Development and optimization of the extraction process of natural dye from Tamarix aphylla (L.) Karst. Leaves using response surface methodology (RSM)

The extraction of colorant from Tamarix aphylla (L.) Karst. leaves was optimized using response surface methodology (RSM). The combined effects of extraction conditions (sodium hydroxide concentration, sample weight, and extraction time and temperature) on the total phenolic content (TPC) and color yield (K/S) were studied using three-levels three-factors Box-Behnken design. The optimum conditions for dye extraction were found to be 0.25 mol/l, 65 min, 88 A degrees C and 52.5 g/l for sodium hydroxide concentration, extraction time and temperature, and mass of the leaves powder respectively. The efficiency of extraction under these optimum conditions was found to be 1.12 g/l of phenolics and color yield equal to 11.20. Further, high-performance liquid chromatography analysis (HPLC) was used to identify the major phenolic compounds in the dye extract such as gallic acid, quercetin, luteolin, and kaempferon.