Hotter water ups antioxidants, increases red in tomatoes
There could be a new way to treat tomatoes after harvest that increases their nutritional value and makes them redder than ever for retailers and consumers.
In new research led by horticultural sciences professor Jeffrey Brecht, scientists from University of Florida Institute of Food and Agricultural Sciences discovered a hot water process that increases the antioxidant levels in the tomatoes, according to a news release.
Packinghouses in many states already use hot water treatments before shipping to retailers — to clean them and prevent possible diseases.
But the heat treatment in this study was more extreme.
“The idea is that tomatoes have a certain genetic potential for antioxidant production that isn’t always realized,” postharvest biologist Brecht said in the release. “That’s because tomatoes — all plants actually — produce antioxidants to deal with stress, and they produce more antioxidants the more stress they experience. Because we basically coddle tomatoes, the fruit doesn’t always realize its genetic potential for antioxidant production.”
The improved red color and nutritional value are benefits for consumers, he said.
Tomatoes in Florida are most commonly harvested at the mature green stage and ripened after packing.
Typically, packers heat dump-tank water — the gentlest way to transfer fruit from field bins or gondolas onto a packing line — to about 10 degrees Fahrenheit above the tomato pulp temperature.
They use warm water because it reduces the chances of decay, and the tomatoes stay in it for a couple minutes, Brecht said.
These scientists found a synergy between the new hot water treatment and high-temperature ethylene treatment on mature green tomatoes that is more ideal than current methods.
“We think that process could be modified to duplicate our hot-water treatment and improve the tomato quality,” he said in the release.