Journal of Food Biochemistry 29 (2005) 71–87. All Rights Reserved. © Copyright 2005, Blackwell Publishing 71 PHYSICOCHEMICAL PROPERTIES OF MUSCLE AND NATURAL ACTOMYOSIN EXTRACTED FROM FARMED ATLANTIC SALMON (SALMO SALAR) STORED AT 4C HAIHONG WANG 1 , ANDREA M. LICEAGA-GESUALDO and EUNICE C.Y. LI-CHAN 2 Food, Nutrition and Health Program Faculty of Agricultural Sciences The University of British Columbia Vancouver, BC, V6T 1Z4 Canada Received for Publication December 17, 2003 Accepted for Publication July 2, 2004 ABSTRACT Properties of farmed Atlantic salmon (Salmo salar) obtained commer- cially were studied as a function of storage at 4C for 9 days. While pH increased gradually during storage for both samples, significant differences between samples were noted in water-binding capacity (WBC) of muscle, as well as surface hydrophobicity (S o ) and sulfhydryl contents of extracted nat- ural actomyosin (NAM). Lower S o was observed for NAM extracted from muscle stored for 2 days, coinciding with high WBC of the muscle. In contrast, higher S o from 5 to 7 day-stored samples coincided with minimum extractabil- ity and high apparent viscosity of NAM. Reactive sulfhydryl groups were higher at the beginning and end of storage. Generally, WBC of fish muscle was dependent on pH and related to changes in S o of NAM, while apparent viscosity increased with S o and disulfide content. The results indicate variabil- ity in functional properties of the salmon samples during cold storage, which could be attributed to changes in physicochemical properties of NAM. INTRODUCTION Farmed salmon has become more popular over the last decade, par- ticularly because of the market advantages of year-round availability and Blackwell Science, LtdOxford, UKJFBCJournal of Food Biochemistry0145-8884Copyright 2005 by Food & Nutrition Press, Inc., Trumbull, Connecticut.20052917187Original Article PHYSICOCHEMICAL PROPERTIES OF COLD STOR ATLANTIC SALMONH. WANG, A.M. LICEAGA-GESUALDO and E.C.Y. LI-CHAN 1 Current address: Department of Applied Microbiology and Food Science, University of Saskatchewan, 51 Campus Drive, Saskatoon SK S7N 5A8, Canada 2 Corresponding author. TEL: 604-822-3959; FAX: 604-822-6182; EMAIL: ecyl@interchange.ubc.ca