Evaluating the cultivation status, growth rate, carrageenan content and quality of Kappaphycus alvarezii (Doty) in Vietnam

Abstract

Kappaphycus alvarezii farming in Vietnam is currently facing several practical challenges that have led to a decrease in area, seed availability, and output. The 2021-2022 survey shows that the area dedicated to farming has gradually diminished to approximately 345 hectares. The total production has also significantly decreased to around 700 dry tons per year. The cause of the decrease in farming area can be attributed to the lack of comprehensive planning, poor quality of seaweed seeds, and insufficient stability in commercial output. Research findings indicate that the growth rate of K. alvarezii remains relatively stable, with an average range of 3.43±0.36 to 3.67±0.42% per day. The carrageenan content ranges from 41.56±2.25 to 45.42±2.10% (based on the weight of clean and dry seaweed), while the gel strength ranges from 556.67±25.17 to 591.00±40.10 g/cm2, and viscosity ranges from 93.10±17.06 to 96.00±25.51 cP. The research indicated that the carrageenan content and quality of K. alvarezii fully comply with national standards for technical requirements of carrageenan used in food additives. This study also provided an overview of the current status of K. alvarezii farming and production in recent years, offering a scientific foundation
for evaluating and establishing a comprehensive master plan in Vietnam.