Studies have evidenced the biological properties of fucoxanthin and the commercialisation of various nutritional supplements based on seaweed extracts that claim high fucoxanthin content is constantly growing. However, it was demonstrated that fucoxanthin is highly susceptible to degradation, and in this context the need for simple and reliable analytical methods for fucoxanthin analysis is evident. This article presents a simple thin-layer chromatography (TLC) densitometric method for the determination of fucoxanthin from Undaria pinnatifida extracts and commercial formulations. Fucoxanthin was separated on TLC silica gel 60 F254 plates with acetone:n-hexane 6:4 v/v as mobile phase. Densitometric analysis was performed using the Image J image-processing program available online. Calibration data revealed good linear relationship (R(2) = 0.9955) between peak area and concentration of fucoxanthin. The repeatability was 2.0 (% CV), and intra-day and inter-day precisions were 1.5 and 2.0 (% RSD), respectively. The proposed method provides an inexpensive tool in preliminary evaluation of fucoxanthin-based products.
Keywords: Undaria pinnatifida; densitometric analysis; fucoxanthin; thin-layer chromatography.