Heating, fish

The types of CFAMs in heated fish oils include C20 and C22 acids of unknown structure, derived from eicosapentaenoate and docosahexaenoate, respectively, together with those from Cl8 fatty acids (Sebedio and De Rasilly, 1993). An adaptation of the described HPLC method (Fig. 5.17 Sebedio et al, 1994) included additional fractions between 18 0 and 20 0 and between 20 0 and 22 0 (using 19 0 and 21 0 as internal standards) encompassing C20 and C22 CFAMs, respectively. 

Two molecules of vitamin A are formed from one molecule of -carotene. Vitamin A crystallizes in pale yellow needles m.p. 64 C. It is optically inactive. It is unstable in solution when heated in air, but comparatively stable without aeration. Vitamin A is manufactured by extraction from fish-liver oils and by synthesis from / -ionone. The role of vitamin A in vision seems to be different from its systemic function. See also relincne and rhodopsin. 

Protein-Based Adhesives. Proteia-based adhesives are aormaHy used as stmctural adhesives they are all polyamino acids that are derived from blood, fish skin, caseia [9000-71 -9] soybeans, or animal hides, bones, and connective tissue (coUagen). Setting or cross-linking methods typically used are iasolubilization by means of hydrated lime and denaturation. Denaturation methods require energy which can come from heat, pressure, or radiation, as well as chemical denaturants such as carbon disulfide [75-15-0] or thiourea [62-56-6]. Complexiag salts such as those based upon cobalt, copper, or chromium have also been used. Formaldehyde and formaldehyde donors such as h exam ethyl en etetra am in e can be used to form cross-links. Removal of water from a proteia will also often denature the material. 

Vitamins. The preparation of heat-sensitive natural and synthetic vitamins (qv) involves solvent extraction. Natural vitamins A and D are extracted from fish Hver oils and vitamin E from vegetable oils (qv) Hquid propane [74-98-6] is the solvent. In the synthetic processes for vitamins A, B, C, and E, solvent extraction is generally used either in the separation steps for intermediates or in the final purification. 

Direct Uses of Geopressured Fluids. Many of the uses typical of hydrothermal energy, such as greenhouse, fish farm, and space heating, have been proposed for geopressured resources, but none has been commercially developed (34). Hydrothermal fluids are widely used in enhanced oil recovery, however, to increase production from depleted oil fields. 

Glycine derivatives and aUphatic sulfonates are examples of compounds that can function in this way. The use of these inhibitors in cooling systems is usually lirnited by their biodegradabiUty and their toxicity toward fish. In addition, they can form thick, oily surface films, that may severely retard heat transfer. 

Many geothermal reseiwoirs contain hot water at a temperature too low for electricity generation. However, the water can be used to heat buildings such as homes, greenhouses, and fish hatcheries. This heating can be either direct or through the use of heat pumps. 

Direct geothermal energy is used for space heating of homes, greenhouses, livestock barns, and fish-farm ponds. As well, it is employed as a heat source in some industrial processes, such as paper production in New Zealand and diying diatomite in Iceland. Since the industrial applications usually require high-... 

Flat pieces of product, such as fish fillets, would suffer a change in shape in a free air blast and are better on a flat moving belt. Here, some of the heat goes direct to the cold air and some by conduction to the belt, which is usually of stainless steel. This tunnel... 

Sediment, fish, vegetation (total lead) Digestion of sample with acid and heat dilution with water AAS 50 ng/g (sediment) 10 ng/g (fish and vege-tation) No data No data Chau et al. 1980... 

Grains, milk mussel, fish Bomb digestion of sample with acid and heat or digestion with acid and dry ashing dissolution in acid dilution with water GFAAS 20 pg/g (bomb) 5 pg/g (dry ash) No data 85-107 75-107 Ellen and Van Loon 1990... 

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