Browsing by Author "Casas, Diego E. (TTU)"

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Bio-Mapping Indicators and Pathogen Loads in a Commercial Broiler Processing Facility Operating with High and Low Antimicrobial Intervention Levels
(2022) De Villena, Juan F. (TTU); Vargas, David A. (TTU); López, Rossy Bueno (TTU); Chávez-Velado, Daniela R. (TTU); Casas, Diego E. (TTU); Jiménez, Reagan L. (TTU); Sanchez-Plata, Marcos X. (TTU)
The poultry industry in the United States has traditionally implemented non-chemical and chemical interventions against Salmonella spp. and Campylobacter spp. on the basis of experience and word-of-mouth information shared among poultry processors. The effects of individual interventions have been assessed with microbiological testing methods for Salmonella spp. and Campylobacter spp. prevalence as well as quantification of indicator organisms, such as aerobic plate counts (APC), to demonstrate efficacy. The current study evaluated the loads of both indicators and pathogens in a commercial chicken processing facility, comparing the “normal chemical”, with all chemical interventions turned-on, at typical chemical concentrations set by the processing plant versus low-chemical process (“reduced chemical”), where all interventions were turned off or reduced to the minimum concentrations considered in the facility’s HACCP system. Enumeration and prevalence of Salmonella spp. and Campylobacter spp. as well as indicator organisms (APC and Enterobacteriaceae— EB) enumeration were evaluated to compare both treatments throughout a 25-month sampling period. Ten locations were selected in the current bio-mapping study, including live receiving, rehanger, post eviscerator, post cropper, post neck breaker, post IOBW #1, post IOBW #2, prechilling, post chilling, and parts (wings). Statistical process control parameters for each location and processing schemes were developed for each pathogen and indicator evaluated. Despite demonstrating significant statistical differences between the normal and naked processes in Salmonella spp. counts (“normal” significantly lower counts than the “reduced” at each location except for post-eviscerator and post-cropper locations), the prevalence of Salmonella spp. after chilling is comparable on both treatments (~10%), whereas for Campylobacter spp. counts, only at the parts’ location was there significant statistical difference between the “normal chemical” and the “reduced chemical”. Therefore, not all chemical intervention locations show an overall impact on Salmonella spp. or Campylobacter spp., and certain interventions can be turned off to achieve the same or better microbial performance if strategic intervention locations are enhanced.
Biomapping of microbial indicators on beef subprimals subjected to spray or dry chilling over prolonged refrigerated storage
(2021) Casas, Diego E. (TTU); Manishimwe, Rosine (TTU); Forgey, Savannah J. (TTU); Hanlon, Keelyn E. (TTU); Miller, Markus F. (TTU); Brashears, Mindy M. (TTU); Sanchez-Plata, Marcos X. (TTU)
As the global meat market moves to never frozen alternatives, meat processors seek opportunities for increasing the shelf life of fresh meats by combinations of proper cold chain management, barrier technologies, and antimicrobial interventions. The objective of this study was to determine the impact of spray and dry chilling combined with hot water carcass treatments on the levels of microbial indicator organisms during the long-term refrigerated storage of beef cuts. Samples were taken using EZ-Reach™ sponge samplers with 25 mL buffered peptone water over a 100 cm2 area of the striploin. Sample collection was conducted before the hot carcass wash, after wash, and after the 24 h carcass chilling. Chilled striploins were cut into four sections, individually vacuum packaged, and stored to be sampled at 0, 45, 70, and 135 days (n = 200) of refrigerated storage and distribution. Aerobic plate counts, enterobacteria, Escherichia coli, coliforms, and psychrotroph counts were evaluated for each sample. Not enough evidence (p > 0.05) was found indicating the hot water wash intervention reduced bacterial concentration on the carcass surface. E. coli was below detection limits (<0.25 CFU/cm2) in most of the samples taken. No significant difference (p > 0.05) was found between coliform counts throughout the sampling dates. Feed type did not seem to influence the (p > 0.25) microbial load of the treatments. Even though no immediate effect was seen when comparing spray or dry chilling of the samples at day 0, as the product aged, a significantly lower (p < 0.05) concentration of aerobic and psychrotrophic organisms in dry-chilled samples could be observed when compared to their spray-chilled counterparts. Data collected can be used to select alternative chilling systems to maximize shelf life in vacuum packaged beef kept over prolonged storage periods.
Data-Mining Poultry Processing Bio-Mapping Counts of Pathogens and Indicator Organisms for Food Safety Management Decision Making
(2023) Vargas, David A. (TTU); De Villena, Juan F. (TTU); Larios, Valeria (TTU); Bueno López, Rossy (TTU); Chávez-Velado, Daniela R. (TTU); Casas, Diego E. (TTU); Jiménez, Reagan L. (TTU); Blandon, Sabrina E. (TTU); Sanchez-Plata, Marcos X. (TTU)
Bio-mapping studies play an important role, as the data collected can be managed and analyzed in multiple ways to look at process trends, find explanations about the effect of process changes, activate a root cause analysis for events, and even compile performance data to demonstrate to inspection authorities or auditors the effect of certain decisions made on a daily basis and their effects over time in commercial settings not only from the food safety perspective but also from the production side. This study presents an alternative analysis of bio-mapping data collected throughout several months in a commercial poultry processing operation as described in the article “Bio-Mapping Indicators and Pathogen Loads in a Commercial Broiler Processing Facility Operating with High and Low Antimicrobial Interventions”. The conducted analysis identifies the processing shift effect on microbial loads, attempts to find correlation between microbial indicators data and pathogens loads, and identifies novel visualization approaches and conducts distribution analysis for microbial indicators and pathogens in a commercial poultry processing facility. From the data analyzed, a greater number of locations were statistically different between shifts under reduced levels of chemical interventions with higher means at the second shift for both indicators and pathogens levels. Minimal to negligible correlation was found when comparing aerobic counts and Enterobacteriaceae counts with Salmonella levels, with significant variability between sampling locations. Distribution analysis and visualization as a bio-map of the process resulted in a clear bimodality in reduced chemical conditions for multiple locations mostly explained by shift effect. The development and use of bio-mapping data, including proper data visualization, improves the tools needed for ongoing decision making in food safety systems.
Efficacy of Common Antimicrobial Interventions at and above Regulatory Allowable Pick-Up Levels on Pathogen Reduction
(2023) Blandon, Sabrina E. (TTU); Vargas, David A. (TTU); Casas, Diego E. (TTU); Sarasty, Oscar (TTU); Woerner, Dale R. (TTU); Echeverry, Alejandro (TTU); Miller, Markus F. (TTU); Carpio, Carlos E. (TTU); Sanchez-Plata, Marcos X. (TTU); Legako, Jerrad F. (TTU)
The objective of this study was to evaluate the food safety efficacy of common antimicrobial interventions at and above required uptake levels for processing aids on the reduction of Shiga-toxin producing E. coli (STEC) and Salmonella spp. through spray and dip applications. Beef trim was inoculated with specific isolates of STEC or Salmonella strains. Trim was intervened with peracetic or lactic acid through spray or dip application. Meat rinses were serially diluted and plated following the drop dilution method; an enumerable range of 2–30 colonies was used to report results before log transformation. The combination of all treatments exhibits an average reduction rate of 0.16 LogCFU/g for STEC and Salmonella spp., suggesting that for every 1% increase in uptake there is an increase of 0.16 LogCFU/g of reduction rate. There is a statistical significance in the reduction rate of Shiga-toxin producing Escherichia coli in relation to the uptake percentage (p < 0.01). The addition of explanatory variables increases the R2 of the regression for STEC, where all the additional explanatory variables are statistically significant for reduction (p < 0.01). The addition of explanatory variables increases the R2 of the regression for Salmonella spp., but only trim type is statistically significant for reduction rate (p < 0.01). An increase in uptake percentages showed a significant increase in reduction rate of pathogens on beef trimmings.
In-Plant Intervention Validation of a Novel Ozone Generation Technology (Bio-Safe) Compared to Lactic Acid in Variety Meats
(2021) Vargas, David A. (TTU); Casas, Diego E. (TTU); Chávez-Velado, Daniela R. (TTU); Jiménez, Reagan L. (TTU); Betancourt-Barszcz, Gabriela K. (TTU); Randazzo, Emile; Lynn, Dan; Echeverry, Alejandro (TTU); Brashears, Mindy M. (TTU); Sánchez-Plata, Marcos X. (TTU); Miller, Markus F. (TTU)
The objective of this experiment was to compare the antimicrobial efficacy of an aqueous ozone intervention and a lactic acid solution on natural microbiota of variety meats in a commercial beef processing plant. EZ-Reach™ swabs were used to collect 100 cm2 area samples before and after ozone and lactic acid intervention application for three different offals (head, heart, and liver). Each repetition included 54 samples per variety meat and antimicrobial for a total of 162 samples per repetition. Enumeration of total aerobic bacteria (APC) and Escherichia coli (EC) was performed on each sample. Microbial counts for both microorganisms evaluated were significantly reduced (p < 0.001) after lactic acid immersion (2–5%) and ozone intervention for all variety meats, with the exception of ozone intervention in EC counts of the heart samples. APC after lactic acid intervention was reduced on average by 1.73, 1.66, and 1.50 Log CFU/sample in the head, heart, and liver, respectively, while after ozone intervention, counts were reduced on average by 1.66, 0.52, and 1.20 Log CFU/sample. EC counts after lactic acid intervention were reduced on average by 0.96, 0.79, and 1.00 Log CFU/sample in the head, heart, and liver, respectively, while after ozone intervention, counts were reduced on average by 0.75, 0.62, and 1.25 Log CFU/sample. The aqueous ozone antimicrobial scheme proved to be a promising intervention for the in-plant reduction of indicator levels in variety meats, specifically heads, hearts, and livers.
In-plant validation of novel on-site ozone generation technology (Bio-safe) compared to lactic acid beef carcasses and trim using natural microbiota and salmonella and e. coli o157:H7 surrogate enumeration
(2021) Casas, Diego E. (TTU); Vargas, David A. (TTU); Randazzo, Emile; Lynn, Dan; Echeverry, Alejandro (TTU); Brashears, Mindy M. (TTU); Sanchez-Plata, Marcos X. (TTU); Miller, Markus F. (TTU)
The purpose of this study was to evaluate the antimicrobial efficacy of an aqueous ozone (Bio-Safe) treatment and lactic acid solutions on natural microbiota and E. coli O157:H7 and Salmonella surrogates on beef carcasses and trim in a commercial beef processing plant. For every repetition, 40 carcass and 40 trim swabs (500 cm2 ) were collected. Samples were taken using EZ-Reach™ swabs, and plated into aerobic plate count (APC), coliform, and E. coli Petrifilm™ for enumeration. In addition, a five-strain cocktail (MP-26) of E. coli surrogates was inoculated onto trim. For every trim surrogate repetition, 30 trim pieces were sampled after attachment and after ozone intervention. Samples were diluted and counts were determined using the TEMPO® system for E. coli enumeration. Ozone and lactic acid interventions significantly reduced (p < 0.003) bacterial counts in carcasses and trim samples. Moreover, lactic acid further reduced APC and coliforms in trim samples compared to ozone intervention (p < 0.009). In the surrogate trials, ozone significantly reduced (p < 0.001) surrogate concentration. Historical data from the plant revealed a reduction (p < 0.001) of presumptive E. coli O157:H7 in trim after a full year of ozone intervention implementation. The novel technology for ozone generation and application as an antimicrobial can become an alternative option that may also act synergistically with existing interventions, minimizing the risk of pathogens such as Salmonella and E. coli O157:H7.
Modernization Data Analysis and Visualization for Food Safety Research Outcomes
(2024) Vargas, David A. (TTU); Bueno López, Rossy (TTU); Casas, Diego E. (TTU); Osorio-Doblado, Andrea M.; Rodríguez, Karla M. (TTU); Vargas, Nathaly; Gragg, Sara E.; Brashears, Mindy M. (TTU); Miller, Markus F. (TTU); Sanchez-Plata, Marcos X. (TTU)
Appropriate data collection and using reliable and accurate procedures are the first steps in conducting an experiment that will provide trustworthy outcomes. It is key to perform an assertive statistical analysis and data visualization for a correct interpretation and communication of results. A clear statistical summary and presentation of the data is critical for the reader to easily process and comprehend experimental results. Nowadays, there are a series of different tools to perform proper statistical analysis and create elaborate graphs that will help readers to understand the data, identify trends, detect outliers, evaluate statistical outputs, etc. However, researchers that are beginning to navigate experiments do not frequently encounter a guide that can provide basic principal concepts to begin their statistical analysis and data presentation. Therefore, the objective of this article is to provide a guide or manual to analyze and presents results focused on different types of common food safety experiments, including method comparisons, intervention studies, pathogen presence experiments, bio-mapping, statistical process control, and shelf life experiments. This review will provide information about data visualization options and statistical analysis approaches for different food safety experiments. In addition, basic concepts about descriptive statistics and possible solutions for issues related to microbiological measurements will be discussed.
Quantitative Bio-Mapping of Salmonella and Indicator Organisms at Different Stages in a Commercial Pork Processing Facility
(2022) Bueno López, Rossy (TTU); Vargas, David A. (TTU); Jimenez, Reagan L. (TTU); Casas, Diego E. (TTU); Miller, Markus F. (TTU); Brashears, Mindy M. (TTU); Sanchez-Plata, Marcos X. (TTU)
The purpose of this study was to develop a quantitative baseline of indicator organisms and Salmonella by bio-mapping throughout the processing chain from harvest to final product stages within a commercial conventional design pork processing establishment. Swab samples were taken on the harvest floor at different processing steps, gambrel table, after polisher, before final rinse, after the final rinse, post snap chill, and after peroxyacetic acid (PAA) application, while 2-pound product samples were collected for trim and ground samples. The samples were subjected to analysis for indicator microorganism enumeration, Aerobic Count (AC), Enterobacteriaceae (EB), and generic Escherichia coli (EC), with the BioMérieux TEMPO®. Salmonella prevalence and enumeration was evaluated using the BAX® System Real-Time Salmonella and the SalQuant™ methodology. Microbial counts were converted to Log Colony-forming units (CFU) on a per mL, per g or per sample basis, presented as LogCFU/mL, LogCFU/g and LogCFU/sample, prior to statistical analysis. All indicator microorganisms were significantly reduced at the harvest floor (p-value < 0.001), from gambrel table to after PAA cabinet location. The reduction at harvest was 2.27, 2.46 and 2.24 LogCFU/mL for AC, EB and EC, respectively. Trim sample values fluctuated based on cut, with the highest average AC count found at neck trim (2.83 LogCFU/g). Further process samples showed the highest AC count in sausage with a mean of 5.28 LogCFU/g. EB counts in sausage (3.19 LogCFU/g) showed an evident increase, compared to the reduction observed at the end of harvest and throughout trim processing. EC counts showed a similar trend to EB counts with the highest value found in sausage links (1.60 LogCFU/g). Statistical microbial process control (SPC) parameters were also developed for each of the indicator microorganisms, using the overall mean count ((Formula presented.)), the Lower control limit (LCL) and Upper control limit (UCL) at each sampling location. For Salmonella prevalence, a total of 125/650 samples were found positive (19%). From those positive samples, 47 samples (38%) were suitable for enumeration using the BAX® System SalQuant™, the majority detected at the gambrel table location. From those enumerable samples, 60% were estimated to be between 0.97 and 1.97 LogCFU/sample, while the rest (40%) were higher within the 2.00–4.02 LogCFU/sample range. This study provides evidence for the application of indicator and pathogen quantification methodologies for food safety management in commercial pork processing operations.