Modeling the effect of Croton blanchetianus Baill essential oil on pathogenic and spoilage bacteria.

This study aimed to evaluate and model the antimicrobial action of different concentrations of Croton blanchetianus essential oil (CBEO) on the behavior of six bacterial species in vitro. CBEO extraction was performed by hydrodistillation and characterized by CG-MS. CBEO solutions in culture media were tested at 0.90, 1.80, 2.71, and 4.51 mg of CBEO/mL, against foodborne bacteria: pathogenic bacteria (Staphylococcus aureus, Listeria monocytogenes and Salmonella Enteritidis at 35 °C), a non-pathogenic Escherichia coli (at 35 °C), and spoilage bacteria (Weissella viridescens and Leuconostoc mesenteroides at 30 °C). The CBEO major compounds were eucalyptol, α-pinene, sativene, E-caryophyllene, bicyclogermacrene, and spatulenol. Baranyi and Roberts (growth) and Weibull (inactivation) primary models, along with power and hyperbolic secondary models, were able to describe the data. CBEO inactivated L. monocytogenes, S. aureus, L. mesenteroides and W. viridescens at all applied concentrations. CBEO did not inactivate S. Enteritidis and E. coli, but their growth rates were reduced.

Noni (Morinda citrifolia L.) fruit as a new source of milk-clotting cysteine proteases.

This work reports the characterisation of caseinolytic and milk-clotting activities of proteases extracted from ripe fruits of Morinda citrifolia L., as a potential of their use in cheese production. Noni puree extract (NPE) was obtained by homogenising the fresh puree in 150 mM NaCl/50 mM sodium phosphate buffer (pH 7.0). The resulting protein concentration was of 0.367 ±â€¯0.006 mg/mL, and an electrophoretic profile of the extract revealed protein bands ranging from 14 to 55 kDa. The proteolytic activity of NPE was higher when the extract had been previously incubated at pH 6.0 (8.859 ±â€¯0.216 U/mg), whereas the optimum caseinolytic activity was observed at 50 °C. Noni puree proteases were strongly (98%) inhibited by iodoacetamide and E-64, suggesting the presence of only cysteine proteases in the crude extract. NPE proteases showed a milk-clotting activity (MCA) of 238.80 ±â€¯5.29 U/mL, a specific milk-clotting activity (SMCA) of 9950.17 ±â€¯220.74 U/mg, and an SMCA/PA ratio of 1124.31 ±â€¯24.94, this last being comparable to those of commercial calf rennet. The cheese manufactured using NPE presented brittle and soft texture, high humidity, and showed sanitary conditions compatible with current Brazilian regulations. The product showed a slightly bitter taste, but still good acceptability, rating between 6 and 7 in the hedonic scale for flavour, texture, and overall acceptance. Lastly, there was 60% of positive purchase intent, demonstrating that noni fruit is a promising source of milk-clotting enzymes for the dairy industry.

[Salmonella sp and Listeria monocytogenes in fully cooked ham commercialized in supermarkets of Fortaleza (CE, Brazil): risk factor for public health]. / Salmonella sp e Listeria monocytogenes em presunto suíno comercializado em supermercados de Fortaleza (CE, Brasil): fator de risco para a saúde pública.

The objective of this work was to evaluate the occurrence of Salmonella sp. and Listeria spp. in fully cooked ham without fat cover, stored under refrigeration, commercialized in supermarkets of Fortaleza (CE, Brazil). Forty samples of cooked ham, proceeding from eight trademarks, collected in 26 establishments, were analyzed according to the APHA and HBP for Salmonella sp. and Listeria spp. detection, respectively. Thirty percent of the samples were contaminated with Salmonella sp. and 42.50%, 22.50% e 2.5% with L. monocytogenes, L. innocua e L. welshimeri, respectively. It was also observed imperfections in the application of good manipulation practices in the supermarkets freezer section. It was verify that 34.61%, 57.69% e 15.38% of the establishments presented some sample contaminated with Salmonella sp., L. monocytogenes and both microorganisms respectively, including the area inspected by the six Regionals Executive General Offices of Fortaleza. These data show the necessity of a quality control improvement in all parts of food systems as an essential factor in the prevention of foodborne diseases.