Meat and Fish

Meat is mainly muscular tissue of dead animal. It has a complex fibrillar structure containing several kinds of protein and other molecules, which are suspended in sarcoplasmic fluid and held together by tissue containing fat and blood vessels. 

Important constituents of muscle fibres are two proteins, actin and myosin, which are involved in muscle contraction (Chapter II.5). Although the composition of meat is very variable, a representative average composition is listed in Table 12.21. 

Meat is traditionally regarded as a good source of protein and B vitamins. Apart from the phospholipids lecithin, cephalin and sphingomyelin, which make a major contribution to the total lipid content, the remaining P compounds in meat are individually present in quantities of less than 0.1%. These compounds include creatine phosphate (CP), inosinic acid, B group vitamins. 

The tenderness and flavour of meat can be greatly influenced by the treatment of the animal immediately prior to, and after slaughter, and the conditions under whieh rigor mortis has occurred. The best meat quality seems to be assoeiated with a minimum rate of disappearance of ATP after the death of the animal, and maintenance of pH 5.0-5.5. 

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Sources of human exposure to formaldehyde are engine exhaust, tobacco smoke, natural gas, fossil fuels, waste incineration, and oil refineries (129). It is found as a natural component in fmits, vegetables, meats, and fish and is a normal body metaboHte (130,131). FaciUties that manufacture or consume formaldehyde must control workers exposure in accordance with the following workplace exposure limits in ppm action level, 0.5 TWA, 0.75 STEL, 2 (132). In other environments such as residences, offices, and schools, levels may reach 0.1 ppm HCHO due to use of particle board and urea—formaldehyde foam insulation in constmction. 

Eor fresh poultry, a potassium sorbate dip significantly reduces total viable bacteria and doubles the refrigerated shelf life of ice-packed broilers (133). In cooked, uncured, vacuum-packaged turkey and poultry stored at 4°C, 0.2—0.25 wt % potassium sorbate suppresses microbial growth for up to 10 days (134). Sorbic acid at 0.5% in a marinade mixture for chicken dmmmettes extends refrigerator shelf life (135). Country-cured hams sprayed with a 10 wt % potassium sorbate solution showed no mold growth for up to 30 days (136). A review of sorbate use in meat and fish products has been pubHshed (137). 

Meat and fish are very liable to bacterial putrefaction in this connection an interesting innovation is the increasing use of easily cleaned aluminium fish boxes. It is also possible that copper should be avoided in contact with herrings, which have a high fat content. 

Obana, H., Eurata, M., and Tanaka, Y., Analysis of 2-aUcylcyclobutanones with accelerated solvent extraction to detect irradiated meat and fish, J. Agric. Food Chem., 53, 6603, 2005. 

Meat and fish Sweden maximum values 1500 Bq (40,500 pCi) cesium-137/kg FW 14... 

Presently about 20 different mutagenic and/or carcinogenic heterocyclic amines (HAs) have been isolated from various heat-processed foods. One class of these HAs is formed by pyrolysis of proteins or some amino acids. These HAs are amino-carbolines (Figure 13.7), and have been identified in grilled, broiled, baked, and fried meat and fish products, in meat sauces and bouillons, as well as in pyrolyzed proteins, glutamate, lysine, phenylalanine, tryptophan, ornithine, and creatine. 

The second group of mutagenic and carcinogenic HAs comprises compounds that are formed at lower temperature and have been found in cooked meat and fish dishes, gravies, pan residues, broiled and fried beef, and... 

Meat and fish scraps Dog feces, used cat litter Disposable diapers Coal ashes... 

Earge amounts of citrus peel Dairy products Meat and fish Cat/dog feces Purchased flowers... 

Niacin is present in foods mainly as coenzyme NAD and NADP, which are hydrolyzed in the intestine, and it is adsorbed as nicotinamide or nicotinic acid. The free forms, nicotinamide and nicotinic acid, only allowed to be added in fortified foods [403], occur naturally in limited amounts. Instead, niacin occurs as nicotynil ester bonded to polysaccharides, peptides, and glycopeptides. In general, niacin is widespread in foodstuffs (cereals, seeds, meat, and fish). High concentrations are present in roasted coffee beans as a primarily product of the roasting process [417]. 

Di(2-ethylhexyl) phthalate is ubiquitous in the general environment as a result of its widespread use in poly(vinyl chloride) products. It is found in ambient air at levels usually below 100 ng/m. The highest levels of di(2-ethylhexyl) phthalate in foods are found in milk products, meat and fish and in other products with a high fat content, where concentrations up to 10 mg/kg have been reported. The leaching of di(2-ethyl-hexyl) phthalate Ifom flexible plastics used in medical devices, such as during dialysis and transfusion, can result in large direct exposures. 

Results of a national survey conducted by the Ministry of Health and Welfare on residual antibiotics in domestic meat and fish in Japan for the fiscal years 1990-1992 are presented in Table 13.25. Samples were collected at the urban... 

A second important difference between mitochondrial and peroxisomal fi oxidation in mammals is in the specificity for fatty acyl-CoAs the peroxisomal system is much more active on very-long-chain fatty acids such as hexacosanoic acid (26 0) and on branched-chain fatty acids such as phytanic acid and pristanic acid (see Fig. 17-17). These less-common fatty acids are obtained in the diet from dairy products, the fat of ruminant animals, meat, and fish. Their catabolism in the peroxisome involves several auxiliary enzymes unique to this organelle. The inability to oxidize these compounds is responsible for several serious human diseases. Individuals with Zellweger syndrome are unable to make peroxisomes and therefore lack all the metabolism unique to that organelle. In X-linked adrenoleukodystrophy (XALD), peroxisomes fail to... 

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