Evaluation of Roselle (Hibiscus sabdariffa L.) Calyx Extract Stability for Intestinal Nematode Egg Staining

Abstract

Roselle (Hibiscus sabdariffa L.) calyx extract is rich in anthocyanin and it has been widely used as a natural colouring agent, for example as an alternative dye for eosin 2% in intestinal nematode egg staining. However, as a natural colour, the temperature and storage time are often altered anthocyanin activity. Therefore, the objective of this study was to investigate stability of Roselle calyx extract using various time and temperature storage and its staining properties on the intestinal nematode eggs. The Roselle calyx was extracted using maceration technique for ± 3 days and then made 80% concentration of extract. Extracted is stored within 1, 7, 14, and 21 evaluation days in room temperature (25°C) and cold temperature (4°C) for extract characterization, absorption of anthocyanin, pH, and staining observation. The result showed that natural extract from Roselle calyx stained intestinal nematode eggs and stable within 21 days storage in cold temperature (4°C).