EFFECTIVENESS OF CALCIUM PREPARATION TO CONTROL MICROBIAL-GROWTH IN FOOD

Inhibitory effects of a calcium preparation on the growth of food-born e bacteria and yeast were investigated, and its application to food wa s advanced. The calcium preparation was made from oyster shells, and t hen treated electrically with ohmic heating. This product has been alr eady used as a nutrient supplement. Chemical analysis showed that this preparation contained mainly calcium and other minor elements. The mi nimum inhibitory concentration (MIC) to bacterial growth was measured. This preparation and its major component Ca(OH)2 showed almost the sa me MICs in the range of 0.07 to 0.1%. Both Gram-positive and negative bacteria were inhibited at the same concentrations. In the case of NaO H or KOH, MICs ranged from 0.09 to 0.15% or from 0.15 to 0.24%, respec tively. Yeasts were inhibited at the lower concentrations than bacteri a. Viable cell number in food decreased or did not increased by additi on of the calcium preparation. Bacillus, Escherichia, Salmonella and S taphylococcus inoculated to food were suppressed their growth by the c alcium preparation. The calcium preparation was more effective than Ca (OH)2 to get the same effects. It was shown that the calcium preparati on used as a nutritional additive could be applied to control the micr oorganisms in food. Also, the possibility of utilizing the alkaline ra nge to keep the quality of food was suggested.