Beef Processing Research Articles

Effects of Finishing Diet and Packaging on Longissimus Dorsi Color

ObjectivesMeat color is extremely influential in purchasing decisions as consumers associate a bright-red color with freshness. The type of finishing diet can influence beef color. Previous studies have shown that grass-finished cattle have darker muscle color than grain-finished cattle. With the use of modified atmospheric packaging (MAP), beef purveyors are able to vary the gas compositions within a package and enhance beef color. However, limited studies have determined the effects of modified atmospheric packaging on grass-finished beef color. The objective of this study was to determine how finishing diet and packaging type affects the color of the longissimus dorsi (LD) muscle.Materials and MethodsDuring the stocker period, all of the cattle were on a forage diet. Cattle were then randomly assigned to either a conventional grain-based diet or an alfalfa pasture diet for finishing. Both conventionally and pasture-finished cattle were fed for 91 d. Cattle were slaughtered on the same day at a commercial beef processing facility under normal conditions and chilled for approximately 30 h. After grading, one strip loin from each carcass was collected and transported to Oklahoma State University. At 11 d postmortem, one steak (n = 60) from each strip loin was vacuum packaged and randomly assigned to display. Those steaks were then randomly assigned to PVC, HiOx-MAP (80% oxygen and 20% carbon dioxide), or CO-MAP (0.4% carbon monoxide, 69.5% nitrogen, and 30% carbon dioxide) packaging and were displayed under retail conditions for 5 d. Muscle darkening (MD), muscle color (MC), and surface discoloration (SD) were all analyzed by a trained panel (n = 6). MD was evaluated only on d 0 and MC and SD were scored once every 24 h for 0, 1, 2, 3, and 4 d. Lipid oxidation was measured by thiobarbituric acid reactive substances (TBARS) assay on d 4. Data were analyzed using the Mixed Procedure of SAS.ResultsThere was a significant display day by finishing diet by packaging interaction (P < 0.05) for muscle color and surface discoloration. There was also a significant finishing diet by packaging interaction (P < 0.05) for muscle darkening. Steaks packaged in HiOx-MAP remained the most stable in color and the brightest cherry-red colored throughout display time (P < 0.05) compared with other packaging types. PVC was the most discolored (P < 0.05) on d 3 and 4 when compared to HiOx-MAP and CO-MAP with the grain-finished PVC packaged steaks showing the most discoloration on d 4. Pasture-finished steaks packaged in CO-MAP displayed the darkest colored muscle (P < 0.05) on d 0. Steaks packaged in PVC had a higher amount of lipid oxidation (P < 0.05) compared with other packaging types.ConclusionThese results indicate that HiOx-MAP more effectively maintains the desired beef color of bright cherry-red for pasture-finished beef. The results also indicate that the use of appropriate packaging type can minimize the losses due to discoloration of steaks from either grain or grass-finished beef.

Fluctuations in the Microbial Community and the Volatile Organic Acids Created During Aerobic Storage of Ground Beef

ObjectivesDegradation due to microbial and chemical mechanisms occurs throughout the storage life of ground beef. These pathways are intertwined and the microbial community and the volatile organic acids (VOCs) that evolve in ground beef are dynamic. Evaluation of microbial growth using traditional culture-dependent techniques can be misleading due to the presence of unculturable organisms. Therefore, utilizing culture-independent techniques allows for a more thorough understanding of the microbial community within a meat matrix during storage life. The objective of this study was to employ 16s rRNA amplicon sequencing and VOC identification using GC–MS to explore diversity and changes of the microbial community and VOC production during shelf-life of ground beef.Materials and MethodsFinely ground beef (80/20) was procured from beef processing facilities in the West (one lot) and Midwest (two lots). The lots were separated into three physically separate replicates. Ground beef lots were transported in chub packaging to Colorado State University (Fort Collins, CO), and the chubs were stored in the dark at 2°C for either 16/17 d or 23/24 d. After dark storage, chubs were reground, and 454 g fluff-packs were placed on polystyrene trays before overwrapping with polyvinyl chloride film. The trays were placed in retail display cases maintained at 2–4°C for 5 d. Samples were collected every day of retail display for evaluation of the microbial community and VOC development. Following standardized extraction, 16S rRNA amplicon sequencing was used to explore microbial communities. Sequencing data were analyzed using the programs in the QIIME2 (version 2018.4) pipeline. Similarly, volatile organic compounds were extracted prior to analysis of targeted VOCs using a GC–MS. The project was designed as a split-plot design and was analyzed using R packages (version 3.4.3), lme4, lmerTest, and emmeans. Least squares means were separated using an α of 0.05.ResultsThe top orders of bacteria found in the meat samples were from Enterobacteriales, Lactobacillales, and Pseudomonadales. No differences (P ≥ 0.05) in Faith’s Phylogenetic Diversity Index, or a measure of diversity of the bacterial species within a sample, were observed between Days 0, 2, and 4 of retail case display. A targeted analysis identified eighteen VOCs associated with ground beef spoilage. In previous studies, the presence of hexanal, acetoin and acetic acid are identified as spoilage indicators. Hexanal, Acetoin and acetic acid increased (P ≤ 0.05) over the 5 d of retail display.ConclusionThe use of 16s rRNA amplicon sequencing technology is a relatively recent tool that has rapidly advanced the study of microbial deterioration during beef storage and shelf-life. Moreover, the combination of 16s rRNA amplicon sequencing and identification of VOCs in this study, afforded an exploration of the relationship between chemical and biological changes which occur during ground beef storage. These analytical technologies, when used in unison, can highlight the dynamic relationships and evolution of chemical and biological constituents in ground beef. Further research in ground beef shelf-life should incorporate such measures.

Monitoring of Pathogenic Bioaerosols in Beef Slaughter Facilities Based on Air Sampling and Airflow Modeling

HighlightsSignificant bioaerosol concentrations were detected in beef slaughter facilitiesAirflow was modeled in beef facilities and potential pathogens were trackedResults indicate transport of bioaerosols toward chiller with final food productNew ventilation designs indicate that plant sanitation can be improvedAdditional studies are required to verify effectiveness of new ventilation Abstract. and Shiga toxin producing (STEC) have long been recognized as pathogens of concern in meat products due to the prevalence of these microorganisms in the gastrointestinal tract and hide of livestock. Bacterial ingestion due to contaminated food products causes a great economic burden from the hospitalization and death of those who become infected. Recently, aerosolized bacteria have been recognized as a threat to human health and shelf life of food. In beef processing facilities, the majority of harmful bacteria are introduced by the cattle. Heating, ventilation, and air conditioning (HVAC) systems can harbor and transport these microscopic organisms. Salmonella and STEC cause 78 billion dollars lost every year due to contaminated food. During the harvesting process, these pathogens may become aerosolized from the carcasses by various mechanisms, including worker activity and airflow from HVAC systems. Although bacteria are robust creatures, environmental conditions including ventilation can be manipulated to disrupt their proliferation. In this study, one rural and one small beef facility were examined. High air volume wetted wall cyclone bioaerosol samplers capable of collecting and concentrating bioaerosols in a liquid effluent were used during the entire processing at bleeding, de-limbing, de-hiding, washing, and chiller locations. Bioaerosols were analyzed using microbial plating, quantitative Polymerase Chain Reaction, and microbiome analysis. Total bacteria counts, STEC, and concentrations were enumerated in the air and critical areas were identified. and STEC were found to increase with each passing day in the facility, as well, total counts and STEC increased between morning and afternoon phases of processing. Significant differences in total counts and temperature were found at different locations in the facilities. Blueprints were obtained from the examined facilities and the cattle processing floors were modeled using computational fluid dynamics. The airflow created from the HVAC systems was found to have a significant effect on the spread of bioaerosols. Similarities were found between the collected concentrations of bioaerosols and particle traces in the modeled facilities. Finally, new ventilation models were generated to significantly increase the sanitation of the beef slaughtering process. Keywords: Airflow pattern, Beef processing facilities, Bioaerosols, Computational fluid dynamics modeling (CFD), Displacement ventilation, Wetted Wall Cyclone (WWC).

Modified Atmospheric Packaging and Antioxidant Enhancement Improves Redness of Atypical Dark-Cutting Beef

ObjectivesDark-cutting carcasses occur when muscle pH does not decrease sufficiently during rigor mortis because of antemortem glycogen depletion. Typical dark-cutting beef have a pH > 6.0, however, atypical dark-cutting (ADC) beef have a pH around 5.7- 5.9 but have a darker lean color similar to dark-cutting beef. Previous studies noted that greater muscle pH in dark-cutting beef increase oxygen consumption and decrease myoglobin oxygenation. However, limited research has determined the biochemical basis of ADC. Therefore, the objectives of this study were to characterize the biochemical basis of ADC beef carcasses and to utilize modified atmosphere packaging (MAP) and rosemary enhancement to improve appearance during retail display.Materials and MethodsStrip loins from ADC and USDA Low Choice (C) carcasses were selected from a commercial beef processing plant and transported to the Food and Agricultural Products Center in Stillwater, OK. Control (C) and ADC steaks (prior to enhancement and packaging) were utilized to measure pH, color, oxygen consumption, and proximate compositions. Loin sections were cut into halves and randomly assigned to combinations of packaging types and enhancement treatment. Packaging included high-oxygen MAP (HiOx-MAP; 80% oxygen and 20% carbon dioxide), carbon monoxide MAP (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2), and PVC. Enhancement includes 0.1% rosemary oleoresin pumped to 10% of loin green weights. Following enhancement and packaging, steaks were displayed under retail conditions for 6 d to measure color changes using a HunterLab spectrophotometer. The data were analyzed using the Mixed Procedure of SAS, and the experiment was replicated 13 times (n = 13).ResultsThere were no differences for initial pH or proximate compositions (P < 0.05) between C and ADC. However, ADC had lower initial lightness (L* values), redness (a* values), and red intensity (chroma) compared with C. Further, ADC had greater (P < 0.05) oxygen consumption than C. There was a significant packaging × enhancement × display time interaction resulted for L*, a*, and chroma. CO-MAP and HiOx-MAP in combination with rosemary enhancement improved (P < 0.05) redness of ADC by 61.7% and 42.3%, respectively, compared with ADC in PVC packaging. Similarly, MAP and enhancement improved lightness (L* values) and chroma compared with ADC in PVC. By Day 6 of display, enhanced ADC steaks packaged in both HiOx-MAP and CO-MAP had similar color parameters to control choice steaks; however, non-enhanced ADC steaks had significantly lower a* (P < 0.0001) and chroma (P < 0.01) values when packaged in HiOx-MAP when compared to both C and enhanced ADC.ConclusionThe results suggest that ADC beef has greater oxygen consumption than C steaks even at similar muscle pH. Use of modified atmospheric packaging in combination with enhancement has the potential to improve surface color of ADC beef.

Comparison of Fatty Acid Content between New Zealand Grass-Fed and American Grain-Fed Beef Strip Loins Varying in Marbling Level

ObjectivesMarbling impacts eating quality and consumer preference of beef as it intensifies flavor, and improves tenderness and juiciness. Triglycerides are the predominate lipid in beef and are considered neutral fatty acids, whereas polar fatty acids are found in the phospholipid portion of beef. Diet of cattle during the finishing period can impact type and saturation of fatty acids in meat.The objective of this research was to evaluate differences in neutral and polar lipid fatty acid content from grass-fed and grain-fed beef of varying quality grades sourced from New Zealand and the United States, respectively.Materials and MethodsBeef strip loins (n = 200) representing two fed cattle types (n = 100/finishing type: grass-finished and grain-finished) and five different USDA quality grades (n = 20 per quality grade: USDA Standard, Select, Low Choice, “Top” Choice: High and Average Choice, and Prime) were acquired from beef processing facilities in New Zealand (grass-fed) and Nebraska (grain-fed). A face steak was cut from the anterior end of each strip loin for fatty acid analysis. Face steaks (n = 200) were frozen and stored at the Gordon W. Davis Meat Science Laboratory until further fabrication. Samples were thawed for 12 to 24 h, trimmed of subcutaneous fat and connective tissue and ground. The ground sample was frozen in liquid nitrogen and homogenized for fatty acid analysis. Lipids were extracted, fractionated into neutral lipid (NL) and polar lipid (PL), derivatized to fatty acid methyl esters and determined by gas chromatography.Statistical analyses were conducted using the procedures of SAS (Version 9.3; SAS Inst. Inc., Cary, NC). Treatment comparisons were tested for significance using PROC GLIMMIX with α = 0.05.ResultsInteractions of cattle diet × marbling level affected the overall concentrations (mg/g) of NL saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) (P < 0.05). Saturated fatty acid and MUFA NL concentration decreased as marbling level decreased, as grain-fed Prime was higher (P < 0.05) than all other treatments. Grain-finished and grass-finished Standard had the lowest (P < 0.05) SFA and MUFA NL concentration compared to all other treatments. Concentration of PUFA NL was higher (P < 0.05) for grain-finished Prime than grain-finished Top Choice and grass-finished Prime. No difference was found between grain-finished Low Choice and Select and grass-finished Top Choice NL concentration (P > 0.05), however all were higher (P < 0.05) than grass-finished and grain-finished Standard and grass-finished Select. A cattle diet × marbling level interaction affected the overall PL concentrations of SFA and MUFA (P < 0.05), but not PUFA (P > 0.05). Generally, polar fatty acid content increased as marbling increased for SFA and MUFA. Grain-finished PUFA PL concentration was higher (P < 0.05) than grass-finished samples. Additionally, PUFA PL concentration increased as quality grade decreased (P < 0.05).ConclusionIn conclusion, polar and neutral fatty acid content increased with increasing quality grades except for PL polyunsaturated fatty acids. Additionally, grain-finished beef steaks generally contained a higher SFA and MUFA NL concentration than grass-finished beef steaks for all quality grades except Low Choice and Top Choice.

Assessment of Beef Quality Determinants in the Retailing Premises

This study explains how infrastructure and beef processing practices in beef retailing premises (BRPs) are useful for beef purchasing decision. In this respect, features and beef retailing practices were assessed against the questionability of beef that is retailed in least developing countries (LDCs). This assessment was carried out by testing the null hypothesis that hypothesizes that BRPs in Dar es Salaam and Mbeya cities do not comply with the FAO technical requirements. The retailed beef in many BRPs is compromised with the status of the infrastructural development, the situation that may result in the questionability of the consumed beef. The Likert based information regarding 22 beef quality impacting factors (BQIF) from BRPs in Dar es Salaam and Mbeya, respectively, was analyzed with respect to the gaps identified and beef retailing conceptual model. This study is important as it provides general picture in connection to the status of the assessed BQIF in BRPs for the cities in the least developing countries (LDCs). In this regard, the study has shown that the compliance of BRPs in the LDCs’ cities is too weak to meet the infrastructural technical requirements due to existence of more stringent provisions in the developed specifications. The study finally identified the local infrastructural beef quality determinants in LDCs’ BRPs as the gap to be bridged by other studies.

Investigating the Etiology of Increased Incidence of Sour Knuckles in Commercial Beef Processing Facilities

Investigating the Etiology of Increased Incidence of Sour Knuckles in Commercial Beef Processing Facilities

Technological innovations in jerked beef processing: Review

The various productive chains that make up the agroindustrial system of meat undergo constant technological innovations. Innovations introduced in the processing of jerky gave rise to "Jerked Beef". The objective of this study was to present the latest technological innovations available in the scientific literature on the processing of Jerked Beef, which have contributed to guarantee quality, prolong shelf life and good acceptance of the product in the internal and external consumer market. For that, a meta-analysis of the data obtained in bibliographical research and consultation of scientific publications in the main databases of the Agrarian Sciences and Food Technology area was carried out. In this context, the research pointed out that several important advances have been conducted by researchers aimed at improving the techniques used in the processing of Jerked Beef, which are presented in the study in focus.

Dynamics of Biofilm Formation by Salmonella Typhimurium and Beef Processing Plant Bacteria in Mono- and Dual-Species Cultures.

This study aimed to determine the impact of bacteria from a beef plant conveyor belt on the biofilm formation of Salmonella in dual-species cultures. Beef plant isolates (50) including 18 Gram-negative aerobes (GNA), 8 Gram-positive aerobes (GPA), 5 lactic acid bacteria (LAB), 9 Enterobacteriaceae (EB), and 10 generic Escherichia coli (GEC) were included for developing biofilms in mono- and co-culture with S. Typhimurium at 15°C for 6days. Five selected cultures in planktonic form and in biofilms were tested for susceptibility to two commonly used sanitizers (i.e. E-San and Perox-EPlus). In mono-cultures, ≥ 80, 67, 61, 20, and 13% of GEC, EB, GNA, LAB, and GPA, respectively, developed measurable biofilms after 2days, while all co-culture pairings with S. Typhimurium achieved some level of biofilm production. The predominant effect of EB and only effect of GEC strains on the biofilm formation of S. Typhimuriumwas antagonistic, while that of Gram-positive bacteria was synergistic, with the effect being more prominent on day 6. The effect was highly variable for the GNA isolates. Six aerobic isolates that formed moderate/strong biofilms by day 2 greatly boosted the co-culture biofilm formation. Seven Gram-negative bacteria were antagonistic against the biofilm formation of the co-cultures. Both sanitizers completely inactivated the selected planktonic cultures, but were largely ineffective against biofilms. In conclusion, all beef plant isolates assessed formed biofilms when paired with S. Typhimurium. Aerobic biofilm formers may create a more favorable condition for Salmonella biofilm formation, while some beef plant isolates have potential as a biocontrol strategy for Salmonella biofilms.

Co‐products of beef processing enhance non‐haem iron absorption in an in vitro digestion/caco‐2 cell model

SummaryBeef processing produces high volumes of protein rich, low value, ‘waste’ co‐products such as offal. Beef improves uptake of low bioavailable non‐haem iron (found in vegetables, fortificants, supplements) and this effect is dubbed the ‘meat‐factor’, although the underlying mechanism is not fully understood. Here, we investigate whether bovine co‐products (kidney, lung, heart) not previously studied share this enhancing potential. This was determined by coupled in vitro digestion of co‐products and subsequent caco‐2 cell ferritin formation (an intracellular iron storage protein). In this study we show that bovine co‐products significantly increase caco‐2 cells’ response to non‐haem iron from infant rice cereal. The presence of these co‐products, (kidney, lung and heart), increased relative uptake (by 207.13%, 171.21%, 265.28%, respectively), to a greater extent than beef (30.23%). Our findings present a novel function for co‐products of beef processing that may have potential as food ingredients to improve non‐haem iron bioavailability, thus adding value.

Antimicrobial resistance and genotypic profiles of Salmonella Saintpaul isolated along beef processing and distribution continuum

Salmonella Saintpaul (SSa) is increasingly reported from food and foodborne outbreak cases. Pulsed field gel electrophoresis (PFGE) is used for screening and tracking of Salmonella infections. Widespread use of antimicrobial agents in humans and food animals could result in antimicrobial resistant Salmonella serotypes. The aim of this study was to characterize S. Saintpaul (n = 28) isolated from various sampling locations at abattoir and meat processing plant lines in Ethiopia for phenotypic antimicrobial resistance and genotypic diversity, and to track its transfer routes. Sampling location, steps and occasions were considered for each isolate description. Antimicrobial sensitivity testing was performed against seven different antimicrobial agents using disc diffusion method. PFGE with XbaI® enzymatic genomic digestion with BioNumerics® analysis was used for genotypic diversity. Of all the isolates tested, only 17.9% were pan susceptible, and 82.1% were resistant to at least one and at most to three antimicrobials. All isolates were susceptible to gentamycin, trimethoprim-sulfamethoxazol and trimethoprim. Resistance to oxytetracycline (82.2%) was predominant followed by 3.6% resistance to each of chloramphenicol, neomycin and polymyxin B. PFGE analysis revealed three distinguishable clusters of pulsotypes but the majority of the isolates (25/28) belonged to cluster-I (SSaX1-4) pulsotype. Indistinguishable/similar cluster of (SSaX 1-4) isolates among and between sampling location, steps and occasions were observed. Majorities of S. Saintpaul (88%) in the cluster-I pulsotype were resistant to oxytetracycline. Our study indicated that oxytetracycline resistance is very common among the S. Saintpaul isolates studied; and the isolates were diverse with similar resistance profiles within the same genomic pulsotypes. Transfer of S. Saintpaul within, between and across sampling locations, during the same or different occasion were determined from SSaX 1-4 pulsotype while cluster-II (SSaX5) indicates transfer from abattoir to butchery. The unique isolate in cluster-III (SSaX6) shows the presence of other possible source of S. Saintpaul for the beef chain contamination.

The effect of different temperature-time combinations when ageing beef: Sensory quality traits and microbial loads

The ageing of beef is essential to provide a tender product which is deemed acceptable by consumers, with beef processors routinely ageing beef for ~ 14 d at 0–2 °C. The rate of tenderisation is directly affected by temperature, and as such the possibility of decreasing the required ageing time by increasing storage temperature could provide an opportunity to decrease associated costs. To test this, 320 beef M. longissimus lumborum portions were subjected to one of 72temperature-time combinations (TTC) incorporating temperatures of 3, 5 or 7 °C and ageing times of 6, 8, 10 or 12 d, with some temperature changes occurring during ageing. Controls (n = 32) were held at ~ 1 °C for 14 d. The application of TTCs did not affect beef quality, however longer storage at higher temperatures resulted in higher microbial loadings. Therefore, it can be concluded that shorter, cooler TTCs could be implemented to decrease ageing time requirements and maintain beef safety.

Assessment of water and energy use at process level in the U.S. beef packing industry: Case study in a typical U.S. large‐size plant

AbstractFood processing industries consume intensive water and energy to produce food products. However, their water and energy data are scarce and require for good measurement approaches. This study presents data collection and analysis of process‐level water and energy use in a large‐size U.S. beef packing plant through a combined use of portable and in‐line meters and theoretical calculations. The kill floor and plant cleaning are the primary water users, accounting for 28.7 and 24.0%, respectively. The refrigeration compressor system is the largest user of electricity, consuming 24.5% of plant‐wide electricity. Heating of water for plant cleaning and food safety purposes is the largest thermal energy use in summer (81%) and second‐largest in winter (49.7%), with unit heating values of 625 and 666 MJ/ton live cattle weight in the summer and winter, respectively. Twice as much thermal energy is used in the winter than summer due to space heating requirements. A regression analysis found that as outdoor temperatures increased, a slight water use increase and larger energy use decrease were observed.Practical applicationsCurrently available data on water and energy use in the U.S. beef packing industry are scarce, thus limiting the ability to develop new water and energy efficient technologies and policies based on an understanding of the current baseline operations. The current study conducts a detailed assessment of water and energy use at process level to enhance the understanding of the food‐energy‐water nexus in the beef processing industry, where limited data are available. Engineers can apply this case study as an example to share with their clients seeking to collect and analyze data with the goal of identifying water and energy conservation approaches. These results will inform beef processing researchers as they design novel technologies with that may result in improved water and energy efficiencies.

Study of different extraction methods on finger print and fatty acid of raw beef fat using fourier transform infrared and gas chromatography-mass spectrometry

Abstract Beef fat was an extracted fat that a byproduct of beef processing industry. In this research, the objective was to study the effect of extraction methods on finger prints and fatty acid profiles of beef fat and to obtain the chosen extraction method. This study consisted of two steps namely extracting beef fat using Soxhlet, Folch, Bligh and Dyer, and Hara and Radin methods as well as characterizing the finger print using FTIR and fatty acid profiling using GCMS. The total lipid by Soxhlet, Folch, Bligh &amp; Dyer, and Hara &amp; Radin methods were 89.67%, 81.73%, 55.16%, and 84.40%, respectively. Statistical analysis showed that the saturated fatty acid in Folch was not significantly different with that in Soxhlet and Hara and Radin at a 5% level. Polyunsaturated fatty acids such as linoleic and linolenic acids are present in all methods, where linoleic acid was the highest in Folch and linolenic acid was the lowest in Bligh and Dyer. The PCA analysis showed that only Folch that can be differentiated and has minimal residual error values. The results of the finger print analysis showed the extraction methods which were used are not different. These data showed that Folch was the chosen method for extracting beef fat.

Effect of chitosan, and bacteriocin – Producing Carnobacterium maltaromaticum on survival of Escherichia coli and Salmonella Typhimurium on beef

The aim of this study was to investigate the synergistic effect of chitosan and bacteriocins against Escherichia coli and Salmonella in media and in lean beef. The inhibitory effects of chitosan and bacteriocins against E. coli AW1.7 and S. enterica Typhimurium in media were determined by a critical dilution assay. The efficacy a bacteriocin-producing strain of Carnobacterium maltaromaticum and high molecular weight chitosan (HMWC) in inactivation of E. coli AW1.7 and S. Typhimurium was evaluated on beef. Current interventions applied in the beef industry, steaming coupled with lactic acid, were used as reference. HMWC demonstrated higher antibacterial activity than water soluble chitosan (WSC) or chitosan oligosaccharides (COS) in media, and the addition of partially purified bacteriocins from C. maltaromaticum UAL307 increased the activity of the chitosan in vitro. The hurdle combinations associated with HMWC inactivated E. coli AW1.7 and S. enterica Typhimurium more effectively on lean beef when compared to steam or steam coupled with lactic acid. When used on beef, addition of bacteriocins and chitosan did not increase the antibacterial efficacy. Cell counts of S. enterica were further reduced during storage in presence of C. maltaromaticum and chitosan; however, this decrease was not dependent on bacteriocin production. In conclusion, addition of chitosan alone or in combination with C. maltaromaticum UAL 307 as protective culture significantly reduces cell counts of E. coli and Salmonella on beef. Results will be useful to improve pathogen intervention treatments in beef processing.

Novel Continuous and Manual Sampling Methods for Beef Trim Microbiological Testing

A sampling method that represents a greater proportion of the beef trimmings in a 900-kg combo bin should improve the current pathogen sampling and detection programs used by fresh beef processors. This study compared two novel, nondestructive sampling methodologies (a continuous sampling device [CSD] and a manual sampling device [MSD]) with the current industry methodologies, the N60 Excision (the "gold standard") and N60 Plus, for collection of trim samples. Depending on the experiment, samples were analyzed for naturally occurring Escherichia coli O157:H7 or Salmonella, inoculated surrogates, or indicator organisms in multiple plants, on multiple days, across multiple lean percentage mixtures. Experiments 1A and 1B with natural contamination found no E. coli O157:H7 but similar ( P > 0.05) prevalence of Salmonella (CSD 9.2% versus N60 Excision 6.0%) and similar ( P > 0.05) levels of indicator organisms for CSD compared with both N60 methodologies. In experiments 2 and 3, CSD cloth sampling had the same or higher prevalence of naturally occurring E. coli O157:H7 and E. coli O157:H7 surrogate organisms, as well as similar levels of indicator organisms compared with the N60 methodologies. In experiment 4, MSD cloth sampling detected similar ( P > 0.05) prevalence of E. coli O157:H7 surrogate organisms, as well as slightly lower ( P < 0.05) levels of indicator organisms compared with N60 Plus. In experiment 5, the MSD found similar ( P > 0.05) prevalence of naturally occurring E. coli O157:H7 and the same or slightly higher ( P < 0.05) levels of naturally occurring indicator organisms compared with N60 Plus. In experiment 6, the MSD detected the same ( P > 0.05) prevalence of naturally occurring Salmonella as did N60 Excision. The results of these experiments collectively demonstrate that sampling beef trim using either the CSD or MSD provides organism recovery that is similar to or better than the N60 Excision or the N60 Plus methodologies.

The Characterization of Biofilm Formation and Detection of Biofilm-Related Genes in Salmonella Isolated from Beef Processing Plants

The biofilm formation behavior of Salmonella isolated from beef processing plants was investigated under varying temperatures (4°C, 10°C, 25°C, 37°C, and 42°C) and pH (4.5, 5.0, 5.5, 6.0, 7.0, and 8.0). The relationships between the presence of biofilm-related genes and the biofilm formation capacity were evaluated. A total of 77 Salmonella strains in 8 different serotypes were assessed: Salmonella Agona (n = 43), Salmonella Senftenberg (n = 13), Salmonella Meleagridis (n = 8), Salmonella Derby (n = 7), Salmonella Kottbus (n = 2), Salmonella Calabar (n = 2), Salmonella Kingston (n = 1), and Salmonella Typhimurium (n = 1). The results showed that all tested Salmonella strains produced biofilm at 25°C and 37°C after 3 d, and Salmonella Kingston and Salmonella Senftenberg had higher biofilm production than other strains under test conditions. Serotype, incubation temperature, pH, and their interactions had significant effects on biofilm formation for Salmonella. The strongest biofilm formation capacity of Salmonella (serovar Agona, Senftenberg, Kottbus, Calabar, Kingston, and Typhimurium) occurred at 25°C and at pH 7.0. Biofilm formation was significantly inhibited for all Salmonella strains incubated at 4°C. The detection rates of genes rpoS, fliC, wcaA, and invA were 100%, and the rates of genes csgB, csgD, csrA, sirA, adrA, gly, fimH, sdiA, ompR, sipB, sipC, luxS, and pfs exceeded 75% among all biofilm producer strains. The detection rate of igaA was significantly different between different biofilm producers. Based on the findings in this study, useful information on biofilm formation of Salmonella isolated from beef processing plants in China is provided, which could help clear the technological hurdle in delaying biofilm production to deal with risks from Salmonella biofilms in the beef industry.

Factores internos de gestión de recursos humanos que influyen en la productividad laboral del procesamiento de la carne vacuna en el frigorífico Piquete Cué, instalado en la ciudad de Limpio, en el año 2016

Factores internos de gestión de recursos humanos que influyen en la productividad laboral del procesamiento de la carne vacuna en el frigorífico Piquete Cué, instalado en la ciudad de Limpio, en el año 2016

Collusion-enhancing effects of the own- and cross-price demand elasticities in merging multiproduct food industries: The case of chicken and red meat in the United States

The recent wave of megamergers sweeping the US food industry has raised significant concerns regarding “conglomerate” market power. Beef processors have been merging with pork and/or poultry processors (and vice versa). Concurrently, consumers have changed their attitude toward diet and health. The poultry industry has been more responsive to the changes in consumers’ lifestyles than the red meat industry by providing products which address health concerns. As a consequence, consumers exhibit stronger preference for chicken and are more willing to substitute chicken for red meat. The objective of this study is to examine the sustainability of collusion between multiproduct meat processing firms, under different values of the own-price demand flexibility of chicken as well as cross-price elasticities of demand between the markets of chicken and red meat. The findings indicate that the less (more) responsive demand for chicken gets to changes in its own price (price of red meat), the easier it gets for firms to sustain collusion.

Use of Nonpathogenic Escherichia coli Surrogates as Predictors of the Survival of Nontyphoidal Salmonella, non-O157 Shiga Toxin–Producing Escherichia coli, and Escherichia coli O157 Populations after High Hydrostatic Pressure Processing

Validated surrogates are a useful tool for studying the response of pathogens to food safety interventions, but better surrogates are needed for studies using high pressure processing. Ground beef (85% lean, 15% fat) was inoculated separately with mixed cultures of Escherichia coli O157, non-O157 Shiga toxin-producing E. coli, nontyphoidal Salmonella, and nonpathogenic E. coli surrogate bacteria. The inoculated ground beef was subjected to high hydrostatic pressures of 200, 400, and 600 MPa for 4, 6, and 8 min at each pressure. High pressure processing at 200 MPa reduced the inoculated populations of the pathogenic bacteria by 0.9 to 1.8 log CFU/g, 400 MPa reduced the inoculated populations by 2.5 to 3.6 log CFU/g, and 600 MPa reduced the inoculated populations by 4.5 to 5.6 log CFU/g. The nonpathogenic E. coli surrogates were more resistant to the effects of high pressure processing than were the inoculated pathogen populations. This finding suggests that the nonpathogenic E. coli surrogates could be used as process control indicators for high pressure processing of ground beef to predict a specific level of pathogen reduction. The surviving populations of the potential surrogate bacteria were proportional to the surviving populations of the pathogenic bacteria. The models allow for an estimation of the potential surviving populations of the pathogenic bacteria based on quantitative results of the populations of the surrogate bacteria.