Researchers at the University of Seville's Food Colour and Quality Laboratory announced on Mar. 27 that different cooking methods for tomatoes and carrots can significantly change how well the body absorbs carotenoids, which are compounds known for their positive health effects.
The findings matter because carotenoids, such as α-carotene and β-carotene, are important nutrients that promote health and help prevent vitamin A deficiency, a serious nutritional problem worldwide. Cooking is sometimes overlooked as a way to increase nutrient absorption from vegetables.
According to the researchers, oven-cooked carrots showed a ninefold increase in total carotenoid bioavailability compared to raw carrots. For tomatoes, using either an air fryer at 190 °C for 10 minutes or a conventional oven at 180 °C for 20 minutes resulted in the highest bioavailability values—a significant improvement over raw tomatoes with a 1.5-fold increase. The study also reported dramatic increases in vitamin A precursor carotenoids: "the increases in the bioavailability of the vitamin A precursor carotenoids in tomatoes (α-carotene and β-carotene) ranged from 26 to 38 times and 46 to 71 times, respectively, compared with those in raw carrots." The researchers said this shows cooking can be an effective strategy against vitamin A deficiency.
The research further examined energy efficiency among cooking methods. Microwave cooking was found most efficient for carrots by reducing electricity use by up to 96% compared to ovens. For tomatoes, air frying achieved high nutrient availability while cutting energy consumption by about 80%. These results were published recently in Food & Function (2024) and Food Chemistry (2026).
The researchers said their work helps define 'sustainable cooking' from both nutritional and energy perspectives. They suggested that widespread adoption of these techniques could contribute to a more sustainable food system if used daily by households and establishments.
Carrots and tomatoes also contain phytoene and phytofluene—colourless carotenoids that accumulate in skin tissue where they may offer protection against ultraviolet radiation.
