Investigation of antimicrobial properties of bitulincontaining extract in milk products

The sum of triterpenoids from birch bark is the efficient bacteriostatic substance in relation to such microorganisms, as Bacillus subtilis, Staphylococcus aureus, Bacillus antracoides, Escherichia coli and Salmonella typhimurium, as well as it inhibits the growth of Candida albicans, Aspergillus niger and some others. The preliminary studies of preserving properties of dry betulincontaining birch bark extract (BEB) in milk products have been conducted. The impact of BEB on the keeping quality of pasteurized milk drink - 3,2 % fat , kefir -1 % fat, quark - 9 % fat, processed cheese - 45 % fat, butter - 82,5 % fat has been studied. The different dosages of BEB were introduced into the milk products test samples with preliminary dissolving of the extract in fat phase. Acidity, organoleptic and microbiological indices (number of mesophilic aerobic and facultative anaerobic microorganisms (MAFAnM), E. coli, yeast, mold fungi, lactic acid bacteria were measured in the process of the products storage. The comparison of the test and control samples values of three products batches with different microbial contamination showed that BEB plays some preserving action exhibiting at introduction of the specific dosage in relation to E.coli, molds, MAFAnM that can promote increasing of milk products storage life. Preserving properties of BEB are exhibited in the best way in milk products possessing the least initial microbial contamination.

pasteurized milk drink, kefir, quark, butter, processed cheese, betulincontaining extract, antimicrobial properties, keeping quality