Control of brucella organisms during manufacturing of acid cheese using some organic acids

Kariesh cheese is a highly nutritive soft acid cheese made from naturally fermented skimmed milk, mainly manufactured at home by small holders and sold at local markets. Due to unhygienic condition during manufacturing and low quality raw milk, many outbreaks of human brucellosis were reported. This study was done to evaluate the use of acetic and citric acids, as natural organic acids, to produce kariesh cheese instead of the traditional method to control Brucella infection. Sensory evaluation revealed that all treatments didn't differ (P>0.05) than control except 2% citric acid which characterized to a little extent by lemon flavor, crudeness body and texture and less whiter color than other treatments. B. meletensis strains didn’t affected by acetic (1%) or citric (1.5%) acids, but both of them were completely inhibited by acetic (1.5%), or have 4 log reduction by citric (2%) acids.  For B. abortus thefield and S19 strains were completely inhibited by 1% acetic acid, but citric acid 2% significantly (P<0.05) reduced the count of S19 and 544 strains by 4.46 and 3.32 log cfu/g, respectively. These results suggested that treatment of raw skimmed milk with acetic acid 1.5% or citric acid 2% is a good alternative for production of hygienic kariesh cheese to control brucellosis in human.