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bstract Batches of gutted Mediterranean hake ( Merluccius merluccius var. Mediterraneus) were stored, in different seasons of the year, for up to 20 d in ice. Changes in trimethylamine (TMA-N), total volatile bases (TVB-N), P-ratio and trimethylamine oxide (TMAO) were measured; sensory evaluation of raw and cooked hake samples was also carried out. Similar profiles were observed between the different trials for all the parameters studied. TVB-N was not correlated with the time of ice storage, and proved to be better as a spoilage index than a freshness one. In contrast, TMA-N appears to be a good index of hake quality, and the value of 5 mg/100g offish seems an appropriate limit of acceptability. P-ratio was a poorer index of freshness than was TMA-N. [ABSTRACT FROM AUTHOR]

Biogenic amines and polyamines were measured in unripened cheese and 4 types of ripened cheese. The study included cheeses produced from both pasteurized and raw milks. All amines were lower in unripened than in ripened cheeses. The amine contents varied among different types of ripened cheese, within the same type of cheese, and also within the parts of cheeses. The main amines in ripened cheeses were tyramine, cadaverine, and putrescine. The highest concentration of tyramine was found in hard-ripened raw-milk cheeses, while blue cheese had the highest level of cadaverine. Unripened cheeses could be considered as well-tolerated products for histamine- and tyramine-sensitive individuals, whereas the wide variability in biogenic amines makes it difficult to generalize this consideration for all ripened cheeses. [ABSTRACT FROM AUTHOR]

A Quality Index Method for the sensory assessment of freshness of Mediterranean hake was developed and validated by sensory, chemical, and microbiological parameters. The Quality Index was the ratio between the overall sensory score obtained and the total achievable sensory score of the scheme and ranging 0 (fresh) to 1 (spoiled). This index increased significantly along the time of ice storage, allowing prediction of the remaining shelf life of hake. A value of 0.60 to 0.65 was estimated by statistical treatment as the rejection value, being concordant with sensory score of cooked hake, trimethylamine content, pH, as well as with legal regulations for mesophylic and enterobacteria counts. [ABSTRACT FROM AUTHOR]

BSTRACT: The formation of biogenic amines in goat cheese can be prevented through ensuring hygiene in raw materials and during manufacture, thereby avoiding potential decarboxylating microorganisms. High-pressure treatment may be used to inactivate microorganisms and is a potential alternative to pasteurization. This treatment could provoke higher proteolysis than pasteurization, leading to a higher availability of biogenic amine precursors. We compared the biogenic amine profile throughout the ripening of goat cheese made from pressurized milk with that obtained from pasteurized milk. Results indicate that the profile of biogenic amines is very similar for both cheeses. Tyramine was the prevailing amine in both cheeses, followed by cadaverine, putrescine, and histamine. [ABSTRACT FROM AUTHOR]

BSTRACT: The main amines in frozen and fresh hake (Merluccius merluccius) are the natural polyamines, spermidine. The levels of volatile and nonvolatile amines during storage of hake were strogly dependent on temperature. In samples stored at -20° only changes in dimethylamine and agmatine were found, whereas major changes were observed in samples stored at higher temperatures. Cadaverine was the major amine formed followed by histamine, putrescine and tyramine. The maximum levels of biogenic amines were lower than those reported for other fish species. Trimethylamine and biogenic amines related to hake spollage showed levels higher in fresh than in frozen samples, whereas levels of natural polyamines were not statistically different. [ABSTRACT FROM AUTHOR]

Data were obtained on histamine and tyramine contents in 48 samples of preserved and semi-preserved Spanish fish products. Ranges of concentration for both amines were wide: from 1.35 to 219.20 mg/ kg for histamine, and from 0.5 to 66.40 mg/kg for tyramine. Higher concentrations were found in semi-preserved anchovies than in the rest of the samples studied: canned tuna, herring, mackerel and sardines. In semi-preserved anchovies stored at room temperature (18-22°), histamine production was observed after 6 months. The increase in histamine was not observed in the samples stored under refrigeration (4-6°). Tyramine did not increase at either temperature of storage. [ABSTRACT FROM AUTHOR]

The formation of biogenic amines (histamine and tyramine) during Engraulis encrasicholus storage and spoilage was studied and compared with changes of other fish spoilage indicators: trimethylamine nitrogen, volatile basic nitrogen, hypoxanthine and pH. Good correlations were observed between biogenic amines and the other indicators, at both refrigeration (4-6°C) and room temperature (18-22°C).Two trials were carried out at each temperature. Differences were observed in levels of biogenic amines as well as other indicators in experiments carried out under similar conditions. [ABSTRACT FROM AUTHOR]