Chemical composition and antioxidative activity of Thai traditional fermented shrimp and krill products

Chemical composition and antioxidative activities of some Thai traditional fermented shrimp and krill products including Jaloo, Koong-Som and Kapi were studied. All products did not contain myosin heavy chain or actin, but contained a large amount of small peptides. Kapi had the highest protein content, whereas carbohydrate content varied with products. Water-soluble fraction from all products possessed DPPH and ABTS radical-scavenging activity, as well as ferric reducing antioxidant power (FRAP) in a concentration-dependent manner. At the same concentration tested, the water-soluble fraction from Kapi exhibited the highest antioxidative activity. Soluble fraction of all products showed high stability over a wide pH range (2–11) and was stable after heating at 40–100 °C for 15–60 min. Fractions from all products heated at 100 °C had increases in FRAP, suggesting the enhancement of antioxidant activity. Therefore, fermented shrimp and krill products could be used as a potential source of nutrients and natural antioxidants.