Hylocereus belongs to the Cactaceae family and has recently gained attention because of its
nutraceutical value. To explore the use of Hylocereus peel as natural food color and food
preservative, the betacyanin, flavonoid, polyphenol content, and antimicrobial activity was
studied. 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 as
standard. Total polyphenol content was measured using the Folin- Ciocalteau method. All the
determinations were carried out on the methanolic extract of dragon fruit. Since the peel contains
a 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 be
158.6 µg/mg quercetin equivalents. The total betacyanin content was found to be 2.2mg/100g of
the peel. Since the extract is rich in antioxidants, its use as natural food color is desirable. The
dark 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 a
powerful antioxidant it has antimicrobial activity as well. The antimicrobial studies are also
promising as the test performed indicates no increase in microbial count in presence of peel
extract and for this, it's utility as food preservative was studied. Due to its desirable properties of
antioxidant and antimicrobial activities, the fruit peel can be exploited for its commercial
prospects as natural food color and food preservative.