Contagem de bactérias lácticas em iogurtes comerciais

Abstract

Yogurt is the definition given to milk derived from fermentation by mixed-milk Lactobacillus bulgaricus culture and Streptococcus thermophilus. The conservation of yogurt through the action of lactic acid bacteria in food occurs by the production of organic acids, especially with concomitant lactic acid acidi-fication to pH product around four. The acidification process promotes the inhibition of development of spoilage and pathogenic microorganisms. The Ministry of agriculture, livestock and food supply through normative instruction n° 46 of 2007 establishes the minimum amount viable for lactic acid bacteria. The present study had as objective the quantification of lactic acid bacteria as well as assess the acidity and pH in different brands and types of commercial yogurts. 28 yogurt samples were analyzed used, including 7 different, marketed in the city of Montes Claros-MG, physico-chemical analyzes of pH and titratable acidity. According to the obtained results it was possible to verify that, excepting the C sample at 7 and 14 days in that did not reach the minimum levels for acidity, all yogurts analyzed showed cha-racteristic pH of yogurts and acidity within the values allowed by the law and according to values found by other authors. In the count of lactic bacteria, all 7 brands analyzed were within the limit established by the law.