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Preserving Tomatoes for Year Round Taste

Preserving tomatoes for year-round taste and nutrition


Learn how tomatoes picked at peak ripeness are preserved to make delicious and nutritious sauces, soups, salsa and beverages all year long. #RealFood #Sustainability

My family eats tomatoes year-round. Unfortunately, here in the mid-Atlantic the quality and taste of fresh tomatoes is a hit or miss outside of the summer season. One week my salads will pop with the sweet, juicy, cherry tomato flavor and the next week they’ll fall short with a bland, mealy tomato. I rely on tomato paste, canned tomatoes, and prepared items like Prego® Italian saucesCampbell’s® Condensed Tomato soup and others to get me through the off season. How do these products deliver a fresh tomato flavor year-round? I reached out to Dr. Daniel Sonke, Director of Sustainable Agriculture at Campbell, to learn how we preserve over one billion pounds of tomatoes grown by family farmers every summer.

Lindsay: Why do we only harvest and process our tomatoes during the summer?

Dr. Sonke: We make our products year-round and need them to taste the same whether we make them in July or January. If we only relied on fresh produce, the flavor would vary drastically from one month to the next, just like what happens when you buy tomatoes out of season vs. in season. Our tomatoes are processed within hours of harvesting, and of course, we harvest in the mid to late summer when tomatoes taste their best.
Lindsay: What types of processed tomato ingredients does Campbell make?

Dr. Sonke: We make several types of tomato paste, as well as diced tomatoes. People are sometimes surprised to learn that different types of tomato paste are required to make different products from creamy-textured tomato soup to thick Prego® Italian sauces. Some tomatoes are better for dicing, while any of them can be used for paste.

Lindsay: I understand that we use most of our tomato crops to make tomato paste. Why is that our preferred tomato ingredient to use?

Dr. Sonke: Tomatoes are about 94% water and 6% solids. The solids in a tomato provide the sweetness and flavor of the vegetable. We concentrate our tomatoes into a paste to make transporting and storing them more efficient. If we only used formats like crushed, diced, or others, we would be using a lot of resources to transport and store water. Paste helps us use what we need, when we need it, without as much waste.

Lindsay: How do the tomatoes become tomato paste?

Dr. Sonke: After tomatoes are harvested, cleaned, and sorted, we use heat and physical agitation to make a tomato pulp. This would be like heating tomatoes on your stove and using a potato masher to break them down for a smoother consistency. After we break down the tomatoes, we put the pulp, which still has skins, seeds, and tomato solids, through an “extractor.” This is just a giant version of a home mixer attachment my family uses in our kitchen to separate peels and seeds when we make applesauce or homemade tomato sauce. At Campbell, the extractors separate the skins and seeds from the pulpy tomato solids and juice. We only use the solids and juice to make paste, but the skins and seeds get shipped off to be turned into animal feed by other manufacturers.

Lindsay: Do we add any other ingredients to help preserve the tomatoes?

Dr. Sonke: At this point in the processing, we heat up the paste and then rapidly cool it to prevent any microbial growth. We fill the paste into sterile bags and heat seal them. Similar to how you can your tomatoes at home, the heating and sealing is what preserves the food.

We add citric acid to our diced tomatoes and sometimes to our paste. This is like adding lemon juice to your canned tomatoes at home. A lower pH helps to make it last longer on the shelf. We also add calcium chloride to our diced tomatoes to help them stay firm. This helps them keep their texture and is what you would find in canned, diced tomatoes you buy in stores.

Lindsay: The process we use for making tomato paste and diced tomato ingredients sounds similar to what you would do at home. What are the biggest differences?

Dr. Sonke: The scale and the equipment we use. Otherwise, it is very similar to what you would do at home. My wife and I can Campbell tomatoes that don’t make it into the truck during harvest each year. A lot of what we do in our kitchen is like what happens in the plants, just on a much smaller scale.

We want consumers to understand how we make our products and the experts that guide us behind the scenes. This Q&A session with Dr. Sonke sheds light on how processing fresh tomatoes at peak ripeness allows consumers to enjoy consistently delicious taste and nutrition from the brands they know and love all year round.




Lindsay Watts, MS, RDN

Senior Nutrition Communications Specialist

Lindsay is a nutrition communications analyst at the Campbell Soup Company where she coordinates health professional and consumer communications. She also works with internal and external partners on retail health and wellness programs. Prior to her role at Campbell, Lindsay worked as an in-store retail dietitian. She received her Bachelor of Science in Nutrition and Dietetics from West Chester University and completed her dietetic internship with Pennsylvania State University. Lindsay received her Master of Science in Health Communications and Marketing from Boston University.

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