The aim of this study was to evaluate the effects of temperature and storage time on the formation of biogenic amines (BAs) in the traditional Czech curd cheese (Olomoucké tvarůžky). Samples were stored for 7 weeks at 5 °C and 20 °C. BAs were studied as dansyl derivatives by the RP-HPLC method with fluorescence detection, histamine was determined using a photodiode array detector. Physical and chemical properties were analyzed as specified by the Czech National Standard, as were the sensory characteristics (colour, odour, texture and flavour). The major amines found were cadaverine (124-2 413 mg·kg -1 ) and tyramine (117-1 058 mg·kg -1), followed by putrescine (75-767 mg·kg -1) and histamine (74-411 mg·kg -1 ). Low concentrations of tryptamine, spermine and spermidine were present. Total concentrations of BAs significantly increased with storage time (P  0.01), depending significantly on temperature (P  0.01). Total BAs in cheese stored at 20 °C compared to 5 °C were more than three times higher, reaching 4 600 mg·kg −1 at the end of storage. The toxicologically critical value of 900 mg·kg −1 for the sum of histamine + tyramine + putrescine + cadaverine was reached 17 days later in the cheese stored at 5 °C compared to 20 °C. When stored at 5 °C, the samples retained adequate sensory characteristics for the entire safe storage time. The effects of storage conditions on BAs formation are relevant to reducing the risk associated with consumption of cheese high in BAs.

The aim of the study was to investigate the effects of two modified atmospheres with a different combination of gases on selected groups of microorganisms and on concentrations of biogenic amines (BAs) in samples of poultry breast muscle. The samples were packaged under modified atmosphere A (75% O 2 a 25% CO 2 ) or B (75% N 2 and 25% CO 2 ) and stored at temperatures from +2 to +4 °C for 14 days. During the storage period, O 2 concentrations in modified atmosphere A (MA A) decreased from the initial 74.8 ± 0.3% to 55.9 ± 6.6% at the end of the storage period. In all samples, counts of psychrotrophic bacteria counts, Brochothrix thermosphacta, lactic acid bacteria and coliform microorganism were determined. The tests were made on the packaging day, and then after three, nine and fourteen days of storage. At the end of the storage period, higher numbers of psychrotrophic bacteria (6.5 ± 0.7 log 10 cfu·g -1 ), Brochothrix thermosphacta (4.8 ± 0.3 log 10 cfu·g -1 ) and lactic acid bacteria (1.7 ± 0.4 log 10 cfu·g -1 ) were found on samples packaged under MA A. Samples packaged under modified atmosphere B on the other hand contained higher numbers of coliform bacteria (4.1 ± 0.6 log 10 cfu·g -1 ) at the end of the storage period. In addition to microbiological indicators, concentrations of biogenic amines (putrescine, cadaverine, histamine, tyramine, spermine, spermidine and β-phenylethylamine) were also determined. In fresh samples and after three days of storage, only spermine and spermidine were found. After 9 and 14 days, also other BAs were detected. The biogenic amine totals at the end of the storage period was 60.0 ± 13.2 mg·kg -1 in samples packaged under MA A and 129.0 ± 41.3 mg·kg -1 in samples packaged under MA B. The most abundantly represented biogenic amines in samples packaged under MA A were putrescine and spermine (49.7 and 24.8%, respectively, at the end of the storage period), and putrescine and cadaverine in samples packaged under MA B (47.0 and 32.9 %, respectively, at the end of the storage period).

Kameník J., Saláková A., Bořilová G., Pavlík Z., Standarová E., Steinhauser L. (2012): Effect of storage temperature on the quality of dry fermented sausage Poličan. Czech J. Food Sci., 30: 293-301.The influence of different storage temperatures (5°C and 15°C) on the quality of vacuum-packed dry fermented sausage Poličan was determined. The salami mixture, finished salamis (the maturing period of 30 days), and salamis stored for 30, 60, 90, and 120 days were analysed. The analyses performed (physical/chemical, sensory, microbiological) found no differences in sensory properties or basic physical/chemical and microbiological parameters in the products after storage under different temperature conditions for 120 days. When stored at 15°C, the total content of biogenic amines in samples was higher than that for samples stored at 5°C with statistical differences P ≤ 0.05. If the principles of good manufacturing practice are observed at all phases of the technological process, the storage temperature of 15°C does not represent a risk as the consequent concentration of biogenic amines and polyamines remains extremely low.

Abstract:We evaluated the effect of some factors (batch, producer, storage and amine distribution in cheese) on the biogenic amines and polyamines contents and microbial counts (Enterobacteriaceae, enterococci, lactic acid bacteria) in blue-veined cheese Niva. The tyramine content was increasing (P < 0.01) with storage time; at storage day 29, it reached 298 mg/kg and exceeded the toxicological limit. Cadaverine and the sum of biogenic amines also increased significantly (P < 0.01) and the latter reached up to 900 mg/kg, i.e. the established toxicological limit. The contents of the quantitatively most important biogenic amines (tyramine and cadaverine) and sum of biogenic amines varied according to batch and producer in the ranges of 3.0-337 mg/kg, 3.0-705 mg/kg, and 33-920 mg/kg, respectively. Considerably higher (P < 0.01) contents of tyramine, cadaverine and sum of biogenic amines and higher counts of enterococci and Enterobacteriaceae were found in the edge samples in comparison with the cheese core. The microorganisms were identified as E. faecalis and E. faecium.