Marine food products, importance

Phosphorus is not only one of the essential components for the growth and breeding of phytoplankton, but also the fundamental element for marine primary productivity and the food chain. Sediment is one of the important sources of phosphorus in seawater moreover, it is a buffer for the phosphorus in overlying water. Therefore, it is of great significance for the dynamic cycle, the transformation at the sediment-seawater interface, and the subsequent digenesis to study phosphorus and its forms. 

Seaweed could be potentially used in the production of low fat foods due to their high level of important PUFAs. Fimctional food products enriched with (d-3 LCPUFAs are widely spread nowadays. The utilization of marine microalgae to produce high value lipids is suggested as the alternative sources of PUFAs. The utilization of algal enzymes in order to produce EPA and DHA from modified crops seems to be also the perspective interest. 

Aquatic and Marine Food. Fisheries scientists, as experts in the health of individual fish species and overall fishery populations, help industry provide high-quality seafood products for the consumer—an important activity, considering that seafoods are one of the world s primary sources of high-quality protein. Fisheries scientists are involved in product development, physicochemical principles, and process... 

The phytoplankton are the basis of all marine food chains. Then-primary productivity is constrained mainly by nutrient availability and is thus not uniform throughout the oceans. Moreover, the importance of the grazing pathway of energy transfer varies spatially along with detrital energy transfer (see Section 3.7) estimates of the latter vary from c. less than 10 percent to c. 90 percent. 

Fatty acids with odd numbers of carbon atoms are rare in mammals, but fairly common in plants and marine organisms. Humans and animals whose diets include these food sources metabolize odd-carbon fatty acids via the /3-oxida-tion pathway. The final product of /3-oxidation in this case is the 3-carbon pro-pionyl-CoA instead of acetyl-CoA. Three specialized enzymes then carry out the reactions that convert propionyl-CoA to succinyl-CoA, a TCA cycle intermediate. (Because propionyl-CoA is a degradation product of methionine, valine, and isoleucine, this sequence of reactions is also important in amino acid catabolism, as we shall see in Chapter 26.) The pathway involves an initial carboxylation at the a-carbon of propionyl-CoA to produce D-methylmalonyl-CoA (Figure 24.19). The reaction is catalyzed by a biotin-dependent enzyme, propionyl-CoA carboxylase. The mechanism involves ATP-driven carboxylation of biotin at Nj, followed by nucleophilic attack by the a-carbanion of propi-onyl-CoA in a stereo-specific manner. 

The individual characteristics and uses of the basic grades of the austenitic irons are given in Table 3.55. The major uses for these materials occur in the handling of fluids in the chemical and petroleum industries and also in the power industry and in many marine applications. The austenitic irons are also used in the food, soap and plastics industries where low corrosion rates are essential in order to avoid contamination of the product. Ni-Resist grades Type 2, 3 or 4 are generally used for such applications but the highly alloyed Type 4 Ni-Resist is preferred where low product contamination is of prime importance. 

An interesting and important example of an animal poison is paralytic shellfish poison (PSP). This chemical, which is also known as saxitoxin and by several other names as well, is found in certain shellfish. But it is not produced by shellfish it is rather a metabolic product of certain marine microorganisms (Protista). These microorganisms are ingested by the shellfish as food, and their poison can remain behind in the shellfish s tissue. Paralytic shellfish poison is not a protein, but a highly complex organic chemical of most unusual molecular structure. 

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