University of Florida scientists have developed a tomato packed with significantly higher levels of vitamin A, a breakthrough that could help combat one of the world’s most widespread nutritional deficiencies.
In newly published research by Jingwei Fu, Denise Tieman and Bala Rathinasabapathi from UF’s Institute of Food and Agricultural Sciences (UF/IFAS), the researchers introduce fortified tomatoes with boosted beta-carotene—the compound the body converts to vitamin A.
“The levels of beta-carotene found in the improved tomatoes are more than those found in market tomatoes and in many beta-carotene-rich foods like kale and sweet potatoes,” said Rathinasabapathi, professor of horticultural sciences at UF/IFAS.
Vitamin A deficiency, which impairs growth, red blood cell production, immunity and eyesight, affects 345 million people across 79 countries. Children and pregnant women in impoverished societies are particularly vulnerable. Daily consumption of 50 to 100 grams of these tomatoes can efficiently address vitamin A deficiency, Rathinasabapathi said.
Fu, who led the research as a doctoral student under Rathinasabapathi’s direction in the UF/IFAS College of Agricultural and Life Sciences – and is now a post-doctoral assistant in the same lab — introduced CCS, a gene from the carotenoid synthetic pathway from peppers into tomatoes to increase beta-carotene. The researchers chose the tomato because it’s one of the world’s most popular vegetables, with annual production of 180 million tons worldwide.
Their research showed that the pepper gene worked to improve tomatoes’ nutritional value when it was transferred to different varieties of tomatoes.
To understand the function of a gene in peppers, scientists first turned off CCS, a gene involved in the synthesis of capsanthin and capsorubin, two pigments in red peppers.
“The pigments are good for people because they are excellent antioxidants, like the color you see in sweet potatoes or carrots,” Rathinasabapathi said. “After identifying the gene from that experiment, we expressed it in a tomato variety. The resulting plant had orange tomatoes — instead of red. The improved tomato had increased levels of pigments capsanthin, capsorubin and beta-carotene. This made the new tomato nutritionally valuable.”
In the next part of the study, researchers developed hybrid tomatoes by crossing selected varieties and the newly developed orange tomato. The resulting hybrids were nutritionally much more valuable in terms of beta-carotene, capsanthin and capsorubin levels than the originally developed tomato.
The fruit of these hybrids are also larger than the original varieties. In controlled experiments, the orange tomato yielded more fruit and had improved flavor volatile profiles when compared to fruit of unmodified controls. Beta-carotene, the orange pigment known in vegetables and fruits, is a provitamin A, which means the body converts it into Vitamin A, Rathinasabapathi said.
“In general, tomatoes accumulate lycopene — the red pigment — but not high levels of beta-carotene,” he said. “We can confidently say our improved tomatoes are nutritionally more valuable than commercially available tomatoes and some of the food material known for beta-carotene such as carrots and kale.”
This vitamin A-fortified tomato is the latest in a long history of discoveries UF/IFAS scientists have made to improve the fruit. Researchers have developed tomatoes that resist many diseases, heat and pests, including UF/IFAS Tasti-Lee®, a hybrid that’s very popular because it tastes so good.
