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Papers by Alejandro Echeverry

Foods, Feb 18, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Meat and muscle biology, 2018

Meat and muscle biology, Apr 1, 2018

Salmonella continues to be a leading cause of morbidity due to foodborne illness in the United St... more Salmonella continues to be a leading cause of morbidity due to foodborne illness in the United States, accounting for 11% of the total annual foodborne illness cases (> 1 million). Pork is known to carry Salmonella, and it is critical that interventions be validated in simulated industry settings to demonstrate effective reductions of this pathogen. The purpose of this study was to determine the efficacy of various FSIS approved interventions on the reduction of Salmonella on postharvest chilled pork head meat.

Meat and muscle biology, 2018

To compare and characterize the antimicrobial resistance and multidrug resistance patterns of Sal... more To compare and characterize the antimicrobial resistance and multidrug resistance patterns of Salmonella isolates obtained from Honduras based on the source of isolation.

Meat and muscle biology, 2017

A substantial number of cattle are raised in Mexico and imported into the U.S., however due to la... more A substantial number of cattle are raised in Mexico and imported into the U.S., however due to lax regulations, protocols for use of antibiotics in animals are not always properly followed. The objective of this study was to determine and compare the antibiotic susceptibility profiles of Salmonella enterica recovered along the beef production chain in Southeastern Mexico.

Meat and muscle biology, Feb 1, 2019

Despite being the target of control efforts for many decades, Salmonella enterica continues to be... more Despite being the target of control efforts for many decades, Salmonella enterica continues to be linked with a large amount of foodborne illnesses and outbreaks worldwide. Over the years, Salmonella isolated from meat products have exhibited a high level of antibiotic resistance. In this study, a total of 351 Salmonella isolates, recovered from cattle fecal samples (n = 31), hides (n = 105), and beef carcasses (n = 215) from 3 abattoirs in Mexico were analyzed for antimicrobial susceptibility. Resistance to at least one antimicrobial drug was found in 205 (58.4%) isolates and 20 different resistance phenotypes were observed among this Salmonella isolates set. Resistance to tetracycline (40.2%) and nalidixic acid (21.1%) was most commonly observed. Additionally, the most common multidrug-resistant (MDR) phenotypes shared resistance to chloramphenicol, streptomycin, tetracycline, and trimethopin/sulfamethoxazole (11.3%), resistance to ampicillin, tetracycline, and trimethopin/ sulfamethoxazole (3.4%), and resistance to ampicillin, streptomycin, and tetracycline (2.5%). When it came to antimicrobial resistance phenotypes in each abattoir, we determined there was no statistical difference in the frequency of resistant vs. susceptible Salmonella isolates among the three abattoirs (P > 0.05). These data indicate that Salmonella isolates recovered from beef cattle in Mexico are commonly resistant to antimicrobials and often multiple antimicrobials. In Mexico, antimicrobial resistance, and in particular, multidrug-resistance, maybe of particular concern due to the much higher prevalence of Salmonella in retail beef. This may lead to the spread of resistance and to the reduction of antibiotic efficacy for the control of animal and human infections. Promoting control measures and inspection standards on imported animals and food products should be applied to avoid the spread of antibiotic resistance in various populations and among countries.

Journal of Food Protection, 2018

Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but... more Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but its time-temperature tables and humidity requirements were originally developed and validated only for Salmonella in roast, cooked, and corned beef. Appendix A however, is routinely applied to a much wider array of products than those examined in the original study. Furthermore the humidity requirements are limited in scope and difficult to apply to certain processes. Product-specific, time-temperature tables along with more flexible and robust humidity requirements are needed to improve validation of thermal processes Purpose: To determine the temperature-death times of Salmonella in high-fat frankfurter batter at four different temperatures and validate these findings using commercial product and cooking processes. Materials and methods: Mechanically-separated turkey, 50% lean pork trimmings, and all non-meat ingredients were chopped in a vertical cutter mixer, under vacuum, until a temperature of 12.7°C was reached. The batter was then inoculated with 8-log cfu/g Salmonella (5-strain mixture) and mixed for 1.5 minutes. D-value determination: One-g samples of inoculated batter were flattened into a thin film (0.5-1.0 mm thickness) in moistureimpermeable pouches and vacuum-packaged. Samples were heated at one of four temperatures (54.4°C, 60°C, 65.6°C, 71.1°C) in a water bath. Triplicate samples were removed at predetermined time points and immediately chilled to ≤4°C by immersion in an ice water bath. Samples were then enumerated for the survival of Salmonella using XLD agar with a thin layer overlay of nonselective media to enhance recovery of injured cells. D-values were calculated from the linear regression on log reduction of Salmonella versus time. This experiment was replicated three times. Validation: Inoculated batter was stuffed into size 28 cellulose casings and linked manually in 6-inch increments. Links were then transferred to a combination steam/convection oven and thermally processed following one of two cook schedules until an internal temperature of 71.1°C was achieved. The control cycle maintained a relative humidity ≥50% for half the duration of the cook cycle. The test cycle only applied steam during the final step of the process to investigate the efficacy of a surface lethality step. For both processes, triplicate links were removed when product internal temperature reached 54.4°C, 62.7°C, and 71.1°C. Casings were removed aseptically and 2.5 cm was removed from each end of the links. The central portion of each link was enumerated for the survival of Salmonella using the methods described above. This experiment was repeated twice. Results: D-values for 54.4°C, 60°C, 65.6°C, and 71.1°C were 20.48 ± 6.54, 1.74 ± 0.10, 0.26 ± 0.06, and 0.06 ± 0.01 minutes, respectively. The control cycle produced an average log reduction of-0.01 ± 0.04, 6.86 ± 0.11, and 6.86 ± 0.11 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved an average log reduction of 0.07 ± 0.11, 5.94 ± 1.30, and 6.91 ± 0.18 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved lethality comparable to that seen with the control cycle. Conclusion: Appendix A time-temperature recommendations are adequate for controlling Salmonella in high-fat, small diameter products. Wet-bulb time-temperature may be sufficient as a replacement for relative humidity requirements.

Food protection trends, 2017

This study was conducted to determine the impact of carcass anatomical location on the microbiolo... more This study was conducted to determine the impact of carcass anatomical location on the microbiological profile of beef trimmings. A total of 375 chuck (24-30% fat), heel (5-10% fat), shank (5-10% fat), and sparse lean (> 70% fat) trim samples representing several carcass locations were collected at a large beef fabrication facility in the Midwestern U.S. on five non-consecutive days (morning, midday, and evenings production shifts) during the fall/winter season of 2015/2016. For each sample, aerobic (AC), coliform (CC), and Escherichia coli (EC) counts were estimated using 3M™ Petrifilms. AC were significantly higher (P < 0.01) on chuck trimmings (2.00 ± 0.75 log 10 CFU/cm 2) than on heel, shank, or sparse lean trim (1.24 ± 0.74, 1.23 ± 0.83, and 1.43 ± 0.75 log 10 CFU/cm 2 , respectively). All CC and EC were under the limit of quantification (< 10 CFU/cm 2). Production shift had no effect on aerobic bacteria counts, and surface fat content (used as a proxy for carcass location) was a poor predictor of AC on beef trim. These results indicate that beef trimmings collected from different carcass locations with varying surface fat contents do not have significantly different microbiological profiles. The differences observed (0.57-0.77 log 10 CFU/cm 2) in AC may not be of practical significance for food safety and quality.

Meat and Muscle Biology, 2018

Meat Science, 2016

subjected to analysis of variance (ANOVA). Tukey´s multiple range test (p b 0.05) was conducted t... more subjected to analysis of variance (ANOVA). Tukey´s multiple range test (p b 0.05) was conducted to determine differences between means. Results: Samples obtained by treatment of 150 g/L of GlcN after 3 h of incubation showed antimicrobial activity; the percentage of inhibition by these samples increased overtime in GlcN and GlcN/ Fe 2 + samples from 6% to 29% and 10% to 50%, respectively. In particular, the sample GlcN/Fe 2 + incubated for 48 hours inhibited the bacterial growth by 50% (IC50) at a concentration of 5% (w/v) while the sample GlcN incubated for the same time did not show activity. These results might be attributed to the production of Maillard reaction compounds such as α-dicarbonyls. Indeed, GlcN/ Fe 2 + contained two major α-dicarbonyl compounds: glucosone and 3-deoxyglucosone. The amount of 3-deoxyglucosone found in our most effective treatment was 0.89 ± 0.01 g/L, which was close to the IC50 of the pure standard (1 g/L). Other α-dicarbonyls compounds such us glyoxal, methylglyoxal and diacetyl were identified at much more lower concentration. Conclusion: Non-enzymatically modified GlcN at a concentration of 5% inhibited the growth of thermo resistant E. coli AW 1.7 in vitro, which opens the possibility of using this amino-sugar as an antimicrobial compound directly in meat products. Compounds contributing to such inhibitory property are α-dicarbonyls. Hence, GlcN might be a valuable food ingredient for the meat processing industry.

Meat Science, 2015

surviving L. innocua cells were differentially enumerated by plating on modified Oxford's (MOX) a... more surviving L. innocua cells were differentially enumerated by plating on modified Oxford's (MOX) agar not containing antimicrobic supplement to allow repair and colony formation of sub-lethally injured L. innocua cells. Replicate-specific L. innocua reductions were calculated as log 10 CFU/cm 2 of control minus log 10 CFU/cm 2 of the enumerated survivors for each sanitizer-treated site. Least squares means of reductions were calculated with a α = 0.05, using the general linear model of SAS. Significant differences were determined using the PDIFF function (P b 0.05). Results: All three sanitizer treatments differed (P b 0.05) from each other with Cl producing the least reduction (1.46 log 10 CFU/cm 2) and WF the greatest reduction (2.83 log 10 CFU/cm 2). There was not an effect of sanitizer contact time on reductions of L. innocua observed; a significant (P b 0.05) site by treatment interaction was observed. Conclusion: The results of the study indicate that QAC sanitizers (600 ppm) applied by both WF and DF were more effective at reducing L. innocua, from residual turkey slurry film than a traditional Cl sanitizer (200 ppm) on unwashed slicer surfaces.

Journal of Food Science, 2008

ABSTRACT: Meals ready‐to‐eat (MRE) are self‐contained and flexible packages used by military per... more ABSTRACT: Meals ready‐to‐eat (MRE) are self‐contained and flexible packages used by military personnel while in the field to store food for an extended period of time; however, inclusion of white bread is not a common practice because of short shelf life stability and spoilage. The objective of this study was to determine mold inhibition and quality attributes over a 60‐d period after applying directional microwaves. Different bread loaves were used for quality and for microbiological experiments. For microbiological analysis, bread was exposed to 0‐, 5‐, 6‐, 7‐, 8‐, 9‐, and 10‐s directional microwave treatments after inoculation with a 3 strain cocktail of common bread mold, stored at 25 °C for 60 d, and monitored for mold growth. For quality analysis, bread was exposed to 0‐ and 10‐s treatments, stored at 25 °C, and moisture, water activity (aw), softness, and sensory analysis were analyzed on 0, 7, 14, 28, 45, and 60 d. There was no quantifiable mold present at day 0 when treate...

Journal of Food Protection, 2013

To determine the prevalence of Salmonella and Escherichia coli O157:H7 in cattle feedlots and the... more To determine the prevalence of Salmonella and Escherichia coli O157:H7 in cattle feedlots and the impact of subsequent contamination on carcasses in a Mexican Federal Inspection Type Standards harvest facility, 250 animals were tagged and sampled in each step of the slaughter process. Samples were taken from hides and fecal grabs, and composite samples were taken from three anatomical carcass sites (hindshank, foreshank, and inside round) during the slaughter process, at preevisceration (PE), prior to entering the hot box (PHB), and after 24 h of dry chilling (DC). Additionally, 250 fecal samples were collected from the feedlot (FL), holding pens (HP), and intestinal feces (IF), and water samples were taken from the HP area. E. coli O157:H7 and Salmonella detection were carried out with the BAX System, immunomagnetic separation, and conventional methods. Overall Salmonella prevalence was 52.5%. The highest prevalence (92.4%) was found on hides, followed by feces from the HP (91.0%),...

Journal of Food Protection, 2013

Mechanical tenderization improves the palatability of beef; however, it increases the risk of tra... more Mechanical tenderization improves the palatability of beef; however, it increases the risk of translocating pathogenic bacteria to the interior of beef cuts. This study investigated the efficacies of lactic acid spray (LA; 5%), storage, and cooking on the survivability of Escherichia coli O157:H7 in mechanically tenderized beef steaks managed under simulated industry conditions. Beef subprimals inoculated with either high (105 CFU/ml) or low (103 CFU/ml) levels of E. coli O157:H7 were treated (LA or control) and stored for 21 days prior to mechanical tenderization, steak portioning (2.54 cm), and additional storage for 7 days. Steaks were then cooked to an internal temperature of 55, 60, 65, 70, or 75°C. Samples were enumerated and analyzed using DNA-based methods. Treatment with LA immediately reduced E. coli O157:H7 on the lean and fat surfaces of high- and low-inoculum–treated subprimals by more than 1.0 log CFU/cm2 (P < 0.05). Storage for 21 days reduced surface populations o...

Meat Science, 2016

Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but... more Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but its time-temperature tables and humidity requirements were originally developed and validated only for Salmonella in roast, cooked, and corned beef. Appendix A however, is routinely applied to a much wider array of products than those examined in the original study. Furthermore the humidity requirements are limited in scope and difficult to apply to certain processes. Product-specific, time-temperature tables along with more flexible and robust humidity requirements are needed to improve validation of thermal processes Purpose: To determine the temperature-death times of Salmonella in high-fat frankfurter batter at four different temperatures and validate these findings using commercial product and cooking processes. Materials and methods: Mechanically-separated turkey, 50% lean pork trimmings, and all non-meat ingredients were chopped in a vertical cutter mixer, under vacuum, until a temperature of 12.7°C was reached. The batter was then inoculated with 8-log cfu/g Salmonella (5-strain mixture) and mixed for 1.5 minutes. D-value determination: One-g samples of inoculated batter were flattened into a thin film (0.5-1.0 mm thickness) in moistureimpermeable pouches and vacuum-packaged. Samples were heated at one of four temperatures (54.4°C, 60°C, 65.6°C, 71.1°C) in a water bath. Triplicate samples were removed at predetermined time points and immediately chilled to ≤4°C by immersion in an ice water bath. Samples were then enumerated for the survival of Salmonella using XLD agar with a thin layer overlay of nonselective media to enhance recovery of injured cells. D-values were calculated from the linear regression on log reduction of Salmonella versus time. This experiment was replicated three times. Validation: Inoculated batter was stuffed into size 28 cellulose casings and linked manually in 6-inch increments. Links were then transferred to a combination steam/convection oven and thermally processed following one of two cook schedules until an internal temperature of 71.1°C was achieved. The control cycle maintained a relative humidity ≥50% for half the duration of the cook cycle. The test cycle only applied steam during the final step of the process to investigate the efficacy of a surface lethality step. For both processes, triplicate links were removed when product internal temperature reached 54.4°C, 62.7°C, and 71.1°C. Casings were removed aseptically and 2.5 cm was removed from each end of the links. The central portion of each link was enumerated for the survival of Salmonella using the methods described above. This experiment was repeated twice. Results: D-values for 54.4°C, 60°C, 65.6°C, and 71.1°C were 20.48 ± 6.54, 1.74 ± 0.10, 0.26 ± 0.06, and 0.06 ± 0.01 minutes, respectively. The control cycle produced an average log reduction of-0.01 ± 0.04, 6.86 ± 0.11, and 6.86 ± 0.11 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved an average log reduction of 0.07 ± 0.11, 5.94 ± 1.30, and 6.91 ± 0.18 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved lethality comparable to that seen with the control cycle. Conclusion: Appendix A time-temperature recommendations are adequate for controlling Salmonella in high-fat, small diameter products. Wet-bulb time-temperature may be sufficient as a replacement for relative humidity requirements.

Foods

The objective of the study was to determine the impact of antimicrobial interventions and refrige... more The objective of the study was to determine the impact of antimicrobial interventions and refrigerated dark storage on the shelf-life of pork chops. Boneless pork loins (n = 36) were split and stored for 1, 14, 28, and 42 days at 2–4 °C after being treated with the following antimicrobials: water (WAT), Bovibrom 225 ppm (BB225), Bovibrom 500 ppm (BB500), Fit Fresh 3 ppm (FF3), or washing solution 750 ppm (WS750). After the end of dark storage, pork loins were further processed and sliced into chops, overwrapped in trays, and displayed for up to an additional 96 h in a retail case. Instrumental and visual color measurements as well as mesophilic and psychrotrophic aerobic bacteria, and lactic acid bacteria were measured. BB500 and FF3 performed better in inhibiting the growth of indicator bacteria under 6 logs; however, FF3 presented the best stability for color during storage. Principal component analysis clustered initial dark storage days with a* and chroma while % discoloration, ...

Food protection trends, 2019

Foods, Feb 18, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Meat and muscle biology, 2018

Meat and muscle biology, Apr 1, 2018

Salmonella continues to be a leading cause of morbidity due to foodborne illness in the United St... more Salmonella continues to be a leading cause of morbidity due to foodborne illness in the United States, accounting for 11% of the total annual foodborne illness cases (> 1 million). Pork is known to carry Salmonella, and it is critical that interventions be validated in simulated industry settings to demonstrate effective reductions of this pathogen. The purpose of this study was to determine the efficacy of various FSIS approved interventions on the reduction of Salmonella on postharvest chilled pork head meat.

Meat and muscle biology, 2018

To compare and characterize the antimicrobial resistance and multidrug resistance patterns of Sal... more To compare and characterize the antimicrobial resistance and multidrug resistance patterns of Salmonella isolates obtained from Honduras based on the source of isolation.

Meat and muscle biology, 2017

A substantial number of cattle are raised in Mexico and imported into the U.S., however due to la... more A substantial number of cattle are raised in Mexico and imported into the U.S., however due to lax regulations, protocols for use of antibiotics in animals are not always properly followed. The objective of this study was to determine and compare the antibiotic susceptibility profiles of Salmonella enterica recovered along the beef production chain in Southeastern Mexico.

Meat and muscle biology, Feb 1, 2019

Despite being the target of control efforts for many decades, Salmonella enterica continues to be... more Despite being the target of control efforts for many decades, Salmonella enterica continues to be linked with a large amount of foodborne illnesses and outbreaks worldwide. Over the years, Salmonella isolated from meat products have exhibited a high level of antibiotic resistance. In this study, a total of 351 Salmonella isolates, recovered from cattle fecal samples (n = 31), hides (n = 105), and beef carcasses (n = 215) from 3 abattoirs in Mexico were analyzed for antimicrobial susceptibility. Resistance to at least one antimicrobial drug was found in 205 (58.4%) isolates and 20 different resistance phenotypes were observed among this Salmonella isolates set. Resistance to tetracycline (40.2%) and nalidixic acid (21.1%) was most commonly observed. Additionally, the most common multidrug-resistant (MDR) phenotypes shared resistance to chloramphenicol, streptomycin, tetracycline, and trimethopin/sulfamethoxazole (11.3%), resistance to ampicillin, tetracycline, and trimethopin/ sulfamethoxazole (3.4%), and resistance to ampicillin, streptomycin, and tetracycline (2.5%). When it came to antimicrobial resistance phenotypes in each abattoir, we determined there was no statistical difference in the frequency of resistant vs. susceptible Salmonella isolates among the three abattoirs (P > 0.05). These data indicate that Salmonella isolates recovered from beef cattle in Mexico are commonly resistant to antimicrobials and often multiple antimicrobials. In Mexico, antimicrobial resistance, and in particular, multidrug-resistance, maybe of particular concern due to the much higher prevalence of Salmonella in retail beef. This may lead to the spread of resistance and to the reduction of antibiotic efficacy for the control of animal and human infections. Promoting control measures and inspection standards on imported animals and food products should be applied to avoid the spread of antibiotic resistance in various populations and among countries.

Journal of Food Protection, 2018

Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but... more Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but its time-temperature tables and humidity requirements were originally developed and validated only for Salmonella in roast, cooked, and corned beef. Appendix A however, is routinely applied to a much wider array of products than those examined in the original study. Furthermore the humidity requirements are limited in scope and difficult to apply to certain processes. Product-specific, time-temperature tables along with more flexible and robust humidity requirements are needed to improve validation of thermal processes Purpose: To determine the temperature-death times of Salmonella in high-fat frankfurter batter at four different temperatures and validate these findings using commercial product and cooking processes. Materials and methods: Mechanically-separated turkey, 50% lean pork trimmings, and all non-meat ingredients were chopped in a vertical cutter mixer, under vacuum, until a temperature of 12.7°C was reached. The batter was then inoculated with 8-log cfu/g Salmonella (5-strain mixture) and mixed for 1.5 minutes. D-value determination: One-g samples of inoculated batter were flattened into a thin film (0.5-1.0 mm thickness) in moistureimpermeable pouches and vacuum-packaged. Samples were heated at one of four temperatures (54.4°C, 60°C, 65.6°C, 71.1°C) in a water bath. Triplicate samples were removed at predetermined time points and immediately chilled to ≤4°C by immersion in an ice water bath. Samples were then enumerated for the survival of Salmonella using XLD agar with a thin layer overlay of nonselective media to enhance recovery of injured cells. D-values were calculated from the linear regression on log reduction of Salmonella versus time. This experiment was replicated three times. Validation: Inoculated batter was stuffed into size 28 cellulose casings and linked manually in 6-inch increments. Links were then transferred to a combination steam/convection oven and thermally processed following one of two cook schedules until an internal temperature of 71.1°C was achieved. The control cycle maintained a relative humidity ≥50% for half the duration of the cook cycle. The test cycle only applied steam during the final step of the process to investigate the efficacy of a surface lethality step. For both processes, triplicate links were removed when product internal temperature reached 54.4°C, 62.7°C, and 71.1°C. Casings were removed aseptically and 2.5 cm was removed from each end of the links. The central portion of each link was enumerated for the survival of Salmonella using the methods described above. This experiment was repeated twice. Results: D-values for 54.4°C, 60°C, 65.6°C, and 71.1°C were 20.48 ± 6.54, 1.74 ± 0.10, 0.26 ± 0.06, and 0.06 ± 0.01 minutes, respectively. The control cycle produced an average log reduction of-0.01 ± 0.04, 6.86 ± 0.11, and 6.86 ± 0.11 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved an average log reduction of 0.07 ± 0.11, 5.94 ± 1.30, and 6.91 ± 0.18 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved lethality comparable to that seen with the control cycle. Conclusion: Appendix A time-temperature recommendations are adequate for controlling Salmonella in high-fat, small diameter products. Wet-bulb time-temperature may be sufficient as a replacement for relative humidity requirements.

Food protection trends, 2017

This study was conducted to determine the impact of carcass anatomical location on the microbiolo... more This study was conducted to determine the impact of carcass anatomical location on the microbiological profile of beef trimmings. A total of 375 chuck (24-30% fat), heel (5-10% fat), shank (5-10% fat), and sparse lean (> 70% fat) trim samples representing several carcass locations were collected at a large beef fabrication facility in the Midwestern U.S. on five non-consecutive days (morning, midday, and evenings production shifts) during the fall/winter season of 2015/2016. For each sample, aerobic (AC), coliform (CC), and Escherichia coli (EC) counts were estimated using 3M™ Petrifilms. AC were significantly higher (P < 0.01) on chuck trimmings (2.00 ± 0.75 log 10 CFU/cm 2) than on heel, shank, or sparse lean trim (1.24 ± 0.74, 1.23 ± 0.83, and 1.43 ± 0.75 log 10 CFU/cm 2 , respectively). All CC and EC were under the limit of quantification (< 10 CFU/cm 2). Production shift had no effect on aerobic bacteria counts, and surface fat content (used as a proxy for carcass location) was a poor predictor of AC on beef trim. These results indicate that beef trimmings collected from different carcass locations with varying surface fat contents do not have significantly different microbiological profiles. The differences observed (0.57-0.77 log 10 CFU/cm 2) in AC may not be of practical significance for food safety and quality.

Meat and Muscle Biology, 2018

Meat Science, 2016

subjected to analysis of variance (ANOVA). Tukey´s multiple range test (p b 0.05) was conducted t... more subjected to analysis of variance (ANOVA). Tukey´s multiple range test (p b 0.05) was conducted to determine differences between means. Results: Samples obtained by treatment of 150 g/L of GlcN after 3 h of incubation showed antimicrobial activity; the percentage of inhibition by these samples increased overtime in GlcN and GlcN/ Fe 2 + samples from 6% to 29% and 10% to 50%, respectively. In particular, the sample GlcN/Fe 2 + incubated for 48 hours inhibited the bacterial growth by 50% (IC50) at a concentration of 5% (w/v) while the sample GlcN incubated for the same time did not show activity. These results might be attributed to the production of Maillard reaction compounds such as α-dicarbonyls. Indeed, GlcN/ Fe 2 + contained two major α-dicarbonyl compounds: glucosone and 3-deoxyglucosone. The amount of 3-deoxyglucosone found in our most effective treatment was 0.89 ± 0.01 g/L, which was close to the IC50 of the pure standard (1 g/L). Other α-dicarbonyls compounds such us glyoxal, methylglyoxal and diacetyl were identified at much more lower concentration. Conclusion: Non-enzymatically modified GlcN at a concentration of 5% inhibited the growth of thermo resistant E. coli AW 1.7 in vitro, which opens the possibility of using this amino-sugar as an antimicrobial compound directly in meat products. Compounds contributing to such inhibitory property are α-dicarbonyls. Hence, GlcN might be a valuable food ingredient for the meat processing industry.

Meat Science, 2015

surviving L. innocua cells were differentially enumerated by plating on modified Oxford's (MOX) a... more surviving L. innocua cells were differentially enumerated by plating on modified Oxford's (MOX) agar not containing antimicrobic supplement to allow repair and colony formation of sub-lethally injured L. innocua cells. Replicate-specific L. innocua reductions were calculated as log 10 CFU/cm 2 of control minus log 10 CFU/cm 2 of the enumerated survivors for each sanitizer-treated site. Least squares means of reductions were calculated with a α = 0.05, using the general linear model of SAS. Significant differences were determined using the PDIFF function (P b 0.05). Results: All three sanitizer treatments differed (P b 0.05) from each other with Cl producing the least reduction (1.46 log 10 CFU/cm 2) and WF the greatest reduction (2.83 log 10 CFU/cm 2). There was not an effect of sanitizer contact time on reductions of L. innocua observed; a significant (P b 0.05) site by treatment interaction was observed. Conclusion: The results of the study indicate that QAC sanitizers (600 ppm) applied by both WF and DF were more effective at reducing L. innocua, from residual turkey slurry film than a traditional Cl sanitizer (200 ppm) on unwashed slicer surfaces.

Journal of Food Science, 2008

ABSTRACT: Meals ready‐to‐eat (MRE) are self‐contained and flexible packages used by military per... more ABSTRACT: Meals ready‐to‐eat (MRE) are self‐contained and flexible packages used by military personnel while in the field to store food for an extended period of time; however, inclusion of white bread is not a common practice because of short shelf life stability and spoilage. The objective of this study was to determine mold inhibition and quality attributes over a 60‐d period after applying directional microwaves. Different bread loaves were used for quality and for microbiological experiments. For microbiological analysis, bread was exposed to 0‐, 5‐, 6‐, 7‐, 8‐, 9‐, and 10‐s directional microwave treatments after inoculation with a 3 strain cocktail of common bread mold, stored at 25 °C for 60 d, and monitored for mold growth. For quality analysis, bread was exposed to 0‐ and 10‐s treatments, stored at 25 °C, and moisture, water activity (aw), softness, and sensory analysis were analyzed on 0, 7, 14, 28, 45, and 60 d. There was no quantifiable mold present at day 0 when treate...

Journal of Food Protection, 2013

To determine the prevalence of Salmonella and Escherichia coli O157:H7 in cattle feedlots and the... more To determine the prevalence of Salmonella and Escherichia coli O157:H7 in cattle feedlots and the impact of subsequent contamination on carcasses in a Mexican Federal Inspection Type Standards harvest facility, 250 animals were tagged and sampled in each step of the slaughter process. Samples were taken from hides and fecal grabs, and composite samples were taken from three anatomical carcass sites (hindshank, foreshank, and inside round) during the slaughter process, at preevisceration (PE), prior to entering the hot box (PHB), and after 24 h of dry chilling (DC). Additionally, 250 fecal samples were collected from the feedlot (FL), holding pens (HP), and intestinal feces (IF), and water samples were taken from the HP area. E. coli O157:H7 and Salmonella detection were carried out with the BAX System, immunomagnetic separation, and conventional methods. Overall Salmonella prevalence was 52.5%. The highest prevalence (92.4%) was found on hides, followed by feces from the HP (91.0%),...

Journal of Food Protection, 2013

Mechanical tenderization improves the palatability of beef; however, it increases the risk of tra... more Mechanical tenderization improves the palatability of beef; however, it increases the risk of translocating pathogenic bacteria to the interior of beef cuts. This study investigated the efficacies of lactic acid spray (LA; 5%), storage, and cooking on the survivability of Escherichia coli O157:H7 in mechanically tenderized beef steaks managed under simulated industry conditions. Beef subprimals inoculated with either high (105 CFU/ml) or low (103 CFU/ml) levels of E. coli O157:H7 were treated (LA or control) and stored for 21 days prior to mechanical tenderization, steak portioning (2.54 cm), and additional storage for 7 days. Steaks were then cooked to an internal temperature of 55, 60, 65, 70, or 75°C. Samples were enumerated and analyzed using DNA-based methods. Treatment with LA immediately reduced E. coli O157:H7 on the lean and fat surfaces of high- and low-inoculum–treated subprimals by more than 1.0 log CFU/cm2 (P < 0.05). Storage for 21 days reduced surface populations o...

Meat Science, 2016

Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but... more Objectives: USDA, FSIS Appendix A is widely used as validation support for thermal processes, but its time-temperature tables and humidity requirements were originally developed and validated only for Salmonella in roast, cooked, and corned beef. Appendix A however, is routinely applied to a much wider array of products than those examined in the original study. Furthermore the humidity requirements are limited in scope and difficult to apply to certain processes. Product-specific, time-temperature tables along with more flexible and robust humidity requirements are needed to improve validation of thermal processes Purpose: To determine the temperature-death times of Salmonella in high-fat frankfurter batter at four different temperatures and validate these findings using commercial product and cooking processes. Materials and methods: Mechanically-separated turkey, 50% lean pork trimmings, and all non-meat ingredients were chopped in a vertical cutter mixer, under vacuum, until a temperature of 12.7°C was reached. The batter was then inoculated with 8-log cfu/g Salmonella (5-strain mixture) and mixed for 1.5 minutes. D-value determination: One-g samples of inoculated batter were flattened into a thin film (0.5-1.0 mm thickness) in moistureimpermeable pouches and vacuum-packaged. Samples were heated at one of four temperatures (54.4°C, 60°C, 65.6°C, 71.1°C) in a water bath. Triplicate samples were removed at predetermined time points and immediately chilled to ≤4°C by immersion in an ice water bath. Samples were then enumerated for the survival of Salmonella using XLD agar with a thin layer overlay of nonselective media to enhance recovery of injured cells. D-values were calculated from the linear regression on log reduction of Salmonella versus time. This experiment was replicated three times. Validation: Inoculated batter was stuffed into size 28 cellulose casings and linked manually in 6-inch increments. Links were then transferred to a combination steam/convection oven and thermally processed following one of two cook schedules until an internal temperature of 71.1°C was achieved. The control cycle maintained a relative humidity ≥50% for half the duration of the cook cycle. The test cycle only applied steam during the final step of the process to investigate the efficacy of a surface lethality step. For both processes, triplicate links were removed when product internal temperature reached 54.4°C, 62.7°C, and 71.1°C. Casings were removed aseptically and 2.5 cm was removed from each end of the links. The central portion of each link was enumerated for the survival of Salmonella using the methods described above. This experiment was repeated twice. Results: D-values for 54.4°C, 60°C, 65.6°C, and 71.1°C were 20.48 ± 6.54, 1.74 ± 0.10, 0.26 ± 0.06, and 0.06 ± 0.01 minutes, respectively. The control cycle produced an average log reduction of-0.01 ± 0.04, 6.86 ± 0.11, and 6.86 ± 0.11 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved an average log reduction of 0.07 ± 0.11, 5.94 ± 1.30, and 6.91 ± 0.18 for the 54.4°C, 62.7°C, and 71.1°C target temperatures, respectively. The test cycle achieved lethality comparable to that seen with the control cycle. Conclusion: Appendix A time-temperature recommendations are adequate for controlling Salmonella in high-fat, small diameter products. Wet-bulb time-temperature may be sufficient as a replacement for relative humidity requirements.

Foods

The objective of the study was to determine the impact of antimicrobial interventions and refrige... more The objective of the study was to determine the impact of antimicrobial interventions and refrigerated dark storage on the shelf-life of pork chops. Boneless pork loins (n = 36) were split and stored for 1, 14, 28, and 42 days at 2–4 °C after being treated with the following antimicrobials: water (WAT), Bovibrom 225 ppm (BB225), Bovibrom 500 ppm (BB500), Fit Fresh 3 ppm (FF3), or washing solution 750 ppm (WS750). After the end of dark storage, pork loins were further processed and sliced into chops, overwrapped in trays, and displayed for up to an additional 96 h in a retail case. Instrumental and visual color measurements as well as mesophilic and psychrotrophic aerobic bacteria, and lactic acid bacteria were measured. BB500 and FF3 performed better in inhibiting the growth of indicator bacteria under 6 logs; however, FF3 presented the best stability for color during storage. Principal component analysis clustered initial dark storage days with a* and chroma while % discoloration, ...

Food protection trends, 2019