Betacyanins from Hylocereus undatus as natural food colorants

Abstract

Hylocereus undatus is an epiphytic cacti with brightly colored fruits. These fruits, known by various names such as Dragon fruit, Pitaya or Strawberry cactus are harvested as fruit crops in countries such as Vietnam, Australia and in South and Central America. The fruit peel contains naturally occuring, non-toxic red pigments known as betacyanins. The feasibility of employing the fruit peel as a source of natural colorants for coloring foods was investigated in this project. Compared with betacyanins from beet root, presently the only commercially available betacyanin-based food colorant, betacyanins from H.undatus (Vietnam) demonstrated superior shelf-life even in the absence of refrigeration. Stability under commonly encountered food processing conditions was also demonstrated with the exception of exposure to elevated temperatures. Thus, favorable properties for longer and less costly storage was demonstrated. Immense potential as such, exists, for the developement of commercial natural food colorants from such pigments.