Abstract:Red beet is a kind of edible vegetable with high nutritional value, which contains a large amount of betalains. Betalains are water-soluble, nitrogen-containing quaternary amine alkaloid with a core structure of betalamic acid. According to the chemical structure, betalains are divided into betacyanins and betaxanthins. As a kind of edible natural pigment, betalains have been applied to a lot of foods, however, their applications in some foods, nutritional health foods and cosmetics are limited owing to their poor stability. The composition and structure of betalains were reviewed, the effects of pH, light, temperature, oxygen and degrading enzymes on the content and color of betalains were discussed in details. And it was also summarized that the chemical changes occurred at easy degradable positions of betacyanins for deglycosylation, decarboxylation, dehydrogenation, aldimine bond hydrolysis and isomerization. This review aims to provide the references for further study on the stability of betalains and to expand the application fields of red beet and betalains.
