Examinando por Autor "Miller, Markus"

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    "Assessment of Microbial Indicator Loads and Salmonella spp. prevalence using MicroTally on Beef Carcasses in a Commercial Processing Facility
    (Zamorano: Escuela Agrícola Panamericana, 2024) Paz M., Nadia I.; Acosta, Adela; Miller, Markus
    This study aimed to research the microbial contamination on beef carcasses in a commercial processing facility using two MicroTally® Mitt procedures for sampling. The primary objective was to evaluate the microbial loads of aerobic counts (AC), Enterobacteriaceae (EB), and Escherichia coli (EC) at various processing stages and compare the effectiveness of dry versus pre-moist sampling methods. Samples were collected from different carcass parts, at different stages and locations including the hide, pre-evisceration, post-evisceration, cold carcass, chuck, trim, and final rail. For the microbial analysis, the TEMPO® system was used for enumeration. The results demonstrated variations in microbial loads across different processing stages and sampling methods. Post-evisceration premoisten bacteria load is significantly difference (P < 0.05) from the dry sampling method for AC, EB, and EC. Moreover, no significant was shown between the treatments in the other stages and locations. However, a significant interaction between treatments and areas was found on AC and EC, indicating that effectiveness varied depending on the area. The investigation demonstrates the presence of the microorganisms at different sample points during the processing line by using MicroTally® Mitt. The findings contribute to improved microbial monitoring and management practices in beef processing facilities to ensure food safety and quality.
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    Ítem
    In Plant Assessment of Lactic Acid Intervention in Variety Meats Through the Beef Processing Line
    (Zamorano: Escuela Agrícola Panamericana, 2020, 2020) Moya A., Eduardo J.; Acosta, Adela; Miller, Markus
    Beef industries continuously seeks interventions that may reduce bacterial loads in their products to increase shelf life and ensure beef product wholesomeness. This in-plant validation study was conducted to evaluate the effect of spray lactic acid interventions in beef variety meats. Lactic acid solution (2 to 5%) was applied to variety meats by spray application ≥ 103.42 kPa for 5 s. Samples were collected in plant during the processing line by swabbing 500 cm2 surface area of meat before and after lactic acid applications. A total of 108 samples were collected (54 before and 54 after) for beef liver, cheek, and heart. All samples were shipped to Texas Tech University´s food Microbiology laboratory for microbiological analysis. Composites of three samples were made by adding 3 mL of each sample to a sterile test tube until reaching 9 mL. All composites were serially diluted and plated to determine total aerobic plate counts (APC), coliform counts and generic E. coli counts using 3M APC Petrifilm, 3M Coliform/E. coli Petrifilm, respectively. Duplicates were made of each Petrifilm and were incubated at 37 °C. All samples were converted to CFU per cm2 before statistical analysis. Treatment with lactic acid (2-5%) spray was lower (P < 0.005) in APC, generic E. coli and total coliforms microbial loads after the intervention on beef cheek, heart, and liver. Therefore, lactic acid (2-5%) spray intervention reduces Aerobic Plate Count, Total Coliforms and generic E. coli in beef cheeks, heart, and liver in the processing line.
  • Miniatura
    Ítem
    The effect of PhageGuard intervention on Escherichia coli O157:H7 applied to beef hides
    (Zamorano: Escuela Agrícola Panamericana, 2023) Martinez G., Andres I.; Miller, Markus; Brashears, Mindy
    An in-plant study was conducted to assess the antimicrobial effectiveness of the Phage Guard intervention against E. coli O157:H7 in cattle stalls before slaughter. The reduction in microbial surface area was evaluated by collecting 500-600 cm2 hide samples from the cleanest area of the cattle during slaughter at the Gordon W. Davis Meat Laboratory. Three replicates, each comprising nine beef hide samples, were obtained. These samples were inoculated with an E. coli O157:H7 cocktail via spray application. Throughout the study, periodic collections of inoculated hide samples were performed, and bacterial loads were quantified using the Drop Dilution method and TEMPO System. The TEMPO System proved to be the most suitable and accurate method for quantifying E. coli O157:H7 on beef cattle hides. The study's findings revealed no significant differences between treatments. Potential factors contributing to this outcome included the chosen temperature and exposure time for the bacteriophage's optimal hatching, growth, multiplication, and lysis, typically 37 °C and 30 minutes. However, under the specified conditions, a substantial reduction in E. coli O157:H7 with the PhageGuard E product was not observed. In conclusion, the environmental temperature and exposure time (15 minutes), considering the minimum wait time for beef cattle before slaughter, were insufficient to produce significant reductions in bacteria.