Comparative Nutritional Evaluation of Three Dried Krill Products Commercially Available in Sri Lanka

Abstract

In the recent past krill (Sinhala: kooni) has been widely considered for its nutritional value. However almost all the pastnutritional studies on krill have been based on temperate species. Literature related to biochemical composition of tropical species are few. In Sri Lanka no work has been reported on krill. Therefore in the present study, it was aimed to investigate the proximate composition, fatty acid profiles and mineral contents of three dried krill varieties commercially available in Sri Lanka. They included a sun-dried Sri Lankan krill product, a boiled and sundried krill variety imported from Indonesia and a freeze-dried variety imported from India. Based on the observable characteristics, these products most probably belong to the genera Stylocheironand/or Nematoscelis. Crude protein contributed upto54.6 – 71.6% of the dry matter. Crude fat content varied between 4.5 – 9.2% of the dry weight. The ash content was found to range from 22.0 – 40.7%on dry weight basis. GC/MS analysis of fatty acids revealed higher levels of polyunsaturated fatty acids (43.1 – 53.1%) for the three krill varieties. Predominating n-3 PUFAs fatty acids were eicosapenteinoic acid (EPA, C 20:5) and docosahexaenoic acid (DHA, C22:6). Linoleic (C18:2 n-6) and arachidonic (C20:4 n-6) acids were present as main n-6 PUFAs.Palmitic acid (C16:0) and palmitoleic acid (C16:1 n-7) were the main saturated and monounsaturated fatty acids, respectively. The calculated atherogenic and thrombogenic index values varied between 0.80 - 2.49 and 0.17 – 0.61 respectively. The mineral element analysis revealed values which ranged from 361.0 – 483.6 mg/100g, 522.3– 684.3mg/100g, 90.5 – 164.8 mg/100g and 503.8 – 776.0 mg/100g, for Na, Mg, K and Ca, respectively. Fe (3.5 – 6.5 mg/100g) and Zn (4.1 – 10.9 mg/100g) were detected as the major trace elements. Fluoride contents recorded in this study (23.2 – 63 ppm w/w) were much lower than those reported for krill in earlier studies. Overall, this study demonstrated that dried krill has promising nutritional value, due to its favourable biochemical composition, and deserve further exploitation to increase utilization.