Flower pigment analysis of <i>Melastoma malabathricum</i>

Abstract

Anthocyanin is among the permitted pigments that can be used for food colourant and having been considered a potential replacement for synthetic dyes. The objective of this study is to analyse the colour pigment, anthocyanin, that can be detected in flower and their stability in extracted form. All the analysed results will be used in the next study for the production of new food colouring material. From the observation, it shows that S3 flower developmental stage contains the highest anthocyanin concentration. Simple linear regression method was used to find the significant level correlating the anthocyanin concentration and storage time. Throughout the whole experiments, the extracted anthocyanin contents are quite stable. The graphs show a small degradation rate in the anthocyanin total concentration, except for the extracts that were exposed to the light where the degradation level reached more than 50%. At different pH values, the anthocyanin concentration decreased and the colour faded at higher pH. Extracts that were stored at high temperatures (31°C) showed higher degradation levels compared to the one kept at lower temperatures (25°C). From the study we find that the suitable storage condition for coloured anthocyanin pigments is in acidic solution (pH 0.5 and 1.0) kept in the dark and at low temperature (4°C).

Keywords: Anthocyanin, colourant, pigment, Melastoma malabathricum