Extraction of natural dye from petals of Flame of forest (Butea monosperma) flower: Process optimization using response surface methodology (RSM)

The uncontrolled discharge of synthetic dyes into the aquatic ecosystem is a global environmental concern due to their negative ecotoxicological effects. Dyes obtained from different natural sources have emerged as an important alternative to synthetic dyes. In this study, natural colorant from the petals of the Flame of forest (Butea monosperma) flower was extracted under different operating conditions such as extraction time (45–120 min), temperature (60–90 °C) and mass of the petals (0.5–2 g) by conventional extraction technique. Response surface methodology (RSM) with the help of Design Expert Version 7.1.6 (STAT-EASE Inc., USA) was used for optimization of the extraction process and evaluation of interaction effects of different operating parameters. The optimum conditions for dye extraction were found to be 153.65 min, 73.53 °C and 1.47 g for extraction time, temperature, and mass of the flower respectively. The efficiency of extraction under these optimum conditions was found to be 8813.67 mg L−1. Further, Fourier Transform Infrared Spectroscopy was used to identify the major chemical groups in the extracted dye.

► Natural dye extraction from Flame of Forest petals.
► RSM applied for studying the interaction effect of different operational parameters.
► The interaction effect of the experimental parameters established by contour plots.
► An empirical quadratic model equation developed for the extraction process.
► Experimental values showed good agreement with the values predicted by the model.