Taste of fish

Phenol fumes are irritating to the eyes, nose, and skin. According to the National Institute for Occupational Safety and Health (NIOSH), exposure to phenol should be controUed so that no employees are exposed to phenol concentrations >20 mg/m, which is a time-weighted average concentration for up to a 10-h work day, 40-h work week. Phenol is very toxic to fish and has a nearly unique property of tainting the taste of fish if present in marine... 

In Japan, a wide variety of marine products, such as algae, molluscs, crustaceans, echinoderms, and fish have been consumed with relish from olden times. These food habits have stimulated many studies on the extractive components which may contribute to the taste of these products. Several comprehensive reviews on the subject are available (l-8 ) In order to avoid overlapping with them, special references are made in this review to those components whose roles in producing the taste of fish and shellfish have been examined organoleptically. 

The smell (and taste) of fish arises from amine compounds. Ionic compounds, such as ammonium salts, have lower vapor pressure than nonionic compounds. Suggest a reason why adding lemon juice (which is acidic) reduces the fishy smell. 

In 1824, Yohei Hanaya of Edo (now called Tokyo) eliminated the fermentation process, and began serving fresh slices of seafood on (35) bases of vinegared rice. The vinegar was probably used to mimic the taste of fermented sushi. In fact, the word sushi actually refers to any vinegared rice dish, and not to the fish, as many Americans believe (the... 

Maki zushi contains strips of fish or vegetables rolled in rice and wrapped in thin sheets of nori, or dried seaweed. Popular ingredients include smoked salmon, fresh crab, shrimp, octopus, raw clams, and sea urchin. Americans have invented many of their own maki zushi combi-(50) nations, including the California roll, which contains imitation crabmeat and avocado. They have also made innovations in the construction of maki zushi. Some American sushi bars switch the placement of nori and rice, while others don t use nori, and instead roll the maki zushi in fish roe. These colorful, crunchy eggs add to the visual and taste appeal of (55) the dish. 

In fish, both taste and olfactory stimuli are waterborne. However, taste involves the seventh, ninth or tenth cranial nerves, in contrast to the first cranial nerve for smell. Elasmobranchs have their taste buds in the mouth and pharynx, but in bony fish they occur around the gills, on barbels and pectoral fins, and also scattered over the rest of the body surface. They crowd particularly in the roof of the mouth, forming the palatal organ. The taste receptor cells are arranged as a bundle to form a taste bud. Like other vertebrates, fish have receptors for sweet, sour, salty, and bitter. For instance, goldfish reject quinine-treated food pellets (Jobling, 1995). Many fish species are particularly sensitive to acidic taste characteristics. The responses of fish to amino acids will be discussed in Chapter 12. 

Not surprisingly, much research in sharks, skates and rays has focused on the responses of sharks to human body odors. Human blood attracts sharks, while sweat does not, and urine was even slightly repellent (Tester, 1963). Practitioners use whale meat and mixtures of fish meal and fish oils as shark attrac-tants. In both carnivorous and herbivorous bony fish (Osteichthyes) smell deals with prey odors, social odors, and chemical stimuli in homing, and it is mediated by the first cranial nerve, the olfactory nerve. By contrast, taste serves in detection and selection of food and avoidance of toxic food, and it employs the facial, glossopharyngeal, vagal, and hypoglossal nerves. 

Covalent compounds generally have higher vapor pressure than ionic compounds. The fishy smell of fish arises from amines in the fish. Explain why squeezing lemon (which is acidic) onto fish reduces the fishy smell (and taste). 

The safety of drugs containing EPA and DHA has been reviewed the reported adverse effects were similar to those in control groups (3). Even 3-7 g/day for several months did not change liver enzyme activities, and there were no bleeding problems. Consumption of fish oils reduces the resistance of LDL to oxidative modification, and this is partly opposed by the addition of vitamin E (4). Belching or eructation with a fishy taste or smell, vomiting, flatulence, diarrhea, and constipation are relatively common. 

Meals prepared from grasshoppers contain as much as 760g/kg CP, but the amino acid profile is poorer than that of fishmeal (Ravindran and Blair, 1983). Moreover, the CP fraction is only 62% digestible. Feeding trials have shown that partial replacement of fish or soybean meals with grasshopper meal was feasible and that the taste of the meat was unaffected by its inclusion. 

Electrophysiological studies of the smell and taste systems of fish have likewise demonstrated chemoreceptor cells that are responsive, with varying degrees of specificity, to the amino acids known to elicit feeding behavior.73 75 In addition, a number of fish have receptor cells that respond to bile acids, amphipathic steroid compounds that are used as digestive detergents and that can be released into the environment in substantial quantities. Responses can exhibit both exquisite specificity for the structure of a bile acid, and extreme sensitivity, as best exemplified by the sea lamprey.76 77... 

The characteristic taste of monosodium glutamate and 5 -ribo-nucleotides is called "umami" in Japanese. It plays a predominant role in the flavor of foods, such as meats, poultry, fish and other sea foods, dairy products, or vegetables. The taste was first discovered by Ikeda (1908)(1), and has been studied by a large number of researchers from different points of view (refer to, e.g. 2 -9). ... 

Enormous efforts have been devoted to the analysis of the extractive components of fish muscles and much information has been accumulated. In recent years, the distribution of nitrogenous components in the muscle extracts of several species of fish has been elucidated almost completely (JJ, 10, 11, 12, 13). However, few studies have correlated these analytical data directly with taste. 

The role of histidine in making up the taste of scombroid fish seems to be a subject in need of further study. 

Lacasse, P., Kennelly, J.J., Delbecchi, L., Ahnadi, C.E. 2002. Addition of protected and unprotected fish oil to diets for dairy cows. I. Effects on the yield, composition and taste of milk. J. Dairy Res. 69, 511-520. 

Taste components of a number of sea food products have been examined for each sea food product has its individual characteristic taste. In studies on the free amino acids analysis (Table 9), it was shown that the major amino acid is His in red meat of fish, Gly and Pro in cuttlefish, Gly and Arg in prawns, and Tau and Arg in abalone ( ). The major amino acids in sea urchin are Gly, Ala and Leu (50). However, the components contributing to their individual characteristic tastes were not elucidated because the relationship between the taste components and the taste was not thoroughly correlated and Investigated in most of these studies. 

Although MSG is tasteless by itself, it is a flavor enhancer that can be used to improve the taste of meat, fish, fowl, vegetables, and soup. It is said to provide a unique flavor that is neither bitter, sour, sweet, or salty. Typically employed at concentrations of 0.2-0.9%, it is used extensively by the food industry in canned, frozen, and dried foods and Oriental food. It has also been used, with sugar, to improve the palatability of bitter drugs. 

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