Purple heart (tradescantia pallida) leaves anthocyanin extract as a natural dye powder/
Caylah C. Cuaresma, Andrea Shine C. De Jesus, and Germaine Ashly H. Moratilla.--
- Manila: Technological University of the Philippines, 2025.
- xii, 151pages: 29cm.
Bachelor's thesis
College Of Science.--
Includes bibliographic references and index.
Anthocyanins are used as natural pigments in various industries, due to the color palette they can produce from red to blue and purple. However, their stability is influenced by parameters such as pH, light, and temperature. This study examined the potential of anthocyanin pigments extracted from Purple Heart (Tradescantia pallida) leaves as a natural dye powder to provide an eco-friendly alternative to synthetic dyes. Anthocyanins were successfully extracted using 30% ethanol with 5% citric acid. Subsequent purification via liquid-liquid extraction and dialysis removed impurities, confirmed by a reduction in absorbance and a single spot (Rf = 0.525) using 6:3:1 (hexane:ethanol:ethyl acetate) solvent system in Thin Layer Chromatography. The purified extract was converted into a powder through freeze-drying, yielding an average of 0.782% and a moisture content of 0.34%. Characterization through pH-dependent color changes and Fourier-Transform Infrared (FTIR) spectroscopy identified petunidin, and malvidin derivatives, with prominent O-H, C=O, C-H and C-O functional groups. Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) revealed polydisperse particles and confirmed the
organic elemental composition of the dye powder. Furthermore, Ultraviolet-Visible (UV- Vis) and FTIR analyses showed progressive degradation under increasing temperatures
(30°C, 40°C, 60°C, 80°C) and light exposure, with a noticeable decrease in absorbance and peak intensities. When applied to pre-mordanted cotton fabrics using Copper sulfate (CuSO4) as mordant, the dye exhibited minimal staining (grayscale 4.5) but poor colorfastness to laundering, with significant color change (grayscale 1-1.5).