Proximate composition analysis posterior to the cryopreservation of Chaetoceros calcitrans

Abstract

Objective. The effect of cryopreservation on the proximate composition of microalgae Chaetoceros calcitrans was evaluated. Materials and methods. C. calcitrans was cultured and cryopreserved using 5% (v/v) dimethylsulfoxide as cryoprotectant. The freezing was controlled at a rate of 3°C/min, up to -60°C and then the microalgae were immersed in liquid nitrogen (-196°C). After storage in liquid nitrogen, microalgae were rapidly thawed out and subcultured. The percentage of proteins, lipids and carbohydrates was analyzed using absorption spectrophotometry and the organic matter was studied by gravimetric analysis. Results. There was no significant variation between the proximate composition of C. calcitrans cryopreserved and the controls (p>0.05). Conclusion. Our results show that, despite low cell recovery after the preservation of this organism at low temperatures, there is no apparent loss of nutritional characteristics caused by the storing process at low temperatures.

Keywords

• Diatom
• freezing
• nutrients
• storage viability