Biochemistry and Molecular Biology of Carotenoid Biosynthesis in Chili Peppers (Capsicum spp.)

Abstract

Capsicum species produce fruits that synthesize and accumulate carotenoid pigments, which are responsible for the fruits’ yellow, orange and red colors. Chili peppers have been used as an experimental model for studying the biochemical and molecular aspects of carotenoid biosynthesis. Most reports refer to the characterization of carotenoids and content determination in chili pepper fruits from different species, cultivars, varieties or genotypes. The types and levels of carotenoids differ between different chili pepper fruits, and they are also influenced by environmental conditions. Yellow-orange colors of chili pepper fruits are mainly due to the accumulation of α- and β-carotene, zeaxanthin, lutein and β-cryptoxanthin. Carotenoids such as capsanthin, capsorubin and capsanthin-5,6-epoxide confer the red colors. Chromoplasts are the sites of carotenoid pigment synthesis and storage. According to the most accepted theory, the synthesis of carotenoids in chili peppers is controlled by three loci: c1, c2 and y. Several enzymes participating in carotenoid biosynthesis in chili pepper fruits have been isolated and characterized, and the corresponding gene sequences have been reported. However, there is currently limited information on the molecular mechanisms that regulate this biosynthetic pathway. Approaches to gain more knowledge of the regulation of carotenoid biosynthesis are discussed.

The Biochemistry and Antioxidant Properties of Carotenoids

“…Carotenoids which colors vary from light yellow to dark red stemming from the double bonds are soluble in organic solvents and oils like other lipids [10].…”

“…Carotenoids are found in red-, yellow-, and orangecolored fruits and vegetables as well as in all green leafy vegetables [10].…”

Development of an Advanced HPLC–MS/MS Method for the Determination of Carotenoids and Fat-Soluble Vitamins in Human Plasma

“…Carotenoids, xanthophylls and carotenes are natural fat-soluble, red, yellow and orange pigments characterized by a wide distribution, structural diversity and numerous physio-chemical and biological properties [9]. Particularly due to their antioxidant activity, carotenoids have been the subject of many studies [10,11,12,13,14]. To date, over 700 carotenoid compounds have been identified in various natural sources, and 40 to 50 of these are usually consumed in the human diet [15,16].…”

Physicochemical characterization and bioactive compounds of stalk from hot fruits of Capsicum annuum L.

“…The yellow-orange colors of pepper fruits are mainly due to the accumulation of α-and β-carotene, zeaxanthin, lutein and β-cryptoxanthin. Capsanthin, capsorubin and capsanthin-5,6-epoxide are responsible for the deep red colors [14]. Carotenoids possess a range of important biological activities.…”