Search

Amounts of volatile and biogenic amines, pH and microbial counts were monitored in Mediterranean anchovy (Engraulis encrasicholus) over 23 days of ice storage with the aim of examining their suitability as indicators of freshness. Counts of Enterobacteriaceae reached the maximum limits stipulated by Spanish regulations after 5 days of storage in ice, while those of mesophilic bacteria took 7 days. Levels of volatile amines hardly increased during ice storage. Amounts of biogenic amines did increase, though there were differences from one amine to the other. Cadaverine, the most abundant biogenic amine, showing the earliest increase, coinciding with the shelf-life time as determined through Enterobacteriaceae counts. Amounts of histamine remained below the maximum levels established by both European Union and Food and Drug Administration regulations. Other biogenic amines were found at much higher levels than histamine. Results demonstrated the suitability of the biogenic amine index (as the sum of histamine + tyramine + putrescine + cadaverine) as a freshness indicator for anchovies stored in ice, with a limit of acceptability set at 15 mg kg−1. Copyright © 2005 Society of Chemical Industry

Two infant milks claimed to have the same final composition in liquid and powdered form respectively were stored for 12 mo at 20, 30, and 37 °C. Vitamin E, thiamin, riboflavin, pyridoxine, folic acid, and nictoinamide remained constant at the three temperatures. However, there were statistically significant losses of vitamin A (approximately 35%) in samples stored at 37 °C. No differences were observed in vitamin stability between the two infant milks studied. Final levels of vitamin A were always higher than the minimum set by Spanish legislation. Vitamin A overfortification (approximately 200%) was more than that needed to compensate for losses during storage.

Biogenic amines (histamine, tyramine, β-phenylethylamine, serotonin, tryptamine, putrescine, cadaverine, agmatine, spermine and spermidine) in raw materials, worts and beers, and their evolution during brewing were studied using HPLC. Hop and especially malt contributed to amine contents in wort and beer. Amines were not detected in rice, used as adjunct cereal. High amine production was found during malting. Spermine and spermidine levels decreased sharply during mashing, while the other amines increased, except for putrescine that did not vary. No significant changes in formation of amines occurred during fermentation, except for tryptamine and tyramine. Tyramine formed ranged from 9.70 to 27.30 mg/L.

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.

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°C), histamine production was observed after 6 months. The increase in histamine was not observed in the samples stored under refrigeration (4-6°C). Tyramine did not increase at either temperature of storage.