Cod muscle

Animal bone, ground whole carp, cod muscle, tuna, dogfish liver... 

Pauwels J, Kureurst U, Grobecker KH, Quevauviller P (1993) Microhomogeneity study of BCR candidate reference material CRM-422 - cod muscle. Fresenius J Anal Chem 345 478-481. Pauwels J, Lambeety A, Schimmel H 1998a) Homogeneity testing of reference materials. Accred Qual Assur 3 51-55. 

The sample is now ready for analysis using the procedures described above (see Basic-Protocol and Alternate Protocol). Figure D1.6.6 shows chromatograms of cod muscle lipids before and after hydrogenation. Note the single peaks for steryl esters and free fatty acids in panel C compared to the double peaks in panels A and B. 

The unfreezable water may have more than a theoretical meaning. Adding more water than the total of the unfreezable to biopolymers, small amounts of freezable water are observed but the freezing point is reduced (see Figs. 16 and 20 in 181 ). So in fish (cod) muscle water freezes at —10 °C 208. Feeney has found a special anti-... 

Dyer WJ, Hiltz DF, Ackman RG, et al. 1970. In vivo assimilation by cod muscle and liver tissue of elemental phosphorus from polluted sea water. Journal of the Fisheries Research Board of Canada 27 1131-1139. 

A simple alkaline extraction method, at elevated temperatures (90°C) in a sealed vessel was applied to the determination of I, employing TMAH and ICP-MS [31]. All the I present in the samples (milk powder, egg powder, cod muscle, pig kidney) was extracted completely by TMAH. The results were con-brmcd by decomposition of the samples. 

Example. Evaluation of the Bias of the Analysis of Hg with the Automatic Analyzer AMA254 The CRM-422 Cod Muscle (with a concentration of Hg of 0.559 + 0.016 pg g-1) has been analyzed 12 times. The results are presented in Table 6.2. Student s t can be calculated from the experimental data and the reference value and uncertainty of the CRM. The standard error associated with the reference value is derived from the uncertainty of the CRM 5ref = Urcf/2. The uncertainty of the CRM is the 95 percent confidence interval. 

Four different extraction procedures have been evaluated for a quantitative recovery of Se species during extraction from cod muscle. The highest Se recoveries were obtained in the presence of enzymes, whereas only 5 percent of total Se in cod was extracted when a soft extraction procedure (MeOHDHCl) was used [42]. The use of proteolytic enzymes allowed to extract more than 90 percent of Se present in the wheat Bour samples and more than 85 percent of Se from yeast samples [43]. 

Selenium Speciation in Edible Animal Tissues Reports on Se specia-tion analysis in edible animal tissues have been scarce. Speciation analysis of Se in cod muscle tissue was performed by separating the species using both RP- and SE-HPLC prior to ICP-MS detection. The main Se compound found in enzymatic hydrolysates was selenomethionine [42], This selenocompound was absent in MeOHDHCl extracts, indicating that Se was mainly incorporated into proteins. A number of unidentiFed Se species were also detected in cod muscle tissue, the separated Se compounds being quantised on-line by post-column isotope dilution [42], Soluble Se compounds extracted from muscles of chicken, turkey, duck, ostrich, lamb, cattle, and pig were separated by SEC with ICP-MS detection. Four peaks were observed, but distribution of Se among these peaks varied considerably in tissues from different animal species [86]. 

V. Diaz Huerta, M. L. Fernandez Sanchez, A. Sanz-Medel, Quantitative selenium speciation in cod muscle by isotope dilution ICP MS with a reaction cell comparison of different reported extraction procedures, J. Anal. Atom. Spectrom., 19 (2004), 644D648. 

On the other hand, King (69) and Anderson and coworkers (70,71), based on detailed analyses of ultracentrifugal patterns of extracts of frozen stored cod muscle and experiments on the effect of lipids on protein denaturation, have proposed that denaturation of F-actomyosin occurs by two parallel pathways which lead to insolubilization (Figure 2). As indicated by Connell (61), the occurrence of G-actomyosin at an intermediary stage needs experimental verification. Possibility of an alternate pathway involving lipids will be discussed later. 

Jarenback and Liljemark (75,76) found similar changes in cod actomyosin solution and cod muscle during frozen storage. The denatured myosin was not extracted with salt solution. 

Connell has proposed that insolubilization of actomyosin during frozen storage of cod muscle is attributable to the denaturation of myosin rather than actin (89). During 40 weeks storage at -14°C, extractability of actomyosin and myosin decreased in parallel, while that of actin appeared to remain constant. The decrease in extractability of myosin was biphasic, while that of actomyosin followed an exponential curve. 

Similar inconsistencies have been encountered in the determination of other elements such as selenium [125,133], arsenic [118,130], copper [119,123] and zinc [120,122]. On the other hand, methods for the determination of mercury are slightly more consistent, with many workers using a closed-vessel nitric acid digestion procedure. Good results have thus been obtained with pig kidney [124,141], mussel tissue [138], cod muscle [137], citrus leaves [136], pine needles [136], albacore tuna [131] and fish tissue [124], among others. 

Sodium chloride has long been used for food preservation. Salt alters both the aroma and the taste of food. Addition of sodium chloride to blended cod muscle accelerates the development of rancidity (Castell et al., 1965 Castell and Spears,... 

Actomyosin denatures also in situ under the influence of hypertonic salt solutions. When cod muscle is immersed in various concentrations of sodium chloride, there is a critical salt content in the fillet (8% to 10% NaCl) at which denaturation occurs together with a rapid loss of water and uptake of salt (Duerr and Dyer, 1952 Fougere, 1952). In herring, however, this critical salt concentration is much lower (3 % NaCl) (Nikkila and Linko, 1954b). The stability of the native configuration appears very variable, but we are unable to explain such differences. The need for a better knowledge of the protein itself is clearly stressed by these researches. Let us now consider the recent progress made in this direction. 

This protein was recently prepared from cod muscles and investigated by Connell (1954). Acetone-dried muscle fiber was extracted with water by the method of Feuer, et al. (1948) omitting the final treatment with Na2COa (Tsao and Bailey, 1953). The G-actin obtained polymerizes on addition of salts to a viscous solution of F-actin showing pronounced double refrac-... 

Another process of degradation in muscle which appeal s also more rapid in fish than in warm-blooded animals have been described by Tarr (1952, 1953, 1954) and by Tarr and Bissett (1954). An important liberation of ribose occurs post-mortem in fish from ribonucleic acid, ribotides, ribosides, ATP, and ribose-5-phosphate under the influence of riboside hydrolases. A partial purification of these enzymes isolated from lingcod and rock cod muscle has been carried out recently (Tarr, 1955). As ribose plays a predominant role in the browning of heat-processed fish products, more work will certainly be done in this direction in the near future. 

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