Análise comparativa da qualidade da carragenina obtida da alga Kappaphycus alvarezii em estados fresco e seco cultivada na Ilha de Inhaca - Maputo

Abstract

This study analyzed the quality of carrageenan extracted from the marine alga Kappaphicus alvarezii in different states (fresh and dry) using an alkaline extraction method with NaOH. The research involved the collection of algae samples in both conditions, followed by processes of extraction and purification of carrageenan. The results revealed significant differences in the physical and chemical properties of carrageenan between fresh and dry samples. The dry sample showed a significantly higher yield (57.09%) compared to the fresh sample (2.70%), suggesting that the removal of water during drying directly impacts the amount of carrageenan obtained. Additionally, carrageenan from the dry sample demonstrated superior gelation properties, solidifying rapidly at room temperature. In contrast, carrageenan from the fresh sample required cooling to -16°C for 20 minutes to achieve proper gelation. Regarding viscosity, the carrageenan solution from the dry sample exhibited high viscosity, while that from the fresh sample showed average viscosity. Both samples showed stability in terms of pH, with values of 12.31 for carrageenan from the dry sample and 12.06 for carrageenan from the fresh sample. This suggests that the initial condition does not directly influence the stability of carrageenan in relation to pH. These findings underscore the importance of the initial condition of the alga in carrageenan production, not only in terms of yield but also in its physical properties such as gelation and viscosity