Articles
POTENTIAL NATURAL DYE WITH ANTIOXIDANT PROPERTIES FROM RED DRAGON FRUIT (HYLOCEREUS POLYRHIZUS)
Article number
875_62
Pages
477 – 486
Language
English
Abstract
This study aims to investigate the pigment extraction efficiency and stability in the dragon fruit, both from the pulp and peel in two different sets of experiment and the antioxidant properties in the pigments.
For the pigment extraction efficiency and stability from fruit pulp, best water: weight ratio was 1:1; best temperature observed was 100°C; best extraction method was using juice concentrate rather than water extraction method where results showed that betalain concentration was at least twice higher; and the best storing condition varied according to different storage conditions.
Both extraction methods exhibited stable pH reading after one week of storage.
The best condition to obtain highest betalain concentration from the peel was heating samples at 100°C; 5 min; and in a pH5 condition.
The HPLC analysis confirmed the presence of betanin in samples at a retention time of 11.4 min which corresponds to the retention time of the betanin standard used.
In the antioxidant properties study, the total polyphenol assay which expresses gallic acid as equivalent showed that there was 86.1 mg/g of total polyphenolic compound in 0.5 g of dragon fruit dry extract and the reducing power in increased from 0.178 to 2.365 in 0.03 to 0.50 g of sample.
The vanillin-HCl assay showed that the sample had an equivalent of 2.3 mg catechin equivalents/g dried extract while in the DPPH radical scavenging activity determination showed that the effective concentration (EC50) for dragon fruit was 2.9 mM vitamin C equivalents/g dried extract.
For the pigment extraction efficiency and stability from fruit pulp, best water: weight ratio was 1:1; best temperature observed was 100°C; best extraction method was using juice concentrate rather than water extraction method where results showed that betalain concentration was at least twice higher; and the best storing condition varied according to different storage conditions.
Both extraction methods exhibited stable pH reading after one week of storage.
The best condition to obtain highest betalain concentration from the peel was heating samples at 100°C; 5 min; and in a pH5 condition.
The HPLC analysis confirmed the presence of betanin in samples at a retention time of 11.4 min which corresponds to the retention time of the betanin standard used.
In the antioxidant properties study, the total polyphenol assay which expresses gallic acid as equivalent showed that there was 86.1 mg/g of total polyphenolic compound in 0.5 g of dragon fruit dry extract and the reducing power in increased from 0.178 to 2.365 in 0.03 to 0.50 g of sample.
The vanillin-HCl assay showed that the sample had an equivalent of 2.3 mg catechin equivalents/g dried extract while in the DPPH radical scavenging activity determination showed that the effective concentration (EC50) for dragon fruit was 2.9 mM vitamin C equivalents/g dried extract.
Authors
O.P.S. Rebecca, K.V. Harivaindaran, A.N. Boyce, S. Chandran
Keywords
antioxidant, betacyanin, dragon fruit, Hylocereus polyrhizus, natural dye
Online Articles (73)