EXTRACTION AND OPTIMIZATION OF DYEING CONDITIONS OF DYE OBTAINED FROM PURPLE SWEET POTATO ON COTTON FABRICS

Objective: This study aimed to isolate anthocyanidins from purple sweet potato (Ipomoea batatas) and to determine the optimum dyeing conditions for achieving maximum color yield and fabric affinity when dyeing cotton fabrics, as a sustainable alternative to synthetic dyes. Methods: Anthocyanidins were extracted from purple sweet potato using acidified ethanol to ensure pigment stability. Dyeing parameters including temperature (40–80 °C), pH (3–9), and dyeing time (30–90 min) were systematically optimized. UV–Vis spectroscopy was employed to identify anthocyanidins based on characteristic absorption peaks at 520–540 nm, while FTIR analysis was used to confirm the presence of functional groups associated with anthocyanidins and to assess structural integrity after extraction. Results: The UV–Vis spectra confirmed the presence of anthocyanidins through characteristic absorption peaks, while FTIR analysis revealed functional groups such as hydroxyl and aromatic rings, indicating that the extracted pigments remained structurally intact. Optimal dye uptake was achieved at a dyeing temperature of 80 °C and pH 3. Longer dyeing times (90 min) resulted in more uniform coloration on cotton fabrics. Conclusion: The results demonstrate that anthocyanidins extracted from purple sweet potato are effective natural dyes for cotton fabrics. Under optimized dyeing conditions, these pigments exhibit good color uptake and uniformity, indicating their strong potential as environmentally friendly and sustainable alternatives to synthetic dyes.