# Continuous Liquid–Liquid Extraction of High-Purity Lutein from Chlorella vulgaris via Centrifugal Partition Chromatography: Utilizing Limonene as Renewable Solvent for Microalgae Biomass Valorization

## TL;DR

A new eco-friendly method using limonene to extract high-purity lutein from Chlorella vulgaris microalgae was developed.

## Contribution

The study introduces limonene as a renewable solvent in centrifugal partition chromatography for continuous lutein extraction.

## Key findings

- Limonene-based extraction achieved high-purity lutein in a single run.
- Limonene is a sustainable alternative to n-hexane with minimal environmental impact.
- The method allows continuous extraction without interrupting the process.

## Abstract

In this study, an efficient and eco-friendly method was developed for continuous liquid–liquid extraction of lutein from microalgae Chlorella vulgaris. By employing a limonene-based biphasic liquid system, high-purity lutein was successfully obtained from the crude extract in a single run via centrifugal partition chromatography (CPC). Evaluation and optimization results demonstrated that limonene could effectively serve as a replacement for n-hexane as the solvent system for lutein extraction, exhibiting natural renewability and minimal environmental impact. Furthermore, the elution–extrusion operation mode was employed to fully exploit the liquid nature of the stationary phase in the extraction process, allowing for continuous sampling and separation without interruption. This proposed protocol offers a sustainable and environmentally friendly alternative for extracting valuable ingredients from microalgae biomass, demonstrating its potential as a scalable solution for producing lutein-enriched ingredients applicable to functional foods and nutraceuticals.