Abstract: Carotenoids is one of the major classes of functional components in wolfberry. Total carotenoid content and composition are generally analyzed by colorimetry and high performance liquid chromatography (HPLC) after organic solvent extraction; however, these methods are complicated, time-consuming and expensive. The paper aims to analyze the relationship between skin color characteristics with carotenoid composition in wolfberry for the purpose of establishing a quick method for estimating the carotenoid composition and contents of wolfberry. The color of nine different accessions was quantitatively analyzed with a CM-5 colorimeter, and the relationships between the color values and carotenoid contents were discussed. The results showed that the color of wolfberry peel differed obviously among accessions. Total carotenoid content was correlated significantly positively with redness (a) but negatively with chromaticity (h) (P < 0.05). Brightness (L) and h were positively correlated with zeaxanthine content, and a and saturation (c) were positively correlated with zeaxanthin dipalmitate content. Accordingly, the content and composition of carotenoids in wolfberry could be conveniently determined by instrumental measurement of skin color. The method was simple and without the use of organic solvent and could provide a theoretical and technical basis for wolfberry breeding and quality evaluation.

Key words: wolfberry, color value, carotenoids, zeaxanthin dipalmitate