Efficacy of intermittent decontamination treatments during processing in reducing the microbial load on broiler chicken carcass

Mapping foodborne pathogen contamination throughout the conventional and alternative poultry supply chains

Recently, there has been a consumer push for natural and organic food products. This has caused alternative poultry production, such as organic, pasture, and free-range systems, to grow in popularity. Due to the stricter rearing practices of alternative poultry production systems, different types of levels of microbiological risks might be present for these systems when compared to conventional production systems. Both conventional and alternative production systems have complex supply chains that present many different opportunities for flocks of birds or poultry meat to be contaminated with foodborne pathogens. As such, it is important to understand the risks involved during each step of production. The purpose of this review is to detail the potential routes of foodborne pathogen transmission throughout the conventional and alternative supply chains, with a special emphasis on the differences in risk between the two management systems, and to identify gaps in knowledge that could assist, if addressed, in poultry risk-based decision making.

Antibacterial activity of Timsen® (n-alkyl dimethyl benzyl ammonium chloride-40%) in scalding and precooling water in poultry slaughterhouses

The objective of this study was to evaluate the efficacy of a product based on n-alkyl dimethyl benzyl ammonium chloride-40%, marketed as Timsen®, during scalding and precooling of poultry carcasses in slaughterhouses. To this end, three poultry slaughterhouses (A, B and C) were evaluated. The product was added (200 ppm) to the scalding (58 °C) and precooling water (4 °C), and microbiological analyses were performed of the water and the poultry carcasses before and after Timsen® addition. The product controlled the multiplication of aerobic mesophilic microorganisms, both in the scalding as in the precooling water. In a comparison of carcasses soaked in Timsen®-treated scalding and precooling water with carcasses soaked in untreated water, the count of aerobic mesophilic microorganisms in the later was higher and thermotolerant coliform was not detected in samples of carcasses soaked in Timsen®-treated water. When the scalding and precooling water was not treated with the product, Listeria spp. was isolated from poultry carcasses of two slaughterhouses (A and C), while these microorganisms were not detected when Timsen® was applied. The use of Timsen® in the scalding and precooling water enhanced the safety and control microbial contamination of poultry carcasses.

High pressure spray with water shows similar efficiency to trimming in controlling microorganisms on poultry carcasses

A study was conducted to evaluate a high pressure spray (HPS) with water as an alternative to trimming to remove gastrointestinal contamination on poultry carcasses and improve microbiological quality. The study was conducted under commercial conditions in 5 slaughter plants with one plant presenting approximately 5% of carcasses with visible gastrointestinal contamination (VGC), and the others showing approximately 12% of VGC. In all 5 plants, carcasses were sampled from the slaughter line and separated into 6 groups corresponding to 3 different treatments: A) carcasses with VGC before and after trimming; B) carcasses with VGC before and after HPS; and C) carcasses with no VGC before and after HPS. At the end of Trial A and prior to Trials B and C, an HPS equipment was installed before the end of the slaughter line. The HPS equipment was operated with 10 kgf/cm² of pressure and 1.5 L of potable water per carcass. Carcasses were analyzed using a rinsing procedure, and the following microbiological parameters were evaluated: the prevalence of Salmonella and Campylobacter, the abundance of Escherichia coli (EC), Enterobacteriaceae (EB), and the Total Viable Count (TVC). Salmonella was found in all plants at a prevalence ranging from 0.8% (plant 1) to 17.3% (plant 5), and the difference between plants was significant (P < 0.05%). The prevalence of Campylobacter ranged from 2.1 (plant 1) to 18.6% (plant 4) (P < 0.05%). The prevalence of Campylobacter was similar in plants 2, 3, and 5, and a significant difference (P < 0.05%) was observed compared to plants 1 and 4. In all plants, the EC, EB, and TVC counts did not show a significant difference (P > 0.05%) in any treatments. These results demonstrate that HPS with water is an alternative method for removing VGC and improving or maintaining the microbiological quality and safety of broiler carcasses.

Fumaric Acid and Slightly Acidic Electrolyzed Water Inactivate Gram Positive and Gram Negative Foodborne Pathogens

Sanitizing effectiveness of slightly acidic electrolyzed water (SAEW) and fumaric acid (FA) at different dipping temperatures (25-60 °C), times (1-5 min), and concentrations (5-30 ppm for SAEW and 0.125%-0.5% for FA) on pure cultures of two Gram positive pathogens Staphylococcus aureus (SA) and Listeria monocytogenes (LM) and two Gram negative pathogens Escherichia coli O157:H7 (EC) and Salmonella Typhimurium (ST) was evaluated. FA (0.25%) showed the strongest sanitizing effect, demonstrating complete inactivation of EC, ST, and LM, while SA was reduced by 3.95-5.76 log CFU/mL at 25-60 °C, respectively, after 1 min of treatment. For SAEW, the complete inactivation was obtained when available chlorine concentration was increased to 20 ppm at 40 °C for 3 and 5 min. Moreover, Gram positive pathogens have been shown to resist to all treatment trends more than Gram negative pathogens throughout this experiment. Regardless of the different dipping temperatures, concentrations, and times, FA treatment was more effective than treatment with SAEW for reduction of foodborne pathogens. This study demonstrated that application of FA in food systems may be useful as a method for inactivation of foodborne pathogens.

Efficacy of Acetic Acid against Listeria monocytogenes Attached to Poultry Skin during Refrigerated Storage

This work evaluates the effect of acetic acid dipping on the growth of L. monocytogenes on poultry legs stored at 4 °C for eight days. Fresh inoculated chicken legs were dipped into either a 1% or 2% acetic acid solution (v/v) or distilled water (control). Changes in mesophiles, psychrotrophs, Enterobacteriaceae counts and sensorial characteristics (odor, color, texture and overall appearance) were also evaluated. The shelf life of the samples washed with acetic acid was extended by at least two days over the control samples washed with distilled water. L. monocytogenes counts before decontamination were 5.57 log UFC/g, and after treatment with 2% acetic acid (Day 0), L. monocytogenes counts were 4.47 log UFC/g. Legs washed with 2% acetic acid showed a significant (p < 0.05) inhibitory effect on L. monocytogenes compared to control legs, with a decrease of about 1.31 log units after eight days of storage. Sensory quality was not adversely affected by acetic acid. This study demonstrates that while acetic acid did reduce populations of L. monocytogenes on meat, it did not completely inactivate the pathogen. The application of acetic acid may be used as an additional hurdle contributing to extend the shelf life of raw poultry and reducing populations of L. monocytogenes.

Efficacy of ε-polylysine, lauric arginate, or acidic calcium sulfate applied sequentially for Salmonella reduction on membrane filters and chicken carcasses

Salmonella contamination continues to be one of the major concerns for the microbiological safety of raw poultry products. Application of more than one decontamination agent as a multihurdle intervention to carcasses in a processing line might produce greater reductions than one treatment alone due to different modes of action of individual antimicrobials. In this study, all possible two-way combinations and individual applications of ε-polylysine (EPL), lauric arginate (LAE), and acidic calcium sulfate (ACS) solutions were evaluated for their effects against Salmonella enterica serovars, including Enteritidis and Typhimurium, using a sterile membrane filter model system. The combinations that provided higher Salmonella reductions were further evaluated on inoculated chicken carcasses in various concentrations applied in a sequential manner. Sequential spray applications of 300 mg of EPL per liter followed by 30% ACS and of 200 mg of LAE per liter followed by 30% ACS produced the highest Salmonella reductions on inoculated chicken carcasses, by 2.1 and 2.2 log CFU/ml, respectively. Our results indicated that these sequential spray applications of decontamination agents are effective for decreasing Salmonella contamination on poultry carcasses, but further studies are needed to determine the effectiveness of these combinations over a storage period.

Combined effects of thymol, carvacrol and temperature on the quality of non conventional poultry patties

The combined effect of thymol (0-300ppm), carvacrol (0-300ppm), and temperature (0-18°C) on the quality of non conventional poultry patties packaged in air and modified atmosphere (MAP: 40% CO(2;) 30%O(2); 30% N(2)) was investigated using a simplex centroid mixture design. The patties were monitored for microbiological (total viable count, Enterobacteriaceae, lactic acid bacteria, Pseudomonas spp.) physico-chemical (pH, colour) and sensory attributes. For the patties mixed with the antimicrobials and stored at low temperature (0-3°C) a reduction of the cell load of about 1-1.5logcfu/g was observed. The log reduction was lower at the end of storage time and decreased with the increase of the temperature. For the poultry patties packaged in MAP the higher log reduction for Pseudomonas spp. during all the storage time was observed. In both packaging atmospheres the combination of the essential oils and low temperature determined no modification for off-odour during the first 4days of storage.

Predictive models for reduction of Salmonella Hadar on chicken skin during single and double sequential spraying treatments with acetic acid

AIMS

The response surface methodology was used to evaluate the effect of acetic acid concentration, spraying time and temperature on the reduction of Salmonella Hadar on poultry skin in a laboratory spraying process, and to identify the best conditions required to develop this operation.

METHODS AND RESULTS

A comparative analysis was carried out to ascertain the effects of the application of single (SS) and double sequential decontamination (DSS) treatments on skin samples inoculated with Salm. Hadar. While on the SS treatment, the linear and quadratic acid concentration terms and the interaction of the temperature and time term of the model are statistically significant at P < or = 0.001, P < or = 0.01 and P < or = 0.05, respectively, the other terms do not significantly affect (P > 0.05) the reduction of Salm. Hadar. On the DSS model the acid concentration and time linear terms significantly affected (P < or = 0.001 and P < or = 0.01) the Salm. Hadar reduction within the experimental range assayed.

CONCLUSION

Any of the models could be used as an approach to optimize spray washing during chicken processing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Neither the SS or the DSS treatment has the capability of eliminating Salm. Hadar from carcasses. However, reductions of approx. 99% initial load could be attained if DSS treatment were put into practice.

Inhibitory effect of oxalic acid on bacterial spoilage of raw chilled chicken

Oxalic acid was evaluated as a treatment for reducing populations of naturally occurring microorganisms on raw chicken. Raw chicken breasts were dipped in solutions of oxalic acid (0, 0.5, 1.0, 1.5, and 2.0%, wt/vol) for 10, 20, and 30 min, individually packed in oxygen-permeable polyethylene bags, and stored at 4 degrees C. Total plate counts of aerobic bacteria and populations of Pseudomonas spp. and Enterobacteriaceae on breasts were determined before treatment and after storage for 1, 3, 7, 10, and 14 days. The pH and Hunter L, a, and b values of the breast surface were measured. Total plate counts were ca. 1.5 and 4.0 log CFU/g higher on untreated chicken breasts after storage for 7 and 14 days, respectively, than on breasts treated with 0.5% oxalic acid, regardless of dip time. Differences in counts on chicken breasts treated with water and 1.0 to 2.0% of oxalic acid were greater. Populations of Pseudomonas spp. on chicken breasts treated with 0.5 to 2.0% oxalic acid and stored at 4 degrees C for 1 day were less than 2 log CFU/g (detection limit), compared with 5.14 log CFU/g on untreated breasts. Pseudomonas grew on chicken breasts treated with 0.5% oxalic acid to reach counts not exceeding 3.88 log CFU/g after storage for 14 days. Counts on untreated chicken exceeded 8.83 log CFU/g at 14 days. Treatment with oxalic acid caused similar reductions in Enterobacteriaceae counts. Kocuria rhizophila was the predominant bacterium isolated from treated chicken. Other common bacteria included Escherichia coli and Empedobacter brevis. Treatment with oxalic acid caused a slight darkening in color (decreased Hunter L value), retention of redness (increased Hunter a value), and increase in yellowness (increased Hunter b value). Oxalic acid has potential for use as a sanitizer to reduce populations of spoilage microorganisms naturally occurring on raw chicken, thereby extending chicken shelf life.

Application of distilled white vinegar in the cloaca to counter the increase in Campylobacter numbers on broiler skin during feather removal

Because of the escape of highly contaminated gut contents from the cloaca of positive carcasses, Campylobacter numbers recovered from broiler carcass skin samples increase during automated feather removal. Vinegar is known to have antimicrobial action. The objective of this study was to determine the effect of vinegar placed in the cloaca prior to feather removal on the numbers of Campylobacter recovered from broiler breast skin. Broilers were stunned, killed, and bled in a pilot processing plant. Vinegar was placed in the colons of the chickens prior to scalding. Carcasses were scalded, and Campylobacter numbers were determined on breast skin before and after passage through a commercial-style feather-picking machine. Campylobacter numbers recovered from the breast skin of untreated control carcasses increased during feather removal from 1.3 log CFU per sample prior to defeathering to 4.2 log afterward. Placement of water in the colon before scalding had no effect on Campylobacter numbers. Campylobacter numbers recovered from the breast skin of carcasses treated with vinegar also increased during defeathering but to a significantly lesser extent. Treated carcasses experienced only a 1-log increase from 1.6 log CFU per sample before feather removal to 2.6 log CFU per sample afterward. Application of an effective food-grade antimicrobial in the colon prior to scald can limit the increase in Campylobacter contamination of broiler carcasses during defeathering.

Predictive model for reduction of Escherichia coli during acetic acid decontamination of chicken skin

AIMS

The response surface methodology was used to evaluate the effect of operating variables (acetic acid concentration, spraying time and temperature) on the reduction of Escherichia coli populations on poultry breast skin in a laboratory showering process, as well as to identify the best conditions that are required to develop this operation.

METHODS AND RESULTS

Skin samples were inoculated with a 24-h E. coli culture and afterwards treated according to experimental design under selected acetic acid concentration, spraying time, and solution temperature. The E. coli reduction model was significantly affected by the acetic acid concentration and spraying time (P < or = 0.05 and < or =0.01), while temperature did not show a significant effect (P > 0.05).

CONCLUSION

The predictive model obtained was validated through additional confirmatory experiments and showed to be adequate, and it could be used as an approach to optimize the acetic acid spray washes during poultry carcasses processing.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of acetic acid washes in the processing of poultry does not have the capability of eliminating E. coli populations from carcasses. However, significant reductions in the initial load could be achieved.

Decontamination of broilers with hydrogen peroxide stabilised with glycerol during processing

Experiments were conducted to assess the effects of different concentrations of hydrogen peroxide stabilised by glycerol solution in potable water on the bacteriological and organoleptic quality of freshly slaughtered broiler carcasses. Skin-pH and colour were measured 3.5 and 24 h after treatment and compared to untreated carcasses. Bacterial colonisation was determined 3.5 and 24 h and, 7 days after treatment, carcasses being stored at 1 degrees C. None of the concentrations used affected the appearance and "bloom" of the carcasses as could be measured by colorimeter and changing of the acidity. Mean microbial counts were significantly reduced (P<0.01) when treated and control broilers were compared. Average reductions of 0.3 up to1.4 log N for the mesophilic aerobic counts were achieved and from 0.4 up to 1.2 log N for Enterobacteriaceae. A 3% w/w solution made from a commercially available stock solution (Glyroxyl), which consists of 44% hydrogen peroxide, 44% demineralised water and 12% glycerol proved to lower colonisation more effectively than a 2% solution.

Quality improvement of kosher chilled poultry

Pathogens like Listeria monocytogenes are of great concern in the poultry industry. Poultry, which are subjected to the kosher slaughtering and koshering process, may introduce even higher risks than conventially slaughtered poultry due to the potential for microbial cross-contamination at several critical points in the koshering line, particularly in the chillers. The effect of Microgard (MIC) and Nisin (NIS) on reducing total microbial counts, inhibiting L. monocytogenes, and prolonging shelf life was evaluated. In this work we applied dips of poultry into solutions of NIS, active against Gram-positive bacteria, and MIC, which is a bacteriocin mixture that retards growth of Gram-negative bacteria, and a mixture of organic acids. These treatments inhibited both inoculated and naturally occurring L. monocytogenes on poultry, and increased shelf life, at 6 C, from 2 to 4 d (end of shelf life was considered when total aerobic counts reached 7 log cfu/g).