The oxidation of fatty acids can be inhibited by engineering the surface of oil-in-water emulsion droplets to decrease interactions between aqueous phase prooxidants and lipids. The objective of this research was to evaluate whether emulsions stabilized by a multilayer emulsifier systems consisting of beta-lactoglobulin and citrus or sugar beet pectin could produce fish oil-in-water emulsions that had good physical and oxidative stability. Sugar beet pectin was compared to citrus pectin because the sugar beet pectin contains the known antioxidant, ferulic acid. A primary Menhaden oil-in-water emulsion was prepared with beta-lactoglobulin upon which the pectins were electrostatically deposited at pH 3.5. Emulsions prepared with 1% oil, 0.05% beta-lactoglobulin, and 0.06% pectins were physically stable for up to 16 days. As determined by monitoring lipid hydroperoxide and headspace propanal formation, emulsions prepared with the multilayer system of beta-lactoglobulin and citrus pectin were more stable than emulsions stabilized with beta-lactoglobulin alone. Emulsions prepared with the multilayer system of beta-lactoglobulin and sugar beet pectin were less stable than emulsions stabilized with beta-lactoglobulin alone despite the presence of ferulic acid in the sugar beet pectin. The lower oxidative stability of the emulsions with the sugar beet pectin could be due to its higher iron and copper concentrations which would produce oxidative stress that would overcome the antioxidant capacity of ferulic acid. These data suggest that the oxidative stability of oil-in-water emulsions containing omega-3 fatty acids could be improved by the use of multilayer emulsion systems containing pectins with low metal concentrations.

Shiga-like toxin-producing Escherichia coli (STEC) is an important source of food contamination that presents risks to human health. Several industrial food processes eliminate this microorganism; however, these processes can alter the characteristics of the product. Alternative methods of preservation have been identified as an option to control these foodborne pathogens. The purpose of this study was to evaluate the action of bacteriocins produced by Enterococcus durans MF5 in STEC cells. Cell-free supernatant (CFS) containing enterocins from the MF5 isolate was tested over different time points (6, 18, and 24 h). Enterocins present in the crude CFS showed inhibition against STEC at all time points. In the investigation of cell integrity, using propidium iodide and fluorescence microscopy, considerable cell death was observed within 6 h of the cells being in contact with the enterocins, which was also observed at the 18 and 24 h time points. These results showed that the enterocins produced by the MF5 isolate have potential use in the control of STEC.

<p>The artisan cheese production is an important income source for family farmers, however the lack of standardization and negligence in the preparation of the product generates a low quality cheese. The production of cheese of good quality finds some obstacles, because milk does not contribute in many ways to ensure the characteristics of the product. The aim of this study was to evaluate the physico-chemical characteristics of 20 Minas Frescal cheeses, of which 10 samples were artisanal and 10 have industrial production. The handmade cheeses were sold in street markets and all the samples had no labeling and sanitary inspection seal. The industrialized were obtained in supermarkets, all the 20 samples were acquired in Londrina-PR. The analyses performed were &nbsp;moisture, fat (d.b.), pH and acidity. The fat analysis showed that 50% of samples from artisanal cheeses and 40% of industrialized ones violate the current laws. The pH of artisanal cheese samples ranged between 5.2 and 6.7 and the acidity ranged between 0.06 and 2.41%. The variation in acidity showed that the cheeses are made without standard and quality control of raw material. In industrialized cheeses the pH ranged between 5.3 and 6.5 and acidity between 0.2 and 1.4%. With this work we concluded that the small producers and industries do not pay attention to physico-chemical parameters essential to the quality of the cheese.</p><p>&nbsp;</p><p>DOI: http://dx.doi.org/10.14685/rebrapa.v2i2.48</p>

The aims of this work were to identify and characterize for some important technological properties of the E. faecium throughout the ripening process of cheese. The study involved evaluating the technological potential of six isolates of E. faecium (EFM55, EFM67, EFM9A, EFM16A, EFM19A and EFM44) from artisanal cheeses as their probiotic characteristics and technological perspective. Concerning the antimicrobial sensibility, 71% of the E. faecium tested were sensitive to all antimicrobials. No other medicine inhibited the active of E. faecium, with the exception of dipyrone for the EFM19A and EFM9A strains. The isolates showed good antagonistic activity against gram-negative, as EFM9A, EFM55 and EFM67 strais with better activity. The highest fermentation was observed in 42 ºC, showed the pH variation of 4.15 to 5.15, after 48 hours of fermentation. All isolates showed pH reduction at 20 ºC. However, all isolates produced higher titratable acidity at a temperature of 42ºC. The isolates EFM55 and EFM9A has had probiotic actived, biochemical and susceptibility parameters desirables, aim it’s technological potential in the production of dairy products.

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