Uso do açafrão (Curcuma longa L.) na redução da Escherichia coli (ATCC 25922) e Enterobacter aerogenes (ATCC 13048) em ricota

Abstract

Considering the cheese involvement as a vehicle of pathogenic microorganisms it was evaluated the eficciency of the ethanolic turmeric extract added to ricotta, in the reduction of Escherichia coli and Enterobacter aerogenes. Three lots of creamy ricotta were manufacturated and inoculated with 104 UFC/mL of Escherichia coli (ATCC 25922) and 105 UFC/mL of Enterobacter aerogenes (ATCC 13048). It was added 0,4% of NaCl and ethanolic turmeric extract into concentrations that varied from 0.0% to 2.0% into the ricotta. The ricottas were evaluated in 0, 1, 7, 14 and 21 days under refrigerated storage. The ricotta moist percentage was of 73% in average. The average pH observed was of 5,4 and the fat percentage was of 3%. Microbiological results have shown a reduction in the number of Escherichia coli, after 21 days, about two logarithms cycles in treatments which 0.5%, 1.0%, 1.5% and 2.0% of ethanolic turmeric extract was used. As to Enterobacter aerogenes there was less reduction, at about one logarithm cycle, from 105 UFC/mL to 104 UFC/mL, also in treatments in which 0.5%, 1.0%, 1.5% and 2.0% of ethanolic turmeric extract was used. Although the results have shown a reduction in the number of the viable cells of the microorganisms evaluated, the ethanolic turmeric extract cannot be the single preservative means, considering a initial contamination of 104 UFC/mL of Escherichia coli and 105 UFC/mL of Enterobacter aerogenes for that would not be according to the current legislation referring to the microbiological cheese requirements.