Colour Extraction from Dragon Fruit (Hylocereus spp.) Peel

Background: The peels of dragon fruits, usually discarded as waste after fruit processing, contains betacyanin, a red-purple pigment that can be utilised to replace synthetic colours in food industry. This can be an efficient waste management system and can provide additional income to the farmers. Methods: Colour extracts were prepared from peels of both white and purple type dragon fruits by different maceration techniques viz., hydromaceration, maceration in ethyl alcohol, hydromaceration of freeze-dried peel, low temperature hydromaceration and low temperature ethyl alcohol maceration for 24 hours adopting 1:2 peel to solvent ratio. Extracts prepared by the two best extraction methods were subjected to ambient and low temperature (4 to 7°C) storage for three months for analyzing storage stability. Result: Hydromaceration of purple dragon fruit peel produced extracts with the highest betacyanin content. Highest total antioxidant activity was found in extracts prepared by low temperature hydromaceration of purple dragon fruit peel. Hydromaceration of purple- fleshed dragon fruit peels for 24 hours using 1:2 peel solvent ratio and storage at low temperature of 4 to 7°C can be recommended as the best maceration method for betacyanin pigment extraction.