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The changes in the contents of dietary fibers, minerals, and free amino acids, and the fatty acid compositions of dried “nori” Porphyra yezoensis were examined during processing such as by cutting, mincing, mixing, and softening. The amount of soluble dietary fiber in nori cultivated at Chiba Prefecture was larger than that in Hyogo Prefacture; however, insoluble dietary fiber was reversed in each manufacturing process. Sodium and calcium contents of nori cultivated in Hyogo were larger than those in Chiba. Free amino acid contents such as taurine, alanine, and glutamic acid were higher in Chiba than in Hyogo during processing. Fat contents and the rate of icosapentaenoic acid in total lipid in the nori from Chiba were high, when compared with the counterpart in the process. There were no significant changes in any of the components during processing, when the results were expressed as g or mg per 100g of dry matter in each process. Therefore, we concluded that the specified components of nori were not lost to any significant degree in laver fronds during the processing of dried nori.

Hijiki Hizikia fusiformis, brown alga, was steamed for 6h, and kombu Laminaria ocho-tensis, brown alga, and nori Porphyra spp., red alga, were boiled in a seasoned solution for 2h by imitating the manufacturing method of boiled and dried hijiki, and tsukudani (seasoned and cooked seafood) of kombu and nori, and changes in dietary fiber in these seaweeds were studied. The water soluble dietary fiber of all seaweeds increased steadily during heat processing. However, the molecular weight of the main components in the soluble dietary fiber decreased during heating, and especially in the case of nori it diminished markedly to 15% of the unheated sample after 1h. There were some differences in the changes of insoluble dietary fiber content and, as to kombu, the insoluble type was reduced to 40% of the unheated sample by boiling for 1h. Amounts of carbohydrates dissolved from hijiki increased gradually during steaming, and the molecular weights of the main components in this fraction were comparable to those of the soluble dietary fiber in the hijiki.

Changes in dissolved carbohydrates from Gagome Kjemaniella crassifolia by gamma-irradia-tion and boiling were investigated. When pulverized Gagome was irradiated in the dry state, solubilized carbohydrate levels did not change at dose levels up to 50 kGy; however, the molecular weights of main components in the soluble matter decreased. The amount of dis-solved carbohydrates increased with dosage increments of gamma rays when irradiated in water, and their molecular weights decreased markedly. When Gagome was irradiated with a dose of 10 kGy in the dry state, and then boiled in water, the amounts of carbohydrates dissolved were markedly high at 80°C during 10-h boiling in comparison with those of the non-irradiated control. On the other hand, at 100°C no difference was observed after 4-h boiling. There was no significant difference in the quantity of dissolved carbohydrates or their molecular weights between irradiated and non-irradiated samples heated at 120°C for up to 12 h. From these results dietary fibers in Gagome were found to be extracted and degradated by irradiation.

Dietary fiber and minerals were analyzed in dried nori Porphyra yezoensis which was cultivated in eight main prefectures, i.e. Miyagi, Chiba, Aichi, Mie, Hyogo, Kagawa, Saga, and Kumamoto, and classified by price at auction. Insoluble dietary fiber was distributed within the range of 14.6 ?? 38.9g per 100g dry matter, and soluble dietary fiber within the range of 3.1 ?? 32.4g. Therefore, the total dietary fiber ranged from 19.6 to 59.8g. Low price nori as well as the sample harvested in March tended to contain high amounts of total dietary fiber. There were considerable variations in the contents of potassium (1, 610 ?? 4, 100mg/100g dry matter), sodium (510 ?? 2, 790mg), magnesium (53 ?? 249mg), calcium (46 ?? 331mg), iron (2.1 ?? 11.5mg), zinc (0.9 ?? 6.7mg), manganese (0 ?? 4.1mg), and copper (0.1 ?? 0.8mg). Mineral levels in nori seemed not to be correlated with the mineral concentration in sea water. No adequate correlation between these contents and prices was estimated from the results of the calculations.

Digestibility of the edible brown alga kombu was studied by feeding rats for 28 days. Food intake of both rats fed with basal and kombu diets was statistically similar. Body weights of kombu groups were significantly lighter, but their fecal weights were heavier, when compared with their counterparts with diets excluding kombu. There were no major differences in the weights of liver, pancreas, and kidney, but cecum, small intestine, and large intestine of rats fed with kombu were significantly heavier than those without kombu. With the kombu diet, in the early feeding period protein digestibility was signi-ficantly lower than in the control, but the digestibility of kombu groups recovered to the level of the control in the late feeding period. Fat digestibility in the kombu diet was significantly higher than that in the basal diet. Digestibility of insoluble and total dietary fibers in the kombu diet tended to increase in the feeding period. Alginate digestibility significantly increased, and the molecular weight of alginate was down by 60%. Since the molar ratio of mannuronic and guluronic acids in alginate decreased significantly in the feeding period, mannuronic acid may be more decomposable in comparison with guluronic acid in rats.

Free amino acids and fatty acid composition were determined in dried nori Porphyra yezoensis which was cultivated in eight prefectures and classified by price. Taurine, alanine, glutamic acid, and aspartic acid were detected in quantities amounting to 627 ?? 1, 637, 308 ?? 1, 602, 322 ?? 1, 844, and 66 ?? 282mg per 100g dry matter, respectively, and these four amino acids occupied more than 86% of the total free amino acids. Glutamic acid and alanine are known to be important free amino acids for the taste of nori, but according to statistics these contents had no correlation with auction prices. Fat content ranged from 1.84 to 5.22g/100g, and C20:5ns, icosapentaenoic acid (13.3 ?? 57.7%), and C16:0, palmitic acid (15.5 ?? 45.3%) were the main fatty acids in total lipid. There was no mutual relation between contents and compositions of dietary fibers, minerals, free amino acids and fat, or fatty acids.

The stock of brown alga, kombu, is used for Japanese dishes. Makombu Laminaria japonica cut into 1×1cm squares was irradiated at dose levels of 1, 10, and 100kGy under moisture contents of 10 or 40%, and then boiled up to 30min. Nitrogen, glutamic acid, and sugars in the kombu extracts were determined. When kombu was irradiated with a dose of 10 and 100kGy at 10% moisture, the amounts of extractive nitrogen boiled for 2 and 5min were about 1.4 times as many as those of non-irradiated control. Glutamic acid, one of the main constituents of delicious taste in kombu, was also highly extracted during 2 and 5min boiling in comparison with that of non-irradiated kombu. However, there were no significant differences in the amounts of either extractive nitrogen or glutamic acid after 30min boiling in any of samples. Sugars which deteriorated the quality of the kombu stock due to viscosity were dissolved in high amounts at a dose level of 100kGy. The amount of solubilized sugars from irradiated samples of 40% moisture was higher than that of 10% moisture, but no significant change was observed in other extracted substances during heating. From these results, the irradiation dose level of 10kGy was appropriate to obtain good kombu stock as a result of increased extractability.

Lipoxygenase-like activity was found in the crude extracts from the skin and gill of wild and cultured ayu. After incubation of arachidonic acid with the crude extract from the wild and cultured ayu skins, the major oxygenated product was estimated to be 12-hydroxyeicosa-tetraenoic acid under high-performance liquid chromatography using a Waters μ bondapak fatty acid column. On the other hand, eicosapentaenoic acid yielded 12-hydroxyeicosapentaenoic acid. This enzyme activity of wild and cultured ayu was inhibited strongly in the presence of the following reagents: BHA, esculetin, p-chloromercuribenzoate, SnCl2, CuCl2. The C9 carbonyl compounds and alcohols specifically formed from the oxidation of poly-unsaturated fatty acids in the crude extract of wild ayu skin. In GC-MS chromatogram, a peak height of (E, Z)-2, 6-nonadienal formed from the wild ayu skin was higher than that of the cultured ayu skin, while that of 3, 6-nonadien-l-ol from the wild ayu skin was lower than that from the cultured fish skin.

The volatile compounds collected on a porous polymer Tenax TA from wild and cultured ayu fish were evaluated by GC-sniffing and identified by GC-MS. GC-pattern and odor quality of wild ayu were similar to that of cultured ayu. The main compounds responsible for a cucumber-like and/or watermelon-like aroma were identified as (E, Z)-2, 6-nonadienal, (E)-2-nonenal, and 3, 6-nonadien-1-ol; (E, Z)-2, 6-nonadienal play a significant role in the characteristic aroma of ayu. However, by the same analytical experiment, it was shown that carbon-9 carbonyls and alcohol were not detectable in river algae eaten by wild ayu and in artificial diets for ayu culture.

Enzyme activity that involves generation of volatile compounds in selected tissues of ayu were studied. Lipoxygenase-like activity was found in crude enzyme from skin and gill tissues of ayu, but was not detected in the muscle tissue. The skin enzyme was found to be unstable; half inactivation occurred after 4 hours during storage at 0°C. Optimum pH and temperature were observed 7.4 and 25°C, respectively. Volatile compounds generated by the skin enzyme was dependent on the substrate of polyunsaturated fatty acid (PUFA). Five compounds including 1-octen-3-ol and (E)-2-nonenal were formed from arachidonic acid, and four compounds that include (E, Z)-2, 6-nonadienal and 3, 6-nonadien-1-ol were generated from eicosapentaenoic acid or docosahexaenoic acid. It suggests that those C9 carbonyls and alcohol which contribute to the ayu aroma may have been generated from the lipoxygenase-initiated oxidation of PUFA in the ayu skin tissue.

Volatile compounds collected into Tenax TA from fresh smelt Osmerus eperlanus mordax were analyzed by GC-sniffiing and identified by GC-MS. The strong cucumber-like aroma of smelt was characterized by the following C9 carbonyls and alcohols: (E, Z)-2, 6-nonadienal, (E)-2-nonenal, (E, Z)-2, 6-nonadienol, 3, 6-nonadien-l-ol, (E)-2-nonenol, and (Z)-6-nonenol. Among these compounds, (E, Z)-2, 6-nonadienal was found to make a most important contribution to the aroma of smelt. On the other hand, the activity of a lipoxygenase-like enzyme was found in the skin and gill of smelt. The crude skin enzyme exhibited nearly the same activity towards such sub-strates as arachidonic, eicosapentaenoic, and docosahexaenoic acids, but showed a negligible response to linoleic and linolenic acids. The C9 carbonyls contributing to the smelt aroma were found to be specifically generated from the oxidation of polyunsaturated fatty acids by the smelt skin enzyme system.

White and dark meats of bigeye tuna were packed in retortable pouches and thermally processed at 120, 110, and 100°C so far as to reach the equal lethality of F0 4, and the changes in extractive components of both meats were studied. As compared with the short time of heating at high temperature; the long time of heating at low temperature produced more intense browning of the meat extract, decrease in trimethylamine oxide, creatine, and total sugar, and increase in trimethylamine, creatinine, gelatin, and non-protein nitrogen. The decomposition of histidine and anserine, and the formation of gelatin in the dark meat were much greater than those in the white meat.

The decomposition of carnosine, anserine, and balenine during storage of the big-eye tuna and the sei whale meats was studied with a view to ascertain the formation of methyl derivatives of histamine and β-alanyl-histamine. A chromatographic deteiination of these amines on a 15cm column of a cation exchange resin (JEOL, LCR-2) was achieved using a borate buffer of pH 10.2 having sodium concentration of 0.32N, at 52°C. When the big-eye tuna meats with and without addition of chopped sardine skin were stored at 5°C for 12 days or 20°C for 5 days, and when the sei whale meats with and without addition of mackerel slime at 25°C or 37°C for 3 days, the meats turned putrid in the late stages of the storage periods. The amounts of anserine in the big-eye tuna, and carnosine and balenine in the sei whale did not decrease. Although a lot of histidine was decarboxylated into hislamine in the big-eye tuna meat at 20°C, the methyl derivatives of histamine and β-alanyl-histamine were not detected.

Seventeen strains of bacteria isolated from the putrefied meats of the sei whale and mackerel were incubated in the media containing balenine, and it was found that they are able to hydrolyze balenine in a greater or lesser degree. Among 68 strains of histamine-forming bacteria isolated from the sardine and mackerel, on the other hand, only 2 strains showed the hydrolyzing activities on carnosine or anserine when incubated in media having these imidazole dipeptides. β-Alanyl-histamine and its methyl derivatives which correspond to the decarboxylation products of carnosine and its methyl derivatives were not detected throughout the experiments.

Specimens of bigeye tuna and the Pacific halibut meats packed in retortable pouches were heated at 115°C up to F0 values of 8, 12, and 21, and the changes in extractive components were studied. The decrease of the total sugar content and increase in pH value, Hunter value, degree of browning of extract, and the non-protein nitrogen content were observed during thermal pro-cessing. Trimethylamine oxide and creatine changed into trimethylamine and creatinine, re-spectively, almost equivalently, Little changes were observed in the amounts of free amino acid and its related compounds, but only histidine decreased significantly.

In this paper, we discuss wind-induced surface drift inferred from drift-card returns and its implications on the variation of the oceanic conditions in the eastern Seto Inland Sea: the Sea of Harima and Osaka Bay. The wind stress factor estimated for the average drift speed of the cards was about 0.02, which suggests the wind effect is the most dominant influ nce on the movement of the surface water in this sea. In fact, the distribution of low salinity water on the surface of Osaka Bay showed quite different patterns according to the prevailing winds. This may be due to the effect of the wind-induced current coupled with a density current which is found throughout the year. It is also noticeable that prevailing W to NW winds which blow towards the southern coast of Osaka Bay will reduce the advective speed and dispersion of low salinity water, which may result in comparatively small water-exchange in winter. On the other hand, the northward drift of the surface water which is induced by a strong southerly wind in summer possibly cause an upwelling of the bottom water on the southern coast of the Sea of Harima.

In order to elucidate the origin and characteristics of the odor of fresh ayu (sweet smelt), the olfactory evaluation and the identification of volatile components of wild ayu, cultured ayu, and sessile algae as a natural diet for wild ayu were carried out. The characteristic odor of wild ayu was more in the viscera and skin, and resembled closely to that of the sessile algae. The main hydrocarbons, alcohols, and aldehydes were identified by GC and/or GC-MS, and it was indicated that 2-trans-6-cis-nonadienal and cis-3-hexenol have played an important role in the occurrence of the odor in the wild ayu. On the other hand, the cultured ayu differed in the pattern of the components and showed the existence of a lot of pristane which seemed to be caused by the lipid in the artificial diet.

The distribution of nitrogenous compounds in the hot water extracts of snapping turtles cultured with six different diets was investigated. Although the amounts of nitrogenous compounds fluctuated among the specimens examined, carnosine, taurine, glutamic acid, histidine, inosine monophosphate, adenosine monophosphate, creatine, and creatinine were found to be relatively in high concentrations. The main component was gelatin, where nitrogen accounted for 72-80% of the total nitrogen in the hot water extracts. The changes in level of free amino acids and related compounds in the hot water extracts of the animals obtained from a commercial source were also investigated during heating. Carnosine, histidine, and taurine, all of which were present initially in large quantities, decreased rapidly and their amounts were approximately halved after 48h of heating. The degree of browning of the hot water extracts increased rapidly after 12h, possibly relating to the decrease in levels of such nitrogenous compounds. Gelatin contents increased rapidly and reached a maximum level after 24h.

The changes in content and molecular weight of gelatin in hot water extracts from snapping turtles during heating were investigated. The amounts of gelatin and total nitrogen increased rapidly and reached a maximal value after 24h of heating. The breakdown of gelatin molecules occurred during heating; the average molecular weights estimated by a gel filtration and an SDS-polyacrylamide gel elect-ophoresis were approximately 50, 000 and 35, 000 after 8h, 28, 000 after 12h, 8, 000 after 24h, and 4, 000 after 48h. It was suggested that the degradation products of gelatin play an important role on the taste of the soup.

A field experiment with drifting hoop nets was carried out in the coastal water of the Kuroshio during 6-12 August 1977 in order to collect the small fish associated with drift algae. Two types of drifting hoop nets composed of 5 large (0.83m3) and small (0.22m3) hoop nets were released about 50 miles off Shikoku on 6 August and tracked; each type was retrieved twice during the tracking to catch the fish in the nets. The juvenile and young fish of 9 species (7 families) were collected including Arothran firmamentum (467 ind.), Abudefduf vaigiensis (71 ind.), Thamnaconus modestus (70 ind.) and Decapterus maruadsi (8 ind.). The greater part of the fish were collected with 7mm mesh large nets. T. modestus and D. maruadsi were mostly collected at a depth of about 13m in contrast to A. vaigiensis and A. firmamentum which were collected at the surface. Body lengths (ranging 80-108mm in BL) of T. modestus were somewhat larger than previously reported. The appearance of young A. firmamentum suggests that they possibly migrated in and around the Kuroshio Current off Shikoku during the period of this experiment.

To establish a simple polarographic method for determination of homarine occurring characteristically in marine invertebrates, extraction methods and supporting electrolytes were surveyed using the squid mantle muscle and liver.Homarine in the tissues was easily extractable with 5-20 volumes of boiling water. The use of 1N H2SO4 as a supporting electrolyte was proposed, as it gave a well-defined first wave of homarine on polarography.The amounts of homarine in the squid mantle muscle and liver were determined by the modified method, and a higher value was found in the liver than in the mantle muscle. The recovery of added homarine was satisfactory, ranging from 99 to 101%.

The utility of the structural model as a tool for the assessment of environmental impact on coastal fisheries is described, together with its principles and procedures. This method uses existing information for structuring comprehensive ecological systems of fishing grounds and evaluating their functional change both directly and indirectly due to various impacts. A simple empirical formulation scheme is proposed as a means of quantifying the environmental impact. A set of variables, each of which indicates the rate deviation from the present state of each environmental factor, is used for the formulation. Each variable is normalized over the range (0-1) where we define the upper boundary for the present state and the lower boundary for the largest impacted state. Thus it also becomes possible to use simple multiplication to calculate the effects of multiple factors on a single factor. By inputting an initial value to the formulated structural model, one can estimate possible impacts on fisheries, for example, in terms of relative catch loss. Although this method has several limitations when handling feedback processes, etc., it seems to make conventional methods more concrete and quantitative.

A comparison of the difference between buffering capacrities of white and dark muscles of yellowfin tuna was made using β-pH curves, and the contribution of free histidine and its related dipeptides was investigated by means of omission test of the whole synthetic extract which was prepared by blending reagent grade chemicals on the basis of analytical values of the muscle ex-tract. The homogenate and picric acid extract of the white muscle showed higher buffering capac-ity than in the dark muscle, and the curve of the whole synthetic extract of the white muscle re-sembled that of a picric acid extract. When histidine and anserine, the most prominent nitrogenous compounds in the white muscle, were omitted, the buffering capacity was almost lost, and there-fore, these constituents were found to play the most important role in the buffering of the white muscle. In the dark muscle, these constituents, naturally, did not participate in the main buffering of the muscle, since it contained relatively low amounts of histidine and anserine.

In this paper, we consider the effects of wind variations on the surface drift of red sea bream larvae azound Shijiki bay, a well-known nursery area of the red sea bream off the northwestern coast of Kyushu, on the basis of the results of the drift-card experiment carried out in a spawning ground adjacent to the bay during March-July in 1982. It is suggested that a large amount of larvae would be transported from this local spawning ground to Shijiki Bay, especially under windless conditions. However, prevailing southerly winds during the spawning period will enable the larvae originating from more southern major spawning grounds to reach Shijiki Bay within several days after spawning, which may contribute to the rapid increase of the larval abundance in the bay. Conversely, under prevailing northerly winds, the transport of eggs and larvae from both local and major spawning grounds cannot be expected.

For the studies of protein contained in muscle of an aquatic animal on the basis of polarographic wave, it is necessary to grasp a protein wave typical of meat extractives of the aquatic animal. Here, the authors studied the method to determine a polarographic protein wave typical of meat extractives of aquatic animals. We also studied into the origin of the protein wave. The results are as follows: 1) In order to obtained the typical wave for meat extractives, it is necessary to change the amount of meat extractives relative to the ammoniacal cobaltic solution according to the extraction ratio of meat (Table 1). 2) It is experimentally ascertained that the polarographic waves treated here originate purely in protein and have no relation to non-proteinous extractive components of meat.

Many of the papers have been published on the subject of polarographic studies of proteins, but the polarographic characteristics of proteins contained in fish muscle are not known so far. So. in the present paper, the authors tried the application of polarographic protein wave to the studies of proteins contained in fish muscle, blood and internal organs. The following subjects are preliminary experimented and obtained hopeful results: 1) Difference of polarographic protein wave in the species of aquatic animal. 2) Difference of polarographic protein wave between common muscle and dark-colored muscle. 3) Determination of the freshness. 4) Denaturation of protein during the r-ray irradiation.