Anthocyanin is a water-soluble pigment, which can change color with the acidity and alkalinity of cell fluid. Cell sap is red when it is acidic, and blue when it is alkaline. Anthocyanins are one of the main pigments that make up the color of petals and fruits. It is produced by phenylpropanoid pathway and flavonoids biosynthetic pathway. The factors that affect the coloration of anthocyanins include the structure of anthocyanins, pH, * * * coloration, etc. The color of pericarp is influenced by internal and external factors and cultivation techniques. Light can increase anthocyanin content; High temperature will degrade anthocyanins. Anthocyanin is a secondary metabolite of plants and plays an important role in physiology. The colors of petals and fruits can attract animals to pollinate and spread seeds (Stintzing and Carle, 24). It is commonly found in the tissues of flowers and fruits, and in epidermal cells and lower epidermis of stems and leaves. The market price of some fruits is determined by the color depth. Anthocyanins belong to flavonoids in phenolic compounds. The basic structure contains two benzene rings, which are connected by a unit of 3 carbon (C6-C3-C6). Anthocyanins are produced through phenylpropionic acid pathway and flavonoid biosynthesis pathway, and are catalyzed by many enzymes. There are six aglycone, namely pelargonidin, cyanidin, delphinidin, peonidin, petunidin and malvidin. Anthocyanins show different colors due to the number of hydroxyl groups (-OH), methylation, glycosylation, sugar types and connection positions (Fan Heqiu, 1998). The expression of color is influenced by the change of biochemical environmental conditions, such as anthocyanin concentration, * * * color effect and pH value in fluid cells (Clifford, 2). The purpose of this paper is to understand the factors affecting anthocyanin biosynthesis, so as to serve as a reference for field cultivation and management.
orange and yellow are the functions of carotene. β -carotene was discovered in carrot in 191, and then two other isomers of carotene were discovered, namely, α, β and γ isomers. In 1958, β -carotene was patented (US2849495, Aug. 26, 1958, patentee: Hoffmann La Roche). At present, β -carotene is mainly extracted from the ocean, and it can also be artificially synthesized. Details:
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