Growth rate, concentration, and quality of carrageenan in two strains of seaweed Kappaphycus striatus grown in Khanh Hoa waters

Abstract

In this study, two strains of seaweed Kappaphycus striatus (Payaka brown and Sacol brown) derived from Philippines after nearly 20 years of cultivation, were cultivated in Van Phong Bay and Cam Ranh Bay (Khanh Hoa, Vietnam) to re-evaluate the growth characteristics, concentration, and quality of carrageenan. The results showed that the ecological area affects the growth (fresh weight, growth rate, dry matter accumulation rate), content, and quality of carrageenan (gel strength and viscosity) of the two seaweed strains after 2, 4, 6, 8, 10, 12 weeks of cultivation. The highest biomass of both strains was reached after 8 weeks of cultivation in Van Phong Bay and 10 weeks in Cam Ranh Bay. The fresh weight, the dry weight, and the growth rate (343.33 g, 42.67 g, 1.30%.day^-1, respectively) of the Sacol brown strain were similar to that of the Payaka brown strain at the Van Phong Bay. However, the dry matter accumulation rate (12.45%) and the carrageenan content (24.50%/w) of the Sacol brown strain were highest when cultivated in Van Phong Bay. The growth rate, concentration, and quality of carrageenan in two seaweed strains in Van Phong Bay and Cam Ranh Bay were lower than before.