Development of a new method for determination of total haem protein in fish muscle. (15th April 2015)

• Record Type: Journal Article
• Authors: Chaijan, Manat; Undeland, Ingrid
• Is Part Of: Food chemistry. Volume 173(2015)
• Page Start: 1133
• Page End: 1141
• Publication Date: 2015-04-15
• Subjects: Quantification -- Method -- Haem proteins -- Haemoglobin -- Myoglobin -- Fish muscle -- Oxidation -- Hemichrome -- Sodium dodecyl sulphate; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2014.11.010
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: A new method for total haem protein determination in fish muscle was developed. SDS and heat dissolved the fish muscle and converted haem proteins to hemichrome. Hemichrome had a maximum absorbance at 535 nm. A new method was suited for fresh/frozen fish with ⩽30% lipid, <5% NaCl and pH 5.5–7. Abstract: Using classic haem protein quantification methods, the extraction step in buffer or acid acetone often becomes limiting if muscle is oxidised and/or stored; haem-proteins then tend to bind to muscle components like myofibrils and/or biomembranes. The objective of this study was to develop a new haem protein determination method for fish muscle overcoming such extractability problems. The principle was to homogenise and heat samples in an SDS-containing phosphate buffer to dissolve major muscle components and convert ferrous/ferric haem proteins to hemichromes with a unique absorption peak at 535 nm. Hb-recovery tests with the new and classic methods showed that the new method and Hornsey's method performed significantly better on fresh Hb-enriched cod mince than Brown's and Drabkin's methods; recovery was ⩾98%. However, in highly oxidised samples and in cod protein isolates made with acid pH-shift processing, the new method performed better than Hornsey's method (63% and 87% vs. 50% and 68% recovery). Further, the new method performed well in fish muscle with ⩽30% lipid, <5% NaCl and pH 5.5–7.0; it was also unaffected by freezing/frozen storage.