Niacin (Vitamin B3)
Ascorbic Acid (Vitamin C)
Carotene (Vitamin A)
Riboflavin (Vitamin B2)
Table 2.1: Typical nutritional value
per 100g of raw pitaya (Ariffin, 2008)
Antioxidant is a molecule that capable of slowing or preventing the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons from a substance to an oxidizing agent. Oxidation reactions can produce free radicals, which start chain reactions that damage cells. Antioxidants terminate these chain reactions by removing free radical intermediates, and inhibit other oxidation reactions by being oxidized themselves. As a result, antioxidants are often reducing agents such as thiols or polyphenols (en.wikipedia.org).