A new high-sensitivity, low-cost, Surface Enhanced Raman Spectroscopy (SERS) sensor allows for the rapid multiplex detection of foodborne pathogens in raw poultry. Self-assembled microspheres are used to pattern a hexagonal close-packed array of nanoantennas onto a side-polished multimode fiber core. Each microsphere focuses UV radiation to a photonic nanojet within a layer of photoresist on the fiber which allows the nanoantenna geometry to be controlled.
View Article and Find Full Text PDFA validation study was conducted to investigate the effect of the English muffin baking process to control Salmonella contamination and to study the thermal inactivation kinetic parameters (D- and z-values) of Salmonella in English muffin dough. The unbleached bread flour was inoculated with 3 serovar Salmonella cocktail (Salmonella serovars viz., Newport, Typhimurium, and Senftenberg), and dried back to its preinoculated water activity levels with 7.
View Article and Find Full Text PDFA study was conducted to validate a simulated traditional crust pepperoni pizza baking process to control Shiga toxin-producing (STEC) and to determine the heat resistance characteristics of STEC in pizza dough. Pizza dough and pepperoni slices were inoculated with 7 strains STEC cocktail and baked at 500°F (260°C) for 12 min using a conventional kitchen oven followed by 15 min of ambient air cooling. The mean internal temperature of the pizza reached 209.
View Article and Find Full Text PDFFoodborne pathogens like Salmonella and Escherichia coli O121 can endure the harsh low water activity (a) environment of wheat flour for elongated periods of time and can proliferate when hydrated for baking or other purposes. This study determined the survivability and thermal tolerance (D- and z-values) of Salmonella and Escherichia coli O121 in wheat flour and muffin batter (prepared from inoculated flour on the days of analyses) during the storage period of 360 days. The Salmonella and E.
View Article and Find Full Text PDFThis study validated a simulated commercial baking processes for hard and soft cookies to control Salmonella, and determined D- and z-values of 7-serotype Salmonella (Newport, Senftenberg, Tennessee, Typhimurium, and three isolates from dry pet food) cocktail in cookie doughs. Cookie doughs were prepared using flour mist-inoculated with the Salmonella cocktail. Hard and soft cookies were baked at 185 °C for 16 min and 165.
View Article and Find Full Text PDFPathogens, such as and , can survive under the dry environment of flour for extended periods of time and could multiply when flour is hydrated to prepare batter or dough. Therefore, inactivation of these pathogens during the cooking/baking step is vital to ensure the microbiological safety of bakery products such as brownies. The aim of this research was to validate a simulated commercial baking process as a kill-step for controlling and in brownies and to determine thermal inactivation parameters of these pathogens in brownie batter.
View Article and Find Full Text PDFThis study was conducted to validate a simulated commercial baking process for plain muffins against E. coli O121 (isolated from the recent illness outbreak associated with flour), and compare the thermal inactivation parameters (D- and z-values) of cocktails of four isolates of E. coli O121 and three serovars of Salmonella (Newport, Typhimurium, and Senftenberg) in muffin batter.
View Article and Find Full Text PDFThis study was conducted to validate a simulated commercial whole wheat multigrain bread baking process at 375 °F (190.6 °C) oven temperature for 35 min to inactivate Salmonella, and to determine the thermal inactivation parameters of a 7-serovar Salmonella cocktail in whole wheat multigrain bread dough. A ≥5-log CFU/g reduction in Salmonella population was achieved by 15 min, and no viable Salmonella was detected after enrichment plating by 16 min.
View Article and Find Full Text PDFThis study was conducted to validate a commercial nut muffin baking process and to compare the survival of a 7-serovar Salmonella cocktail when contaminated via inoculated flour or walnuts. Enriched wheat flour or walnut pieces were mist inoculated with the Salmonella cocktail and dried back to the pre-inoculation weight, resulting in a Salmonella population level of 6.9 and 8.
View Article and Find Full Text PDFFoodborne Pathog Dis
December 2018
This study validated a typical commercial donut frying process as an effective kill-step against a 7-serovar cocktail (Newport, Typhimurium, Senftenberg, Tennessee, and three dry food isolates) when contamination was introduced through inoculated flour. The bread and pastry flour mix (3:1) was inoculated with the cocktail, and subsequently dried back to original preinoculation moisture content, achieving a population of 7.6 log CFU/g.
View Article and Find Full Text PDFThis research investigates the potential risk of Salmonella in muffins when contamination is introduced via flour, the main ingredient. Flour was inoculated with a 3-strain cocktail of Salmonella serovars (Newport, Typhimurium, and Senftenberg) and re-dried to achieve a target concentration of ~8logCFU/g. The inoculated flour was then used to prepare muffin batter following a standard commercial recipe.
View Article and Find Full Text PDFThis study was conducted to validate a simulated commercial baking process for hamburger buns to destroy Salmonella serovars and to determine the appropriateness of using nonpathogenic surrogates (Enterococcus faecium ATCC 8459 or Saccharomyces cerevisiae) for in-plant process validation studies. Wheat flour was inoculated (∼6 log CFU/g) with three Salmonella serovars (Typhimurium, Newport, or Senftenberg 775W) or with E. faecium.
View Article and Find Full Text PDFA total of 154 enterococcal isolates from 95 stored-product insects collected from a feed mill, a grain storage silo, and a retail store were isolated and identified to the species level using PCR. Enterococcus casseliflavus represented 51% of the total isolates, followed by Enterococcus gallinarum (24%), Enterococcus faecium (14%), Enterococcus faecalis (7%), and Enterococcus hirae (5%). Many isolates were resistant to tetracycline (48%), followed by streptomycin (21%), erythromycin (14%), kanamycin (13%), ciprofloxacin (12%), ampicillin (4%), and chloramphenicol (<1%).
View Article and Find Full Text PDFLaboratory experiments were designed to determine the survival of Enterococcus faecalis OG1RF:pCF10 in poultry and cattle feed and its acquisition and transmission by adults of the red flour beetle, Tribolium castaneum (Herbst), to sterile feed. Adult T. castaneum beetles were introduced into poultry and cattle feed inoculated with E.
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