if my technology would work with orange juice. That’s when not-from-concentrate became popular,” he said. He also worked with Brazilians on half million-gallon tanks that could be carried on ships worldwide.

“The key technology is aseptic processing, with sterilized containers and products made sterile outside the container,” he said. “That made bulk storage possible.” Today, some citrus tanks are six stories tall and six stories wide.

Dr. Nelson said that because he was dealing with acidic foods such as tomatoes, he tested five different tanks with different linings and similar construction in the lab. He also looked into refrigeration, finding that it helps to protect the flavor as well as the vitamins. The contents underwent mild pasteurization before nitrogen was added. When stored at 40°F, the contents would keep for a year, he said. “The product is made just-in-time for the market,” Dr. Nelson explained.

Dr. Nelson credits rapid testing for improving food safety.

Bringing Food to the Developing World

As his pioneering technology began to be used in many developing countries, it became clear that it significantly increased the availability and accessibility of food. According to his World Food Prize biography, Dr. Nelson was part of a National Academy of Sciences team that traveled to India in the 1970s to study food spoilage, which at the time affected up to 50% of all food produced in the country. That visit prompted Dr. Nelson to start exploring ways for his technology to be used in developing countries.

“In India, the loss after harvest at the time was 10% to 30% of products such as grains, rice, fruits, and vegetables. Up to 50% of mangoes were lost,” Dr, Nelson said. “In 2009, they were still losing that amount.”