Rapid green microwave assisted extraction of lutein from Chlorella sorokiniana (NIOT-2) – Process optimization

• Published in: Food chemistry Vol. 372; p. 131151
• Main Authors: Mary Leema, J.T., Persia Jothy, T., Dharani, G.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.03.2022
• Subjects: Lutein; MAE; Microalgae; Process optimization; Purification; SEM; XRD; Process optimization; Purification; KOH; PTFE; Lutein; UHPLC-MS; Microalgae; XRD; RSM; MAE; ANOVA; AMD; SEM
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.131151

•A green process for microwave assisted extraction (MAE) of lutein from marine microalgae was developed.•Optimization was achieved using response surface methodology (RSM).•Optimized process augmented the lutein yield fold 3.26 fold and reduced the energy requirement 6 fold.•Purification process developed improved the purity of lutein from 39.39 to 90.73%. Chloropycean microalgae are looked up as a prospective alternate source for the production of xanthophyll carotenoid lutein. Despite, the market significance and multitude of nutraceutical applications of lutein commercial production from microalgae still remains a challenge due to the prohibitive downstream cost. This necessitates innovative less energy intensive, high lutein yielding green processes. The present work presents a comprehensive study on the rapid green microwave assisted extraction (MAE) of lutein from marine chlorophycean microalgae Chlorella sorokiniana (NIOT-2). The process parameters of microwave assisted alkali pre-treatment like exposure time (ET), alkali concentration (AC) and solid (biomass): liquid (aqueous Potassium hydroxide-KOH) ratio (S: L ratio) were optimized using single factor and response surface method (RSM) experiments. The optimized conditions for microwave assisted alkali pre-treatment (ET:1.47 min; AC: 8.16 M KOH and S:L ratio of 36.8:1 (mg/mL) augmented the lutein yield (20.69 ± 1.2 mg/g) 3.26 fold when compared to conventional extraction (6.35 ± 0.44 mg/g). Lutein extracted using optimized MAE conditions was purified and characterized. Visualization of the MAE extracted algal biomass using Scanning electron microscope confirmed the effective cell disruption. X-ray diffraction (XRD) analysis of microwave assisted alkali treated biomass (83.85%) revealed a significantly higher crystallinity index when compared to untreated control (17.28%). MAE pre-treatment can thus be propounded as a suitable process for lutein extraction from marine microalgae due to its amalgamated rapidity, homogenous heating, less energy intensiveness and high extraction yield.