Seasonal Changes in Proximate and Bioactive Compounds of Brown and Red Seaweeds from İskenderun Bay, the North-Eastern Mediterranean Sea

Abstract

Proximate and bioactive compounds (total phenolic, flavonoid, chlorophyll-a and total carotenoid contents) of three brown seaweeds (Dictyota dichotoma, Padina pavonica, Stypopodium schimperi) and a red seaweed (Jania rubens) from the north-eastern Mediterranean Sea (İskenderun Bay) were investigated seasonally at three sampling sites. Seasonal variations were found for all of the parameters studied. The highest ash content was in J. rubens (77.7%) in the spring. The results showed that J. rubens is a rich source with respect to mineral content. D. dichotoma had the highest crude protein content, whereas S. schimperi contained the most lipids. Phenolics ranged between 34.6 - 107.0 mg GAE/g dw. The highest total phenolics were found in S. schimperi in the summer, and the lowest in P. pavonica in the spring. The flavonoid contents (9.05-10.6 mg QE/g dw) were higher in brown seaweeds than that in the red seaweed. Moreover, chlorophyll-a and carotenoids levels were highest in D. dichotoma (4.53 and 2.83 mg/g, respectively) during the autumn. The results revealed that the biochemical composition of the examined seaweeds showed significant changes depending on the species, location and seasons.

Keywords

• seaweed
• proximate composition
• bioactive compounds
• phenolics
• flavonoids