Anthocyanins and Other Polyphenols in Citrus Genus: Biosynthesis, Chemical Profile, and Biological Activity

Abstract

Abstract Citrus fruits are well-accepted by consumers all over the world because of their attractive colors, pleasant flavors and aroma, as well as for their well-known nutrition and health-promoting values. Citrus fruits are a good source of dietary antioxidants, which are vital in both health promotion and in the prevention and treatment of various human chronic and degenerative diseases. Flavonoids are the most abundant phenolic compounds found in Citrus fruits. Four types of flavonoids occur in Citrus species: flavanones, flavones, flavonols, and anthocyanins, with the latter group occurring only in blood oranges and in some of their hybrids. Moreover, these pigments are expressed in the young shoots and some floral tissues (new growth) of lemon, lime, and citron as well as in the peel (flavedo) of ‘ISA Red lemon’. Other phenolic compounds often found in Citrus are hydroxycinnamic and hydroxybenzoic acids. These compounds, and mostly anthocyanins, contribute to protect against certain cancers and cardiovascular diseases, reduce oxidative stress in diabetic patients, and protect DNA against oxidative damage.