Characterization of dragon fruit (Hylocereus undatus) antioxidative components to explore their utility as natural food additive.

Abstract

Hylocereus belongs to the Cactaceae family and has recently gained attention because of itsnutraceutical value. To explore the use of Hylocereus peel as natural food color and foodpreservative, the betacyanin, flavonoid, polyphenol content, and antimicrobial activity wasstudied. The total betacyanin content was determined using the method described by Lim et al.The total flavonoid content was determined by using the AlCl3 method using quercetin asstandard. Total polyphenol content was measured using the Folin- Ciocalteau method. All thedeterminations were carried out on the methanolic extract of dragon fruit. Since the peel containsa high quantity of antioxidative compounds it is a very rich source of antioxidants.The concentration of flavonoid content of the methanolic extract of dragon fruit was found to be158.6 µg/mg quercetin equivalents. The total betacyanin content was found to be 2.2mg/100g ofthe peel. Since the extract is rich in antioxidants, its use as natural food color is desirable. Thedark color due to betacyanin increases the aesthetic appeal of the food when used as a food color.It is not only safe to consume but it also helps in improving the quality of food. Besides being apowerful antioxidant it has antimicrobial activity as well. The antimicrobial studies are alsopromising as the test performed indicates no increase in microbial count in presence of peelextract and for this, it’s utility as food preservative was studied. Due to its desirable properties ofantioxidant and antimicrobial activities, the fruit peel can be exploited for its commercialprospects as natural food color and food preservative.