Inhibition of Listeria monocytogenes and Clostridium botulinum in Uncured Shredded Pork and Turkey Packaged Under Reduced Oxygen Conditions.

Cooked, uncured meat products packaged under reduced oxygen packaging conditions require the control of anaerobic and facultative anaerobic pathogens if they are held at temperatures greater than 3°C at retail or consumer level. The objective of this study was to determine the inhibition of Listeria monocytogenes and Clostridium botulinum in cooked, uncured shredded turkey and pork formulated with synthetic or clean-label antimicrobials. Treatments of shredded meat products were prepared with or without antimicrobials using turkey thigh or breast that were cooked to 85°C, shredded, and chilled before inoculation with the target pathogen. L. monocytogenes inoculated samples were stored at 7.2°C, whereas C. botulinum samples were stored at 12.8°C; triplicate samples were assayed every 2 weeks. In the first set of experiments, L. monocytogenes populations increased 2 to 3 logs within 2 weeks of storage at 7.2°C in both meat control treatments without antimicrobials and in pork with 4% lactate-diacetate blend (LD). A 1-log increase was observed in turkey with 4% LD and Pork with 2% cultured dextrose-vinegar-rosemary (CDVR) under the same storage conditions; a 1-log increase was observed in turkey with CDVR at 4 weeks. The second set of experiments tested the effect of pH reduction (to less than 5.5 by the addition of 0.5% citric acid) in combination with 2% CDVR when added to the brine precook or postcook during shredding. Populations of L. monocytogenes increased 4-log within 2 and 4 weeks at 7.2°C for the control turkey and pork formulations, respectively. No growth was observed in 12 weeks for any antimicrobial CDVR-CA treatments regardless of how antimicrobial was added. Similarly, botulinum toxin was detected in both control treatments at week 2 at 12.8°C, but no toxicity was observed in either antimicrobial treatment through 12 weeks. These data suggest that a combination of 2% cultured dextrose-vinegar-rosemary extract plus 0.5% citric acid to reduce pH inhibits the growth of L. monocytogenes and toxin production of C. botulinum in uncured shredded turkey and pork products stored under mild temperature abuse conditions for up to 12 weeks in reduced oxygen packaging.

Fatty Acid and Micronutrient Profile of Longissimus Lumborum from Red Angus and Red Angus x Akaushi Cattle Finished on Grass or Grain.

Cattle diet and breed modify the nutritional profile of beef. The objective of this study was to compare the fatty acid (FA) and micronutrient profiles of Red Angus (RA) and RA x Akaushi (AK) crossbreed steers fed either a grass or grain diet. This two-year study randomly assigned steers to the diets using a 2 × 2 factorial experiment. FAs and micronutrients were analyzed. Diet effect was the strongest with grass-finished beef being higher in n-3 polyunsaturated FAs (p < 0.001), conjugated linoleic acid (p < 0.05), vaccenic acid (p < 0.05), iron (p < 0.001), and vitamin E (p < 0.001) compared to grain-finished beef. Breed effects were observed for lauric and myristic acids (p < 0.05), selenium (p < 0.05), and zinc (p < 0.01) with AK containing more of these compounds than RA. Diet × breed effects were non-existent. These results indicate that diet has a stronger influence than breed on modifying the nutritional profile of beef. Because of a more favorable FA and antioxidant profile, consumption of grass-finished beef could benefit human health.

Assessment of Sanitation Practices for the Control of Listeria monocytogenes at Small and Very Small Ready-to-Eat Meat and Poultry Processors.

ABSTRACT: Science-based guidance was used at eight small and very small state and federally inspected ready-to-eat meat and poultry processors across Michigan. Data were collected to determine the current level of sanitary control methods used for reducing Listeria in the processing environment and compared interactions with the facility microbial results. A checklist was created to assess the current recommended sanitary control methods from the U.S. Department of Agriculture, U.S. Food and Drug Administration, and the Michigan Department of Agriculture and Rural Development. The checklist, composed of 178 items divided into 10 general content domains, was used to assess which of the recommended controls were being used in the facilities to prevent postlethality contamination of ready-to-eat products. Effectiveness of preoperational and operational sanitation was assessed through sampling 12 nonfood contact surfaces by using an ATP reader and amplified nucleic single temperature reaction test for Listeria spp., including L. monocytogenes, at each facility. In total, 288 samples were taken collectively from the eight facilities (96 ATP, 96 preoperational Listeria spp., and 96 operational Listeria spp.). Microbial outcomes did not differ (P > 0.05) based on the overall number of recommended sanitary control methods used and the type of facility inspection. There was a greater content domain compliance overall in operational sanitation (P = 0.0005), sanitation (P = 0.0030), facility (P = 0.0397), and personal hygiene (P = 0.0033) than for segregation procedures regardless of the regulating body. Findings suggest that regardless of the regulating body, the quality of sanitary control measures used is more impactful for microbial control than simply the quantity implemented. Pathogen control may be obtained without implementing all of the sanitary control methods within the guidance documents.