Effect of Freezing and Microwave Heating on Proteins from Codfish Fillets: Analysis by SDS Polyacrylamide Gel Electrophoresis

Abstract

Water soluble and insoluble proteins were extracted from codfish samples subjected to a rapid freeze (– 196°C), a slow freeze (– 15°C), 1 min microwave heating, and from fresh extracts. The water soluble protein content decreased significantly in both frozen samples and in the microwave heated samples when compared to fresh extracts. Analysis by SDS PAGE showed a significant loss in water soluble proteins after microwave treatment concomittant with the appearance of two high molecular weight species. No differences were apparent in the nonsoluble protein SDS PAGE profiles.

Separation of Cod (Gadus morhua) Fillet Proteins by Electrophoresis and HPLC after Various Frozen Storage Treatments

“…Seldom has sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) been applied to monitor the changes in isolated myofibrillar (Gill et al, 1979) and sarcoplasmic proteins (Awad et al, 1969;Yowell and Flurkey, 1986) of fish muscle subjected to various frozen storage conditions. These studies have indicated that SDS-PAGE is a time consuming but sensitive method of detecting molecular changes in frozen stored fish muscle tissue.…”

“…Electrophoresis often has been used as an aid in the species identification of fish and fish products (Tsuyuki et al, 1966;Mackie, 1969Mackie, , 1972Seki, 1976;Morel, 1977;Kokuryo and Seki, 1978;Makcie and Jones 1978;Mackie and Taylor, 1972;Hume and Mackie, 1980;Makcie, 1980). Seldom has sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) been applied to monitor the changes in isolated myofibrillar (Gill et al, 1979) and sarcoplasmic proteins (Awad et al, 1969;Yowell and Flurkey, 1986) of fish muscle subjected to various frozen storage conditions. These studies have indicated that SDS-PAGE is a time consuming but sensitive method of detecting molecular changes in frozen stored fish muscle tissue.…”

Recent Advances in Food Thawing Technologies

“…The myosin and actin changes in red hake muscle thawed at 4°C were evaluated using SDS-PAGE (Bigelow & Lee, 2007). Yowell and Flurkey (1986) studied SDS-PAGE profiles of nonsoluble proteins in codfish fillets thawed using a microwave. The proteomic analysis of fresh and freeze-thawed porcine longissimus thoracis muscle was studied by Kim et al (2015) using twodimensional gel electrophoresis and mass spectrometry.…”

Species Substitution of Restaurant Fish Entrees

“…Cooking, however, denatures proteins and decreases their solubility and causes significant changes of electrophoretic protein patterns in gel (Yowell and Flurkey 1986). Although urea has been used to increase the solubility of heat-denatured fish proteins (An et al 1989;Makie 1969Makie , 1980Mackie and Taylor 1972), the complications involved in the protein extraction of cooked samples hampers the application of IEF analysis on cooked fish for routine analysis.…”