Abstract: This study aimed to scientifically evaluate the potential value of Euphausia superba as an emerging resource, and to provide useful data for the processing and utilization of small-sized shrimps into high value products. E. superba and Exopalaemon carinicauda were selected to analyze nutritional composition and umami taste characteristics. Moisture, crude protein, crude fat, ash, amino acid, and fatty acid composition were determined to analyze the nutritional characteristics. Free amino acids and flavor nucleotides were determined to calculate taste active value (TAV) and equivalent umami concentration (EUC), which indicated the umami taste. Results showed that there were significant differences in crude protein (13.25% vs. 16.41%) and fat (3.12% vs. 1.10%) contents between E. superba and E. carinicauda (P < 0.05). Their fatty acid compositions were significantly different as well. The content of unsaturated fatty acids in E. superba was relatively higher than in E. carinicauda. The total content of amino acids in E. superba protein hydrolysate was significantly lower than in E. carinicauda protein hydrolysate (P < 0.05), but the proportion of essential amino acids was higher in the former, meaning that the nutritional value of protein in E. superba was accordant with the FAO/WHO pattern. Inosine monophosphate (IMP) and glutamic acid (Glu) played a major role in contributing to the umami taste, and the EUC of E. superba and E. carinicauda was 11.01 and 12.98 g MSG/100 g respectively. Conclusively, E. superba and E. carinicauda have high nutritional values and desirable umami taste characteristics, indicating promising prospects for use as ordinary foods or condiments.

Key words: Euphausia superba, Exopalaemon carinicauda, nutrient, umami