Shellfish Diet

Shellfish diet, USA Cmstaceans, edible tissues Tolerable daily intake Maximum allowable Adverse effects... 

The basic constituent of seashells is calcium carbonate, an insoluble compound formed from calcium ions secreted from the cells of the shellfish and carbonate ions present in seawater. But calcium carbonate is a white solid. The colors of seashells often arise from impurities and metabolic waste products captured in the solid shell as it is formed. Coloration is dictated by both diet and water habitat. For example, some cowries that live and feed on soft corals take on the hue of the coral species. Yellow and red colors often arise from carotenoid pigments such as //-carotene. Light refraction often generates the iridescent mother-of-pearl hues. 

Chikaraishi Y (2006) Carbon and hydrogen isotopic composition of sterols in natural marine brown and red macroalgae and associated shellfish. Org Geochem 37 428 136 Cimino G, Crispino A, Dimarzo V, Gavagnin M, Ros JD (1990) Oxytoxins, bioactive molecules produced by the marine opisthobranch mollusk Oxynoe olivacea from a diet-derived precursor. Experientia 46 767-770... 

In July 1979, mortalities of menhaden (Brevoortia tyrannus) occurred along the southern coast of Maine during a . excavata bloom ( ). Paralytic shellfish toxins were measured in the guts of these fish, up to 185 Jig per 100 g of viscera. Since phytoplankton constitute a major part of the diet of menhaden ( ), the toxins were probably acquired directly from ingestion of the toxic dinoflagellates. 

Cadmium is a widely distributed metal used in manufacturing and is present in a number of consumer products. Dietary exposure to cadmium is possible from shellfish and plants grown on cadmium-contaminated soils. Absorption is increased when associated with low levels of iron or calcium in the diet. Some plants, such as tobacco, can concentrate cadmium from even low levels in the soil. The lung readily absorbs cadmium, thus cigarette smokers have elevated cadmium exposure. Cadmium is also used as a metal alloy, in paint, and in batteries (Ni-Cad, nickel-cadmium). Workplace exposure can occur in welding and battery manufacture. 

While all humans have IgE antibodies fhaf are involved in defense against parasitic infections, only humans who are predisposed to the development of allergies will produce IgE antibodies upon exposure fo certain protein allergens present in their environment including their diet. Only a few of the many proteins found in foods are capable of sfimulating the production of specific IgE antibodies in susceptible individuals (Taylor, 2002). With molluscan shellfish, only one, or perhaps a few, of the numerous proteins is known to provoke the production of IgE antibodies that specifically recognize one or more species of molluscan shellfish. 

The only proven therapy for molluscan shellfish allergy is strict dietary avoidance. Problems may arise with avoidance diets when clam is present due to mislabeling or to cross-contact during food processing (Taylor and Hefle, 2005 Taylor et ah, 1986,1999). The food industry typically develops allergen control programs to prevent the occurrence of undeclared allergenic residues in other foods (Taylor et ah, 2006). The industry often uses... 

Modeling Conclusions. This exercise indicates that Th and U span the interface between the case where inhalation appears to dominate in the contribution of actinides in bone, and the case where ingestion is the more important pathway. The reasons for these differences lie in two important transfers The soil/sedi-ment to organism transfer (as it affects dietary concentrations) and the assimilation from the vertebrate GI tract. While terrestrial-derived foodstuffs dominate our diet, other components of the diet (i.e., aquatic-derived foods) may also make a contribution to intakes. Exceptions to the inhalation case may therefore occur in special populations where certain aquatic foods are consumed in greater amounts, i.e., shellfish (16). 

Calcium is also found in the rigid structural components of living things, either as the calcium carbonate of the shells of shellfish or the calcium phosphate of bone. About a kilogram of calcium is present in an adult human body, mostly in the form of insoluble calcium phosphate, but also as Ca2T ions in other fluids inside our cells. The calcium in newly formed bone is in dynamic equilibrium with the calcium ions in the body fluids, so calcium must be part of our daily diet to maintain bone strength. 

Vegetables are the major sources of provitamin A carotenoids, followed by fruits. Milk products, egg yolk, shellfish, and Crustacea also contain active carotenoids, which are derived from the animal s diet. The carotenoid distribution in green leafy vegetables is generally constant, whereas fruits contain a greater variety of carotenoids in varying concentrations. In ripening fruits, the decrease in chlorophylls is frequently accompanied by an increase in the concentration of carotenoids and an increase in the ratio of carotenes to xanthophylls. 

The POP pesticides are hydrophobic compounds with low water solubility. However, natural waters play an important role in the transport and transformation of POPs, because similar to air, water is capable of transporting POPs through convection to areas far from application sites, such as (1-HCH found in the Arctic. More importantly, water is essential for humans and all living species and is closely related to their activities. Aquatic mammals are the species most seriously endangered by POP pollution of natural waters. Fish and shellfish are important pathways for POPs to enter the human body through diet. Aquatic ecosystems are very influential on human beings. Therefore, water pollution by pesticides has generated wide concern. 

Consumption of fish and shellfish was identified as the significant pathway for potential exposure of dolphins/porpoises to the POPs. Little information existed on the feeding habits of local dolphins/porpoises in Hong Kong waters. Based on the limited data available (Parsons, 1997 Jefferson, 2001), it was assumed that the dolphin diet consisted of 90% fish and 10% shellfish (mainly crustaceans and cephalopods), while the ratio of fish and shellfish in the porpoises diet was 50 50. Dietary exposure to individual POPs was calculated based on the concentration of POPs... 

Man is capable of living on an all plant or all animal diet, although omnivory is most common in human societies. Animal foods may be divided into two major categories as far as we are concerned vertebrate and invertebrate. Although invertebrate animals may play a significant part in the diet of many human societies, there has been little work on invertebrate taste chemistry (except for shellfish) from a human consumption standpoint. Shellfish taste is primarily due to inorganic ions, organic acids, amino acids and nucleotides (44). 

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