Effect of Physicochemical Process Variables on Natural Indigo Dye Production from <i>Strobilanthes cusia</i> Leaves by Response Surface Methodology

The recovery process of indigoid compounds involves enzymatic hydrolysis indigo precursors continued by oxidation reaction to synthesize pigment. purpose this research was evaluate the effect physicochemical variables, i.e., temperature, time, and pH aeration, on yield from Strobilanthes cusia leaves. Small leaf pieces were immersed in distilled water heated at temperatures (40, 50, 60 °C) duration (1, 2, 3 h). extract aerated different pHs (8, 10, 12) form product. concentration quantified through a visible spectrophotometer high-performance liquid chromatography (HPLC). optimized condition for production studied using response surface methodology (RSM). Temperature, interaction between temperature time significantly affected yield. conditions extraction dyes determined be °C 1 h 8 maximizing On that condition, HPLC 1.15% (w/v) which lower than spectrophotometry. By spectrophotometric analysis, actual content 1.68% optimum close predicted 1.77% RSM.