Betalain extracts: Drying techniques, encapsulation, and application in food industry

Abstract

One of the important food additives used in the food industry is betalain, which is applied as a natural dye. Red beet is the most common resource of betalain. To increase its shelf life, encapsulation followed by drying is commonly carried out. However, betalain is a heat-sensitive pigment that is susceptible to degradation on thermal exposure. Moreover, drying could affect the color, shape, structure, nutrition, and content of other ingredients in betalain. This review paper provides a discussion of (1) various drying methods such as spray drying, freeze drying, vacuum drying, and their effects on the quality of the dried betalain products; (2) stability and properties of betalain pigment obtained by encapsulation using different carrier agents such as maltodextrin, gum arabic, starch, inulin, and protein; (3) several drying pretreatment and posttreatment processes to improve the recovery and stability of betalain such as extraction and optimum storage conditions. Additionally, a summary and future perspectives for further research are also provided in each section of drying methods.