Simulated Commercial Processing Research Articles

Research Note: Fate and dissemination of Salmonella enterica serovar reading in turkeys at processing using an oral gavage challenge model

This study aimed to evaluate the fate and dissemination of Salmonella Reading (SR) in turkeys using an oral gavage challenge model. One hundred twenty-eight-week-old commercial turkey hens were moved from commercial production to research facilities. Upon arrival, a combination of enrofloxacin, 10 mg/kg, and florfenicol, 20 mg/kg, were orally administered sequentially before comingled placement on fresh pine shavings. Turkeys were challenged with 108 cfu SR by oral gavage on d 4 and 7 postplacement. Subsets were subjected to simulated commercial processing on d 14 (n = 40), 21 (n = 40) and 28 (n = 32) postplacement (corresponding to 10, 11, and 12 wk of age). Stifle joint, skin, trachea, crop, lung, liver + spleen (LS), and ceca were aseptically sampled and cultured for Salmonella recovery and serotyping. SR could not be recovered from stifle joint 14 d post inoculation (PI). However, at 14 d PI, recovery of SR were: Skin 80%; crop 75%; LS 67.5%; lungs 60%; and ceca 57.5%. (P < 0.01). Interestingly, the lowest recovery of SR was observed from trachea (40%). At 21 d PI, the highest rate of positive samples to SR were observed in ceca (87.5%) and crop (67.5%). By 28 d PI, SR was only recovered from ceca (75%); crop (43.8%); lung (34.4%); and LS (21.9%). The results of this study confirms that SR is an emerging problem for the turkey industry and immediate measurements to reduce foodborne pathogens such as Salmonella should target all parts of the supply chain and consumer education about food safety.

Efficacy of Lactic Acid, Lactic Acid–Acetic Acid Blends, and Peracetic Acid To Reduce Salmonella on Chicken Parts under Simulated Commercial Processing Conditions

The poultry processing industry has been undergoing a series of changes as it modifies processing practices to comply with new performance standards for chicken parts and comminuted poultry products. The regulatory approach encourages the use of intervention strategies to prevent and control foodborne pathogens in poultry products and thus improve food safety and protect human health. The present studies were conducted to evaluate the efficacy of antimicrobial interventions for reducing Salmonella on inoculated chicken parts under simulated commercial processing conditions. Chicken pieces were inoculated by immersion in a five-strain Salmonella cocktail at 6 log CFU/mL and then treated with organic acids and oxidizing agents on a commercial rinsing conveyor belt. The efficacy of spraying with six different treatments (sterile water, lactic acid, acetic acid, buffered lactic acid, acetic acid in combination with lactic acid, and peracetic acid) at two concentrations was evaluated on skin-on and skin-off chicken thighs at three application temperatures. Skinless chicken breasts were used to evaluate the antimicrobial efficacy of lactic acid and peracetic acid. The color stability of treated and untreated chicken parts was assessed after the acid interventions. The lactic acid and buffered lactic acid treatments produced the greatest reductions in Salmonella counts. Significant differences between the control and water treatments were identified for 5.11% lactic acid and 5.85% buffered lactic acid in both skin-on and skin-off chicken thighs. No significant effect of treatment temperature for skin-on chicken thighs was found. Lactic acid and peracetic acid were effective agents for eluting Salmonella cells attached to chicken breasts.

Postharvest Reduction of Coliphage MS2 from Romaine Lettuce during Simulated Commercial Processing with and without a Chlorine-Based Sanitizer

Viral foodborne outbreaks are a serious threat to public health, and fresh produce is becoming increasingly recognized as a transmission vehicle. To limit foodborne disease, ready-to-eat leafy greens are typically washed with a chlorine-based sanitizer during commercial production. This study assessed the efficacy of a chlorine-based sanitizer against coliphage MS2, as a potential surrogate for foodborne viruses, on fresh-cut romaine lettuce during simulated commercial production using a small-scale processing line. Before processing, romaine lettuce was inoculated to contain approximately 105 and 106 PFU/g of MS2 for experiments with and without sanitizer, respectively. Lettuce samples were collected following each stage of processing, which included mechanical shredding, 2 min of flume washing (with or without 25 ppm of free chlorine), shaker table dewatering, and centrifugal drying. In addition, the spent centrifuge water and flume wash water were collected, with the flume water concentrated using hollow-fiber ultrafiltration. MS2 was recovered from lettuce in Tris-glycine buffer and quantified as PFUs in a double-agar overlay assay. The greatest reduction in MS2 occurred between shredding and flume washing, with levels remaining relatively stable following flume washing with or without 25 ppm of free chlorine. Average total reductions of 0.8 and 1.0 log PFU/g were seen after processing with and without the sanitizer, respectively, with no statistical difference observed between the two treatments (P > 0.05). The average MS2 level in the spent centrifugation water started at 4.0 log PFU/ml for experiments with sanitizer and the average MS2 reduction in the flume wash water was 4 log (PFU) for experiments with sanitizer, demonstrating that removals could be achieved in the water itself. These findings suggest that the currently recommended commercial production practices are unable to effectively decrease viruses once they have attached to leafy greens during commercial processing.

Validation of Organic Acid Interventions in Chicken Thighs to Reduce Salmonella under Simulated Commercial Processing Conditions

Validation of Organic Acid Interventions in Chicken Thighs to Reduce Salmonella under Simulated Commercial Processing Conditions

Antagonistic effect of Pseudomonas graminis CPA-7 against foodborne pathogens in fresh-cut apples under simulated commercial conditions

Recently, we reported that the application of the strain CPA-7 of Pseudomonas graminis, previously isolated from apple, could reduce the population of foodborne pathogens on minimally processed (MP) apples and peaches under laboratory conditions. Therefore, the objective of the present work was to find an antioxidant treatment and a packaging atmosphere condition to improve CPA-7 efficacy in reducing a cocktail of four Salmonella and five Listeria monocytogenes strains on MP apples under simulated commercial processing. The effect of CPA-7 application on apple quality and its survival to simulated gastric stress were also evaluated. Ascorbic acid (2%, w/v) and N-acetyl-l-cysteine (1%, w/v) as antioxidant treatments reduced Salmonella, L. monocytogenes and CPA-7 recovery, meanwhile no reduction was observed with NatureSeal® AS1 (NS, 6%, w/v). The antagonistic strain was effective on NS-treated apple wedges stored at 10 °C with or without modified atmosphere packaging (MAP). Then, in a semi-commercial assay, efficacy of CPA-7 inoculated at 105 and 107 cfu mL−1 against Salmonella and L. monocytogenes strains on MP apples with NS and MAP and stored at 5 and 10 °C was evaluated. Although high CPA-7 concentrations/populations avoided Salmonella growth at 10 °C and lowered L. monocytogenes population increases were observed at both temperatures, the effect was not instantaneous. No effect on apple quality was detected and CPA-7 did not survived to simulated gastric stress throughout storage. Therefore, CPA-7 could avoid pathogens growth on MP apples during storage when use as part of a hurdle technology in combination with disinfection techniques, low storage temperature and MAP.

Microbiological and organoleptic characteristics of beef trim and ground beef treated with acetic acid, lactic acid, acidified sodium chlorite, or sterile water in a simulated commercial processing environment to reduce Escherichia coli O157:H7 and Salmonella

The objective of this study was to validate the effectiveness of acetic and lactic acids (2% and 5%), acidified sodium chlorite (1000ppm), and sterile water in reducing Escherichia coli O157:H7 and Salmonella Typhimurium in inoculated beef trim in a simulated processing environment. Samples were collected to assess microbial characteristics at three processing points. Results from this study indicate that all treatments, including sterile water, reduced pathogen concentrations (P<0.05) of both E. coli O157:H7 and Salmonella Typhimurium in ground beef up to 0.5 and 0.6 log by 24h, respectively. In some cases, there were no significant differences between the antimicrobial treatments and the sterile water using this application method. Triangle sensory test results of non-inoculated beef indicated there were no differences (P<0.05) in the means of correct responses between controls or antimicrobial treatments at 6 or 24h. While interventions are important for beef trim, use of the interventions must be validated under industry conditions to ensure proper effectiveness.

Efficacy of sanitizers in reducing Escherichia coli O157:H7, Salmonella spp. and Listeria monocytogenes populations on fresh-cut carrots

Shredded carrots were inoculated with Escherichia coli O157:H7, Salmonella or Listeria monocytogenes and washed for 1 or 2 min with chlorine (Cl; 200 ppm), peroxyacetic acid (PA; 40 ppm) or acidified sodium chlorite (ASC; 100, 200, 500 ppm) under simulated commercial processing conditions. After washed, the carrots were spin dried, packaged and stored at 5 °C for up to 10 days. Bacterial enumeration was significantly ( P ⩽ 0.05) reduced by 1, 1.5 and 2.5 log CFU/g after washing with ASC 100, 250 and 500 ppm, respectively. All sanitizers reduced pathogen load below that of tap water wash and unwashed controls. During storage at 5 °C the bacterial load of all treatments increased gradually, but to different extent in different treatments. ASC inhibited bacterial growth more effectively than the other sanitizers and also maintained the lowest pathogen counts (<1 log CFU/g) during storage. Organic matter in the process water significantly ( P ⩽ 0.05) reduced the antibacterial efficacy of Cl, but not that of PA or ASC. Therefore, ASC shows the potential to be used as a commercial sanitizer for washing shredded carrots.

On suitability of novel fluidised bed technique for separation of metallic powders during commercial powder metallurgical processing

Experiments have been performed to test the efficiency with which a novel fluidised bed technique could separate different metallic powders in terms of size and density. The overall aim was to assess the potential of this technique for the commercial separation of defective powder fractions from mechanically alloyed (MA), iron based powders. Separation in terms of size was readily achieved, with the largest powder particles sinking to the bottom of the fluidised bed. In a simulated commercial process, density separation of defective Fe3Al powder could not be demonstrated as any differences in density were overshadowed by size and morphology differences. However, from a batch of iron based powder (ρ=8·02 g cm−3), seeded with six other metallic powders, aluminium powder (ρ=2·70 g cm−3) segregated strongly to the top of the bed from where samples containing 93 vol.-%Al were taken. The process is thought to be sensitive to differences in density of a factor of 1.1–3.

Efficacy of Chlorine and a Peroxyacetic Acid Sanitizer in Killing Listeria monocytogenes on Iceberg and Romaine Lettuce Using Simulated Commercial Processing Conditions

The efficacy of chlorine (100 μg/ml) and a peroxyacetic acid sanitizer (80 μg/ml; Tsunami 100) in killing Listeria monocytogenes inoculated at populations of 1 to 2, 2 to 3, and 4 to 5 log CFU/g of iceberg lettuce pieces, shredded iceberg lettuce, and Romaine lettuce pieces was determined by treatment conditions simulating those used by a commercial fresh-cut lettuce processor. The lettuce/treatment solution ratio was 1:100 (wt/vol), treatment temperature was 4°C, and total treatment time was 30 s. Compared with washing in water, treatment of iceberg lettuce pieces containing all levels of inoculum and shredded iceberg lettuce containing 2 to 3 or 4 to 5 log CFU/g with chlorine or Tsunami resulted in significant reductions (P ≤ 0.05) of pathogen populations. Populations recovered from Romaine lettuce pieces treated with chlorine or Tsunami were not significantly different from populations recovered from pieces washed with water, regardless of the inoculum level. Within lettuce type and inoculum level, in no instance was the number of L. monocytogenes recovered from lettuce treated with chlorine or Tsunami significantly different. The rate of decrease in free chlorine concentration in treatment solution as affected by the weight/volume ratio (1:100, 1:10, 2:10, and 4:10) of lettuce and solution was determined. The rate of reduction increased as the ratio decreased. The overall order of magnitude of reduction was shredded iceberg lettuce > iceberg pieces > Romaine pieces. The highest reductions in free chlorine concentration in solutions used to treat shredded lettuce are attributed to the release of tissue juices, which increases the concentration of soluble organic materials available for reaction with chlorine.

Validation of a 5-Log10 Reduction of Listeria monocytogenes following Simulated Commercial Processing of Lebanon Bologna in a Model System

Recently, numerous product recalls and one devastating outbreak that claimed 21 lives were attributed to Listeria monocytogenes in ready-to-eat meat products. Consequently, the Food Safety and Inspection Service published a federal register notice requiring manufacturers of ready-to-eat meat and poultry products to reassess their hazard analysis and critical control point plans for these products as specified in 9 CFR 417.4(a). Lebanon bologna is a moist, fermented ready-to-eat sausage. Because of undesirable quality changes, Lebanon bologna is often not processed above 48.9°C (120°F). Therefore, the present research was conducted to validate the destruction of L. monocytogenes in Lebanon bologna batter in a model system. During production, fermentation of Lebanon bologna to pH 4.7 alone significantly reduced L. monocytogenes by 2.3 log10 CFU/g of the sausage mix (P < 0.01). Heating the fermented mix to 48.9°C in 10.5 h destroyed at least 7.0 log10 CFU of L. monocytogenes per g of sausage mix. A combination of low pH (5.0 or lower) and high heating temperatures (≥43.3°C, 115°F) destroyed more than 5 log10 CFU of L. monocytogenes per g of sausage mix during the processing of Lebanon bologna. In conclusion, an existing commercial process, which was validated for destruction of Escherichia coli O157:H7, was also effective for the destruction of more than 5 log10 CFU of L. monocytogenes.

Effect of Post-Mortem Boning Time During Simulated Commercial Processing on the Tenderness of Broiler Breast Meat

Broiler breast fillets were harvested at selected times post-mortem during simulated commercial broiler processing, chilling, and aging prior to objective evaluation of cooked meat tenderness and moisture content. Fillets harvested within the first .25 h post-mortem were significantly less tender and had a lower moisture content than all other fillets, even though these fillets had a significantly greater water uptake during chilling. Fillets harvested from chillled carcasses at 1.08 to 2.33 h were significantly more tender than hot-boned fillets but significantly less tender than fillets harvested at 3.33 h or later times up to 24.33 h. Fillets harvested 24.33 h post-mortem were significantly more tender than fillets harvested at any other time. Moisture contents of fillets harvested after the chilling process were not significantly different.

Removal of chlorinated pesticides from crude vegetable oils by simulated commercial processing procedures

AbstractCrude soybean and cottonseed oil were processed using simulated commercial processing procedures to determine if oil processing would remove chlorinated pesticide contaminants of either natural or spiked origin. Two crude oil lots were spiked with endrin, DDT, DDE, aldrin, dieldrin, heptachlor and heptachlor epoxide before processing. Representative samples of crude oil and products following each processing step were analyzed for pesticide contamination. Results indicated that alkali‐refining or subsequent bleaching did not reduce chlorinated pesticide contamination. Hydrogenation prior to deodorization reduced endrin contamination. Deodorization, with or without hydrogenation, eliminated chlorinated pesticides. The results of this study indicate that normal commercial processing of crude vegetable oils for human consumption effectively removes any chlorinated pesticides which may be present in crude oils. It is hypothesized that chlorinated pesticide removal is achieved by volatilization during deodroization, which is supported by known volatilization characteristics, similarity of behavior in pesticides studied, and absence of the pesticide or its conversion products in the finished oils, or both.