Water in meat

Meat proteins include sarcoplasmic, myofibrillar, and connective tissue proteins. Among the sarcoplasmic proteins are heme pigments and enzymes, which influence the color, smell, and structure of meat. Myofibrillar proteins and collagen are able to retain and hold water in meat structure and to emulsify fat. Therefore they influence the rheological properties of meat products. 

Potassium sorbate may also be used in meat and poultry food products under USDA regulations (156,157). The USDA regulations allow its use only to retard mold growth in sausage, including beef jerky, when appHed from a 10% water solution to casings before or after stuffing. 

SFE of fruits and vegetables and meat products has been reported, but the sample preparation techniques necessary to obtain reproducible results are extremely time consuming. Solid absorbents such as Hydromatrix, Extrelut " anhydrous magnesium sulfate or absorbent polymers are required to control the level of water in the sample for the extraction of the nonpolar pesticides. Without the addition of Hydromatrix, nonpolar pesticides cannot penetrate the water barrier between the sample particles and the supercritical CO2. The sample is normally frozen and the addition of dry-ice may be required to reduce losses due to degradation and/or evaporation. Thorough reviews of the advantages and limitations of SFE in pesticide residues... 

Offer G and Knight P (1988), The structural basis of water-holding in meat , in Lawrie R, Developments in Meat Science, Elsevier, London, 63-243. 

On the basis of evidence presented herein, this author conservatively estimates that, in terms of total carbofuran in water, damage is possible to aquatic invertebrates at >2.5 pg/L and to teleosts at >15 pg/L. These levels could be attained during a heavy rainfall shortly after carbofuran treatment of adjacent fields. Among sensitive species of warm-blooded animals, dietary concentrations as low as 10 pg/kg ration have demonstrable effects, which were measurable only after extended periods postingestion. For comparison, this level is about 1/5 that allowed in meat by-products for... 

In water, the concentration of toxaphene considered safe for protection of freshwater life is conservatively estimated to lie between 0.008 and 0.013 pg/L for marine life, it is 0.07 pg/L. This is in sharp contrast to the current recommended drinking water criterion for human health protection of 5.0 to 8.8 pg/L. Similarly, residues in fish tissue in excess of 0.4 to 0.6 mg/kg wet weight may be hazardous to fish health and should be considered as presumptive evidence of significant environmental contamination, although fish may contain up to 5.0 mg/kg before they are considered hazardous to human consumers. Toxaphene criteria for human health protection — which range in various foods from 0.1 mg/kg for sunflower seeds to 7.0 mg/kg in meat, fats, and citrus fruits — also appear adequate to safeguard sensitive species of wildlife. 

Several qualitative and quantitative immunochemical methods for CAP analysis in biological matrices of animal origin have been described [101,102, 104,105] (see Table 3). Van de Water et al. [ 102] described an ELISA that detected CAP in swine muscle tissue with an IC50 value of 3 ng mL1. This immunoassay was improved and subsequently optimized incorporating the streptavidin-biotin amplification system. There are also several commercially available test kits (see Table 4). RIDASCREEN is a competitive enzyme immunoassay for the quantitative analysis of CAP residues in milk, eggs, and meat in a microtiter plate. The measurement is made photometrically, obtaining a LOD of 100 ng L 1 in meat and eggs and 150 ng L 1 in milk. The test has been also applied to the analysis of tetracyclines. 

The coconut is an unusual food for many reasons. It is technically a seed, produced by the coconut palm tree, and as such is one of the largest edible seeds produced by any plant. Its unusual contents also make it unique in the seed world—the interior consists of both meat and water. The meat is the white pith with which we are all familiar, as it is used extensively for cooking and flavorings the coconut water is a white liquid that is very sweet and thirst-quenching. 

In summary, the above studies on the relationship between meat structure, composition, and transverse relaxation are consistent with the ascription assignment of the T2i relaxation component to water located in the myofibrillar protein matrix. In addition, the studies confirm that transverse relaxation is an excellent tool for obtaining information about structural features in meat. 

In conclusion, compared with transverse relaxation, no impressive results regarding longitudinal relaxation measurements in meat science have been demonstrated at present, as it has mainly been shown that Ti expresses differences in water content. Taking into consideration the faster acquisition of transverse relaxation times compared with longitudinal relaxation, and the more hidden features in the longitudinal relaxation, it can be speculated if longitudinal relaxation will ever gain same attraction in meat science as transverse relaxation. 

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