Vegetables and fruits not only contain essential nutrients but also valuable secondary plant compounds such as carotenoids, which belong to the fat-soluble color pigments. The most well-known is beta-carotene, which is converted into vitamin A in the body. Astaxanthin, lycopene, lutein, and zeaxanthin are also familiar to most people. Plants produce them as a defense mechanism, but they also have valuable properties for humans, serving, for example, as natural antioxidants.