Packaging method and storage temperature affects microbiological quality and content of biogenic amines in Agaricus bisporus fruiting bodies

Packaging type and storage temperature effects on the microbiological quality and biogenic amine content in Agaricus bisporus fruiting bodies were studied. The products stored in perforated packaging had significantly higher average total counts of bacteria, moulds and yeasts and Entembacteriaceae than those packed in modified atmosphere (30% CO2, 70% N-2). All of these indicators had significantly higher values at 19 +/- 1 degrees C than at 7 +/- 1 degrees C. It was found that storage of fruiting bodies in perforated packaging at both temperatures as well as in a modified atmosphere packaged at 7 degrees C resulted in a reduction in the total content of biogenic amines. However, 4 days of storage at 19 degrees C of MAP packaged material led to a more than 3-fold increase in their content compared to the fresh one. It was mainly caused by the synthesis of phenylethylamine, cadaverine, putrescine and to some extent histamine. Spermine was not found. Although the modified atmosphere better protects Agaricus bisporus fruiting bodies against the growth of microorganisms, a lower average level of biogenic amines was found when stored in perforated packaging.