Deterioration of Fresh-Water Whitefish Muscle During Frozen Storage at −10°C

SUMMARY— Organoleptic and chemical deterioration of freshwater whitefish muscle frozen at −10°C for periods up to 16 weeks was assessed. As frozen storage of muscle progressed, the toughness and rancidity of baked muscle increased. The solubility of the myofibrillar protein fraction, "actomyosin," dropped from about 72 to 22% over the 16 week storage period of whitefish muscle. No change in the solubility of sarcoplasmic protein in frozen stored muscle was observed. However, with polyacrylamide disc electrophoresis, two new sarcoplasmic protein bands were detected after 16 weeks of storage. With storage of frozen muscle, water-binding capacity diminished. Although the total lipid and cholesterol contents of muscle remained constant throughout frozen storage, the phospholipid content decreased as the free fatty acid content increased. Oxidative deterioration of lipid in frozen muscle was estimated.