Browsing by Subject "Antimicrobial"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Application of antimicrobial treatments in a commercial simulation to reduce E. coli O157:H7 and Salmonella spp. in beef trim and in ground beef(2006-12) Harris, Deidrea D.; Miller, Markus F.; Brashears, Mindy M.; Brooks, Chance J.Pathogens are of great concern for processors for food safety issues and for economic reasons. While beef trimmings and ground beef are to be cooked by the consumer, the processor must recall the raw product if testing indicates the presence of Escherichia coli O157:H7. Processors have very few interventions for beef trimmings and ground beef. A limited amount of research has been completed to determine antimicrobial effects under commercially simulated conditions on beef trim to reduce pathogens. The objective of this study was to validate the effectiveness of acetic and lactic acids (2% and 5%), acidified sodium chlorite (1000 ppm), and sterile water in reducing pathogen levels in beef trim prior to and after grinding in a simulated processing environment utilizing a belt turning and spray application. The effectiveness of these interventions on Escherichia coli O157:H7 and Salmonella Typhimurium were determined prior to treatment and at the following processing points: 1) just after treatment (20 minutes); 2) just after grind (6 hours); and 3) 24 hours after anaerobic storage at 4°C. Trim was inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium, with an inoculation level of 1x105 cfu/g. Sensory preparation was similar to the experimental design above except none of the trim was inoculated with pathogens. The organoleptic properties were evaluated during short term refrigerated storage at 6 and 24 hours after preparation. Raw patties were packaged on a Styrofoam tray and displayed in a retail display case. Visual panelists were trained to determine beef color, color uniformity, percentage of discoloration and browning evaluations of the raw patties based on appearance and composition. Muscle luminance, redness and yellowness of the raw product were objectively measured using the Minolta Spectrophotometer. Triangle test were used for comparison of the control and treated samples at 6 and 24 hours after production. Panelists (n = 24) were given three coded samples, including two of the same sample and one odd sample. Panelists were asked to determine the odd or different sample. Results from this study indicate that all antimicrobial interventions, including sterile water, reduced pathogen loads (P < 0.05) for both Escherichia coli O157:H7 and Salmonella Typhimurium in ground beef by almost 1 log cycle. The antimicrobial treatments of: sterile water, 5% lactic acid, 2% acetic acid, 5% acetic acid, and acidified sodium chlorite (1000 ppm) significantly reduced Escherichia coli O157:H7 (P < 0.05) in ground beef. The antimicrobial treatments of: acetic and lactic acids (2% and 5%), acidified sodium chlorite (1000 ppm), and sterile water significantly reduced pathogen loads of Salmonella Typhimurium (P < 0.0001) in ground beef 6 and 24 hours after processing. Utilizing a triangle test there was no significant difference P < 0.05 in the mean of correct responses between controls, 2% lactic acid, 5% lactic acid, 2% acetic acid, 5% acetic acid and acidified sodium chlorite (1000 ppm) within treatment, 6 or 24 hours samples from a non-trained sensory panel.Item Efficacy of Consumer-Available Antimicrobials for the Disinfection of Pathogen Contaminated Green Bell Pepper and Efficacy of Consumer Cleaning Methods for the Decontamination of Knives(2011-08-08) Perez, Keila LizthLimited information exists regarding the efficacy of consumer-available antimicrobials for the use on produce surfaces. There is a strong focus on eliminating pathogens from produce at a commercial level, but consumers can achieve pathogen reduction in a domestic setting. The objectives were to determine the ability of consumer-available antimicrobials to disinfect waxed green bell peppers, determine the efficacy of knife cleaning methods, and assess the transfer of contamination. Peppers were inoculated via immersion in a cocktail of rifampicin-resistant Salmonella serovars and Escherichia coli O157:H7 to a final concentration of 5.6 ? 0.5 log CFU/cm2. In study 1, samples of 3 10-cm2 pieces of inoculated pepper were excised from smooth tissue and immersed in 3% (v/v) hydrogen peroxide (H2O2), 2.5% (v/v) acetic acid, 70% (v/v) ethyl alcohol (EtOH), or sterile distilled water (SDW) for various lengths of time. Following treatment, samples were immersed for 30 s in a neutralizer solution. For study 2, inoculated peppers were chopped into 1-cm2 pieces. Knives were treated with one cleaning method: no treatment (control), towel wipe (TW), running hot water for 5 s (5SW), running hot water for 10 s (10SW) or 1% (v/v) detergent solution followed by hot running water for 10 s (ST). After treatments, knives were used to chop cucumbers. Surviving Salmonella and E. coli O157:H7 for both studies were selectively enumerated on lactose-sulfite-phenol red-rifampicin agar following aerobic incubation of plates for 24 h at 35 ?C. Hydrogen peroxide exposure for 5 min resulted in reductions of 1.3 ? 0.3 log CFU/cm2 for both pathogens. Following 1 min exposure to EtOH, pathogens were reduced by 1.3 ? 0.1 3 log CFU/cm2; exposure for >1 min did not result in additional reduction. Acetic acid exposure after 5 min resulted in a Salmonella reduction of 1.0 ? 0.7 log CFU/cm2, but for E. coli O157:H7, exposure resulted in no significant reduction (p<0.05) of pathogens compared to SDW at the various points. For study 2, 5SW, 10SW, and ST were equally effective for knife decontamination. No significant difference (p<0.05) was found between log CFU/cm2 on knife blade and log CFU/cm2 transferred to surface of cucumber; therefore, viable organisms remaining on the knife blade were transferred onto the surface of the cucumber. Findings suggest EtOH and H2O2 may be effective consumer-deployable antimicrobials for surface decontamination of smooth produce, and contaminated produce can contaminate other produce. Further research of antimicrobial exposure on produce sensorial characteristics is also advised in order to determine how various antimicrobial exposure times will affect the quality and sensorial characteristics of the produce commodity.Item The Effect of Thymol-B-D-Glucopyranoside on the Reduction of Campylobacter Species in Food-Producing Animals(2013-06-06) Epps, Sharon V.R.Campylobacter are a leading cause of bacterial derived foodborne illness. Thymol is a natural product that reduces survivability of Campylobacter in vitro. Results from animal studies, however, indicate that absorption or degradation within the stomach and small intestine may preclude delivery of thymol to the cecum and large intestine, the main sites of Campylobacter colonization. Presently, we compared the anti- Campylobacter activity of thymol against that of thymol-?-D-glucopyranoside (?-Dthymol), the latter suspected to be resistant to degradation and absorption in the proximal alimentary tract lacking ?-glycosidase activity. When treated with 1 mM thymol, the survivability of Campylobacter coli and jejuni in vitro was reduced by 3.41 to 6.87 log_10 CFU mL-1 after 48-h pure culture and after co-culture, respectively. In the presence of a ?-glycosidase-expressing Parabacteroides distasonis. Conversely, the survivability of C. coli and C. jejuni was reduced by 3.72 and 4.30 log_10 CFU mL-1, respectively, in cocultures treated with ?-D-thymol, but not in pure cultures similarly treated. When tested in mixed cultures of porcine or bovine fecal microbes possessing endogenous ?- glycosidase, C. coli and C. jejuni survivability was reduced by 3.26 and 2.50 log_10 CFU mL-1, respectively, whether treated with thymol or ?-D-thymol. In mixed populations of avian crop and cecal microbes, C. jejuni survivability was reduced 1.41 to 2.32 log_10 CFU mL-1 whether treated with thymol or ?-D-thymol. Thymol and ?-D-thymol inhibited ammonia accumulation in mixed populations of porcine and mixed bovine fecal microbes which is consistent with free thymol?s purported role as a deaminase inhibitor. Conversely, thymol and ?-D-thymol did not affect ammonia accumulation in mixed populations of avian gut microbes implicating population specific effects of these compounds. ?-D-thymol, but not thymol, reduced accumulation of fermentation acids indicating the conjugate inhibited fermentation which may limit its application to the last meal or last few meals before harvest. Oral administration of 150 ?mol ?-D-thymol reduced C. jejuni in avian crop, but not in cecal contents; treatment with thymol was ineffective. These results indicate that ?-D-thymol, or similar ?-glycosides, may be a suitable candidate to escape absorption and degradation within the proximal alimentary and retain its anti-Campylobacter properties. Further research is needed to reduce such technology to practice.