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The chemical composition of muscles from Japanese eels cultured in hot-spring water was determined and compared with that of eels cultured in well water. The proximate composition did not differ significantly between the culture conditions, but the hepatosomatic indices of the hot-spring water eels were significantly higher than those of the well water eels. Amino acid levels were higher in the hot-spring water eels, and the carnosine content of the hot-spring eels was lower than that of the controls. Our results suggest that hot-spring water is a promising medium for eel culture, and its use may bring energy cost savings. [ABSTRACT FROM AUTHOR]

The effects of freshness level of raw materials, frozen temperature, and storage period on lipid oxidation and K-value of chub mackerel Scomber japonicus meat during frozen storage, were investigated. When the chub mackerel meat was stored at −20°C for 12 months, the peroxide values (PVs) of the low-freshness group (LG) were significantly higher than the medium-freshness group (MG) and the high-freshness group (HG), respectively. The K-value of LG was significantly higher than MG and HG. However, when storage was at −30°C, the PVs of HG were at the same level as that of MG but were slightly lower than LG. In contrast, the K-values of samples did not change at this storage temperature. These results indicate that the quality of chub mackerel before freezing was improved by human handling and that the quality was maintained at a high freshness even when they were stored at −20°C for 12 months. [ABSTRACT FROM AUTHOR]

Fermented foods are produced as a result of a preservation process that adds value to the final food product. This study aimed to evaluate the chemical components and radical scavenging activity of 11 fermented fish products from Thailand. Lipids extracts were used for the analysis of fatty acids, tocopherol, and radical scavenging activity, and water-soluble extracts were used for the analysis of free amino acids, inosine 5′-monophosphate (IMP), organic acids, and radical scavenging activity. The results showed that nam pla contained high levels of free amino acids and IMP; tai pla contained high levels of free amino acids and IMP; and kapi contained high levels of n – 3 fatty acids, α-tocopherol, free amino acids, and IMP. These three fermented foods also had higher radical scavenging activities than the other tested fermented foods. Furthermore, a strong correlation between chemical component and radical scavenging activity also occurs by principal component analysis. [ABSTRACT FROM AUTHOR]

In this study, the functional components of 19 microalgae and 6 bivalve species were investigated in the context of the application in bivalve feeding and human health food. Principal component analysis was performed to detect any association between the functional components and individual microalgal species or taxonomic group. The proportions of the functional components differed depending on the taxonomic group or species of microalga. The genera Cheatoceros, Thalassiosira, and Isochrysis contained high concentrations of fucosterol and fucoxanthin, which are present in large amounts in brown algae. Diatoms, haptophytes, and eustigmatophytes, which are used as feed for bivalves, were rich in fucosterol and eicosapentenoic acid (EPA); further, haptophytes were rich in docosahexaenoic acid (DHA). In addition, the microalgae associated with red tide, i.e., the raphidophytes, were found to be rich in fucoxanthin, β-sitosterol, and EPA, whereas dinoflagellates were rich in DHA. Seven bivalve species also contained high concentrations of fucosterol, EPA, and DHA, as did microalgae, which were used to feed by bivalves. These results are useful in selecting microalgae effectively as feed of the bivalves. [ABSTRACT FROM AUTHOR]

Histidine-containing dipeptides (HCDP) are widely distributed in the skeletal muscle of vertebrates, including marine and terrestrial organisms. In this study, we developed a simple, rapid, and accurate method for identifying HCDP by high performance liquid chromatography (HPLC) with isocratic elution. The method based on hydrophilic interaction chromatography (HILIC) using phosphorylcholine HILIC column (250 mm × 4.6 mm, 5 µm particles), 15 mmol/L ammonium acetate (pH 4.25):acetonitrile:methanol (3.5:5.85:0.65 by volume) as the mobile phase at 1.0 mL/min, and ultraviolet detection at 214 nm. As a result, HCDP, such as carnosine, balenine, and anserine, were separated in 20 min and the results were sufficiently reproducible and quantitative. Using this method, the limit of detection (LOD) was superior to previous methods. The LOD of carnosine, balenine, and anserine were 0.062, 0.085, and 0.100 µg/mL. The linearity range of carnosine, balenine, and anserine were 0.207-500, 0.283-500, and 0.334-500 µg/mL. The average recovery of that were 99.9, 91.7, and 100.1%. Our method was used to evaluate HCDP in marine and terrestrial organisms. Large pelagic migratory fish contained large amounts of anserine. Both land and aquatic mammals contained large amounts of carnosine compared with fish. Balenine was quantitated in minke whales, Japanese eels, pigs, and chickens. [ABSTRACT FROM AUTHOR]

The effects of a short chilled storage period before freezing, frozen storage temperature, and freezing rate on lipid oxidation of bluefin tuna (Thunnus thynnus) meat during frozen storage were investigated. After 12-months storage, all samples had increased in peroxide value though they were less at the lower temperatures (−45 and −60°C). Peroxide values in all samples stored at −20°C increased after 3 months storage, particularly those processed and stored 51 h after harvest. The lowest increase in peroxide value occurred in the samples frozen rapidly 3 h after harvest. Vitamin E levels decreased faster during frozen storage at −20°C. There were no apparent differences in levels of triacylglycerides nor in n-3 fatty acid levels between treatments, storage periods, and storage temperatures. After 12-months storage, headspace oxidative volatiles were highest in samples stored at −20°C and lowest in those stored at −60°C. Lipid oxidation in tuna meat stored at −45°C is similar to that at −60°C, and rapid freezing rather than slow freezing should be used. [ABSTRACT FROM PUBLISHER]

To determine the anti-allergic effects ofEcklonia kurome, the ethyl acetate fraction from anE. kurome(EEK) extract was compared to the ethyl acetate fraction from anEisenia arborea(EEA) extract and epigallocatechin gallate (EGCG) for inhibitory effects on inflammation in experimental animals, degranulation in inflammatory lymphocytes and enzymatic activities involved in allergic reactions. EEK was found to inhibit mouse ear oedema by inflammatory inducers (arachidonic acid, 12-O-tetradecanoylphorbol-13-acetate and oxazolone) in a dose-dependent manner, through both topical and oral administrations. EEK also inhibited degranulation in rat basophilic leukaemia cells and enzymatic activities (cyclooxygenase-2, soybean lipoxygenase and phospholipase A2) in a dose-dependent manner. The effects of EEK were generally comparable of those of EEA and EGCG. Therefore,E. kuromeand the components in EEK have the benefit of being used not only in common foods, but also more widely as a functional food resource in anti-allergic foods. [ABSTRACT FROM PUBLISHER]

In this study, we developed a reversed-phase high-performance liquid chromatographic method with fluorometric detection for the simultaneous quantitation of 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE) in foods by using 1,3-cyclohexanedione reagent. This method provides good resolution and reproducibility. Chromatography is conducted with a gradient system using a mobile phase of methanol–water–tetrahydrofuran (75:25:1, v/v) (A) and acetonitrile (B). The gradient employed is 5% B to 25% B in 25 min; 25% B to 80% in 30 min; isocratic at 80% B in 40 min. The flow rate is 1.0 mL/min. Fluorescence detection is performed at an exciting wavelength of 385 nm and an emission wavelength of 450 nm. The calibration curves for HHE and HNE concentrations are linear from 0.08 to 14 and 0.08 to 5.2 µmol/mL, respectively. The limits of detection and quantitation for HHE are 27 and 160 nmol/mL and those for HNE are 30 and 149 nmol/mL, respectively. Validation data show that the assay is sensitive, specific, accurate, and reproducible for the simultaneous quantitation of HHE and HNE. This rapid method is, therefore, appropriate for quantitating HHE and HNE in fatty foods such as fish and animal meats. [ABSTRACT FROM PUBLISHER]