Stability of omega-3 polyunsaturated fatty acids (PUFAs) and astaxanthin pigments in a aqueous suspension of krill oil/chitosan microcapsules was studied. Physically stable and homogeneous microcapsuies were obtained with chitosan of different molecular weight. PUFAs were stable during the first 15 days of the study retaining over 95% of the eicosapentaenoic acid and docosahexaenoic acid originally present in the oil. Astaxanthin and its ethers were not as stable as the PUFAs, however low.molecular weight chitosan showed a better protective effect than high molecular weight chitosan. The potential application of this micro-particulate system for PUFAs and liposoluble vitamin supplementation of processed human food and aquafeed is discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.