Changes in phenolic composition and antioxidant activities of the edible halophyte Crithmum maritimum L. with physiological stage and extraction method

Most antioxidant phytochemicals isolated from higher plants are polyphenols exhibiting different biological activities. Previous studies have shown that plant phenolic contents and antioxidant activities depend on several factors, mainly environmental conditions, and post-harvesting procedures. The present study aims to assess the influence of these interfering factors on phenolic composition and antioxidant activities (DPPH test, reducing power) of Crithmummaritimum L., a promising food halophyte which attracts an increasing interest in recent years. Results showed that the summer plants (reproductive stage) were richer on phenolic compounds than spring ones (vegetative stage), and consequently exhibited higher antioxidant activities. The comparison of two extraction methods showed that maceration extracts contained greatest amounts of phenolic compounds, while soxhlet ones exhibited higher antiradical and reducing power capacities. Besides, the analysis of variance disclosed that the effect of extraction method (E) was the predominant contributor to these antioxidant properties than the physiological development stage (D) and their interaction (E × D). Chromatographic characterization of C. maritimum phenolic composition using the RP-HPLC revealed the presence of phenolic acids and flavonoids with epigallocatechin as major component. Almost all of the identified compounds were described in the literature as interesting bioactive natural substances that may be used in several fields, such as nutraceuticals, cosmetics and agro-food industry.