Effect of different drying methods on total lipid and fatty acid profiles of dried Artemia francis-cana biomass

Abstract

Frozen Artemia biomass were dehydrated by outdoor sun drying and three indoor drying techniques which consisted of convective hot air drying (HA), intermittent microwave combined with convective hot air drying (MWHA) and oven drying at temperatures of 50, 60 and 70°C. The aim of this study is to evaluate the effect of different drying techniques at different temperatures on the contents of total lipid and fatty acid profile of Artemia biomass. The results showed that among three indoor drying techniques, the shortest drying times (57-74 min) were observed in MWHA followed by HA (380-480 min) and oven drying (480-1320 min), respectively, while sun drying showed the longest dehydration duration (1380 min) compared to other drying methods. In addition, drying time decreased with increasing temperature. For the three indoor drying methods, the contents of total lipid and fatty acids of dried Artemia were not significantly different from the control in most cases. On the contrary, sun drying resulted in a high loss of these substances compared to the original material. Moreover, at the same drying temperature, the longer drying time caused a higher loss of nutrients in the dried products as shown by the values in the MWHA sample which was slightly higher than in other two drying methods. Nonetheless, between the three indoor drying methods significant differences were not observed (P>0.05). In general, the intermittent MWHA drying is a promising technique, which could produce high quality dried products in short drying times. However, it might not be suitable for large-scale application because of high capital investment and operating costs. Therefore, sun drying method should be improved to optimize the use of renewable energy sources through application of solar dryer.