Watermelon: nutritional value and health benefits of watermelon flesh. Watermelon is rich in carotenoids. Some of the carotenoids in watermelon include lycopene, phytofluene, phytoene, beta-carotene, lutein, and neurosporene. Lycopene makes up the majority of the carotenoids in watermelon. The carotenoid content varies depending on the variety of the watermelon.