Seasonal variations in the proximate composition of Pyropia yezoensis harvested along the western and southern coast of Korea

Abstract

Aim: Pyropia yezoensis is a widely consumed edible seaweed that contains substantial carbohydrates, proteins, lipids, amino acids and minerals. In this study, the proximate composition, amino acid content and mineral content of P. yezoensis were compared at two culture sites in South Korea (Goheung and Gunsan) during same time period. Methodology: This study followed AOAC methods for proximate composition. Amino acid and mineral were analyzed by amino acid analyzer and inductively coupled plasma. Result: The highest measured protein contents were 39.66 +/- 0.49% in December at Goheung and 38.77 +/- 0.59% in January at Gunsan. Proximate compositions did not differ significantly between Gunsan and Goheung. Among amino acids, isoleucine, leucine, threonine, lysine, histidine and valine were present at higher concentrations during November and December harvesting periods. The levels of Ca and P were higher in Pyropia at Gunsan from November to February compared with Pyropia at Goheung. Interpretation: Clear temporal and spatial variations were observed in amino acid and mineral contents, but not in proximate composition. Our study provides important information about the nutritive properties of P. yezoensis.