Green ultrasound-assisted extraction and life cycle assessment of lutein from marigold flowers using biocompatible surfactants

Abstract

Abstract The objective of this work is to extract lutein from marigold petals by the ultrasound assisted extraction employing surfactant based aqueous solution. In this study the effect of various parameters i.e. different biocompatible surfactants, temperature, extraction time, pulse mode (ON/OFF), ultrasonicator power, solid/liquid (S/L) ratio, surfactant concentration were investigated. Under the optimum conditions (temperature: 35 °C, extraction time: 20 min, pulse mode (ON/OFF): 20 s ON/OFF, surfactant concentration: 1 % (v/v), S/L: 7.5, ultrasonicator power: 370 W), the maximum lutein content of 12.18 ± 0.39 mg/g was obtained. Further, the comparative study was done for the conventional extraction (CE) and the ultrasound assisted extraction (UAE), both using surfactants aqueous solution as solvent for the extraction of lutein. The results revealed that the amount of lutein obtained using UAE method was notably higher than the CE method. Furthermore, CE and UAE methods were compared in terms of their environmental impact by life cycle assessment approach. Global warming potential (GWP) was found to be lower for UAE (0.91 kg CO2/kg of lutein extract) than CE (1.55 kg CO2/kg of lutein extract). An antioxidant activity of lutein extract was studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH). The results revealed that lutein can be extracted by UAE without affecting the antioxidant activity of lutein extract. The aforesaid results suggest that UAE employing surfactant based aqueous solution method is suitable for the extraction of lutein from marigold petals.