Development of a sodium dodecyl sulfate-polyacrylamide gel electrophoresis reference method for the analysis and identification of fish species in raw and heat-processed samples: A collaborative study

Abstract

A collaborative study was carried out in seven European labs with the aim of achieving a sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) standard operation procedure to identify fish species in raw and cooked samples. Urea and SDS-containing solutions were evaluated as extractants. Several preelectrophoretic operations--such as treatment with RNase/DNase, ultrafiltration and desalting--and up to ten types of gels and three SDS-PAGE systems were considered. The SDS-containing solution allowed a higher protein extractability than urea. Unlike urea extraction, SDS extraction seemed not to be influenced so much by the state of the sample (raw, cooked at 60 degrees C, cooked at 85 degrees C). Desalting, ultrafiltration or treatment with RNase/DNase did not improve the discriminatory power of the protein patterns. Commercial homogeneous 15% ExcelGels, especially when they were silver stained, yielded good results and afforded higher reproducibility, thus allowing a better matching of results among the laboratories participating in this collaborative study. Under the optimized technical conditions described above, all the fish species tested, either raw and cooked, yielded reproducible and discriminant species-specific protein patterns.

Forensics: Food Authentication Using MtDNA

“…Enzyme-Linked Immunosorbent Assay (ELISA) has been successfully applied in identifying fish species [21,22]. Several electrophoretic techniques are also now available for species identification, including Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) [23] native or urea-Isoelectric Focusing Electrophoresis (IEF) [23][24][25] and Two-Dimensional Electrophoresis (2-DE) [26]. Protein electrophoretic techniques however, not reliable for resolving mixtures of meat species in highly processed meat products because the protein profiles of a single species produces a complex banding pattern, which often overlap the species-specific bands [10].…”

Effect of the antioxidant profile in the diet of farmed coho salmon (<i>Oncorhynchus kisutch</i>) on the nutritional value retention during frozen storage

“…Total carbohydrates were estimated by rounding up, with the results expressed as g 100 g -1 muscle. Sarcoplasmic protein extracts were prepared in a low-ionic strength extraction buffer and quantified according to Piñeiro et al (1999). Results were expressed as g 100 g -1 muscle.…”

Methods of gadoid fish species identification in food and their economic impact in the Czech Republic: a review

“…Species identification of raw or heat treated gadoid fish by urea-IEF and SDS-PAGE Pineiro et al, 1999;Rehbein et al, 1999) are presented in Tables 3 and 4. An isoelectric calibration kit containing fish muscle parvalbumins was prepared and tested for its suitability for IEF in the presence of 8M urea.…”