Trends of novel pretreatment methods for red pigments in food samples.

Abstract

While natural red colorants are generally safe, some synthetic red dyes have been linked to adverse effects, including allergenicity, neurodevelopmental toxicity, and confirmed carcinogenicity. Detecting trace levels in food is challenging due to complex matrices (proteins, lipids, natural pigments). Hence, efficient sample pretreatment is critical for ensuring food safety, underpinning analytical selectivity and reliability. This review provides a comprehensive overview of pretreatment methods for red pigments in complex foods, systematically comparing established techniques-liquid-phase microextraction, solid-phase extraction, solid-phase microextraction, and matrix solid-phase dispersion-and their modern variants, evaluating extraction efficiency, convenience, and environmental impact. Particular focus is on key innovations like integrating ionic liquids into dispersive liquid-liquid microextraction to enhance selectivity and minimize solvent use. By critically assessing each approach's strengths and limitations, it illustrates the trend toward greener, more efficient, and automated sample preparation technologies.