## 2 Carotenoids and Betalains: Bioactivity and Health Benefits  
Carotenoids and betalains are among the most common natural pigments in nature. Carotenoids may be classified into carotenes (a-carotene, b-carotene and lycopene) and xanthophylls (lutein, zeaxanthin and b-cryptoxanthin). Both carotenes and xanthophylls contain hydrogen and carbon chains but differ in the presence of hydroxyl groups [14]. Carotenoids are generally used as natural food colors with yellow to red shades and antioxidants. They may also be applied as food supplements by exploiting their intrinsic properties, such as modulation of the immune system and prevention of the risk of cancer and cardiovascular disease, as well as precursors of vitamin A [16]. The demand for pure, stabilized, well-characterized and low-price natural carotenoids is constantly growing, also thanks to the possible positive effects on human health. Their market is estimated to grow from $1.5 billion in 2019 to $2.0 billion by 2026 [17]. Countless studies have been conducted to evaluate the health effects of carotenoids from vegetables, and most of them are shown in Table 1. [PERSON] et al. [18] reported that a balanced intake of carotenoids in ratios similar to those present in fruit and vegetable extracts could lead to a large synthesis of retinoids, which was more efficient than the single artificial carotenoid (even if used at high concentration). In addition, they are likely to restore the accumulation of fat and stimulate its use by the organism. Carotenoids may also act as natural colorants, as well as serve as a functional bioactive ingredient. In particular, the integration of carotenoids into the diet has shown several beneficial effects for health, such as the improvement of the immune system, an increase in antioxidant activity, the marked protective action against various types of cancer and the reduction of risk of cardiovascular disease due to their ability to control blood cholesterol levels [19; 20]. [PERSON] et al. [21] proved that carotenoid extraction from persimmon waste might be a good solution for obtaining antimicrobial compounds against foodborne methicillin-resistant _Staphylococcus aureus_ and as an anti-_Helicobacter pylori_. [PERSON] et al. [22] have reported antidiabetic properties associated with carotenoids extracted from capsicum fruits. This phenomenon may depend on the phytochemical and antioxidant properties and, in detail, on their ability to modulate carbohydrate digestion and enhance insulin secretion. The work of [PERSON] et al. [23] has shown that the by-products of baby carrots and cherry tomatoes (when transformed into both pulp and powder) are rich in bioactive compounds such as phenolics, carotenoids and tocopherols, and therefore, they have a high nutritional and functional value as additives. Furthermore, this study also demonstrated that the nutritional profile of these by-products is similar in bioactive terms to the profile of carrots and tomatoes that meet marketing standards. Moreover, the study of [PERSON] et al. [24] also demonstrated that the consumption of carrots as a potential source of fiber, phenolic compounds and carotenoids has been associated with a reduced risk of cardiovascular disease. This property is due to the ability (especially of carotenoids) to bind molecules such as cholesterol, reducing its availability in the body. Additionally, consuming these vegetables would help reduce blood LDL levels and the levels of short-chain fatty acids produced by colon bacteria. Other studies [25; 26; 27; 28; 29; 30; 31; 32; 33] demonstrating the health effects of carotenoids are summarized in Table 1.  
Betalains are molecules deriving from conjugated betalamic acid with cyclo-dopa (redviolet beta-cyanines) or with the amino groups of amino acids, amines or their derivatives (yellow betaxanthines) [16]. As indicated in Table 1, they are free radical scavengers and