Butia odorata Barb. Rodr. extract inhibiting the growth of Escherichia coli in sliced mozzarella cheese

Abstract

The aims of this study were to verify the occurrence of Escherichia coli in sliced mozzarella cheese marketed in Pelotas city, Brazil and perform the phenotypic and genotypic characterization of the isolates. Besides that, evaluate the susceptibility of E. coli to Butia odorata extract, characterize it chemically, and apply the extract in sliced mozzarella cheese contaminated experimentally with E. coli. Escherichia coli was isolated in 5% (4/80) of cheese samples, but no gene used as marker for E. coli O157:H7 or virulence genes were detected. The isolates were susceptible to B. odorata extract (MIC 15 mg mL -1 and MBC 29-58 mg mL -1 ), and the major compounds present in the extract were Z-10-Pentadecenol (80.1%) and Palmitic acid (19.4%). In cheese, after 72 h there was a significant difference between control (2.8 log CFU cm -2 ) and treated samples with MIC, 2 9 MIC, 4 9 MIC and 8 9 MIC (1.3, 1.4, 1.6 and 0.5 log CFU cm -2 , respectively). The isolation of E. coli in cheese indicates fecal contamination and poor hygienic practices. Butia odorata extract showed antimicrobial activity against E. coli both in vitro and in situ, indicating that it can be a good alternative for inhibiting the growth of this microorganism in sliced cheese.

Nutritional Composition and Bioactive Compounds of Native Brazilian Fruits of the Arecaceae Family and Its Potential Applications for Health Promotion

“…The antimicrobial potential of extracts obtained from butiá has been reported [ 188 , 189 , 190 ]. Maia et al [ 190 ] reported that the hexane extract of butiá (3 and 7 mg mL −1 ) presented activity against Gram-negative bacteria such as Salmonella Typhimurium , Escherichia coli O157: H7, and Pseudomonas aeruginosa ), with zones of inhibition ranging from 59.50 to 86.00 mm using the agar diffusion method.…”

“…Such behavior may be correlated to the cellular membrane of Gram-negative bacteria, which is composed of lipopolysaccharides ensuring protection against various agents. It has been reported that (+)-catechin, (−)-epicatechin, quercetin, and phytosterols present synergistic action against the Gram-negative bacterium [ 188 , 189 , 193 ].…”

“…The logarithmic decrease observed for the number of colony forming units (CFUs) of Escherichia coli in the samples treated with the extract after 72 h was eight times higher when compared to the control (2.8 log CFU cm −2 and 0.5 log CFU cm −2 , respectively). The authors associated the antimicrobial activity of the extract with the main compounds such as Z-10-pentadecenol (80.1%) and palmitic acid (19.4%), identified in the butiá extract [ 189 ].…”