Combined Effect of Sodium Chloride and Clove on Growth and Biogenic Amine Formation of Enterobacter aerogenes in Mackerel Muscle Extract.

The inhibitory effects of clove (0.5%) and sodium chloride (1-5%) on the growth and biogenic amine (histamine and cadaverine) production of Enterobacter aerogenes in mackerel muscle broth at 30°C were investigated. At 1% level, sodium chloride was favorable for growth, whereas higher levels slightly reduced the growth in comparison to the control. The maximum population numbers obtained in the presence of sodium chloride were essentially the same as that of the control. Amine production was remarkably enhanced by the presence of 1 % NaCl alone. Only a little increase was observed for higher levels, and sodium chloride at more than 3% had no stimulatory effect on the amine formation. Addition of clove at a level of 0.5% to the broth resulted in a delay in the growth and the amine formation. The presence of NaCl as low as 2% in combination with clove (0.5%) completely inhibited the growth and amine production of E. aerogenes in mackerel broth. Synergistic effects of clove essential oils and sodium chloride could be considered as the probable reason for the inactivation of the bacterium.