Effects of high-energy electron irradiation of chicken meat on Salmonella and aerobic plate count

Spoilage Bacteria Counts on Broiler Meat at Different Stages of Commercial Poultry Processing Plants That Use Peracetic Acid

In poultry processing, spoilage microbes are persistent microorganisms, which affect the quality of broiler meat. Peracetic acid (PAA) is the most common antimicrobial used by commercial processing plants, which can reduce the prevalence of these microbes. The goal of this study was to determine the concentrations of aerobic bacteria, coliforms, lactic acid bacteria, and Pseudomonas on broiler meat in processing plants that use peracetic acid in various concentrations as the primary antimicrobial. Samples were collected from three processing plants at five processing steps: post-pick (defeathering), pre-chill, post-chill, mechanically deboned meat (MDM), and drumsticks. Samples were rinsed in buffered peptone water for bacteria isolation. Over six log CFU/sample of aerobic plate counts (APC), lactic acid bacteria, and coliforms were detected on post-pick samples. All spoilage bacteria were reduced to nondetectable levels on post-chill samples (p < 0.001). However, the presence of all bacteria on mechanically deboned meat (MDM) samples indicated varying degrees of cross contamination from post-chill and MDM samples. These results suggest PAA effectively reduces spoilage microbes in chilling applications irrespective of differences in PAA concentrations. However, due to the levels of spoilage microbes detected in MDM, it may be worth investigating the potential interventions for this stage of processing.

Effect of electron beam irradiation on poultry meat safety and quality

The purpose of this study was to determine the effectiveness of electron beam irradiation at doses of 1.0 and 1.8 kGy on the elimination of bacteria from boneless, skinless chicken breasts without significantly altering product quality. Microbial testing was conducted in triplicate using a whole carcass rinse method with each nonirradiated control group and an irradiation treatment group consisting of 10 samples. Results indicated that mean counts for coliforms, generic Escherichia coli, and psychrotrophs were 3.13, 3.26, and 1.92 log10 cfu/200 mL rinsate, respectively, in the control samples. However, these populations were not detected after the samples were irradiated with 1.0 or 1.8 kGy. Mean count of 4.60 log10 cfu/200 mL rinsate was detected for aerobic bacteria in the control samples. Irradiation doses of 1.0 and 1.8 kGy reduced the levels to 2.23 and 1.62 log10 cfu/200 mL rinsate, respectively. Irradiation also rendered the fillets free of Salmonella and Campylobacter. Consumer taste panels (product stored for 0, 14, and 28 d at 0 C) indicated that, at Day 0, there were no differences among controls and treatment groups for any of the quality attributes tested. At Day 14, texture and flavor attributes were lower for the irradiated groups. At Day 28, samples irradiated with 1.0 and 1.8 kGy were less desirable with decreased texture, flavor, and overall acceptability. Degree of lipid oxidation also increased as storage time and level of irradiation increased. Irradiated samples also had higher a* values, indicating they were pinker in color.

Effect of high-energy electron irradiation of chicken meat on thiobarbituric acid values, shear values, odor, and cooked yield

Experiments were conducted to determine whether electron-beam irradiation would affect shear values, yield, odor, and thiobarbituric acid (TBA) values of chicken tissues. Broiler breasts (pectoralis superficialis) and whole thighs were irradiated with an electron-beam accelerator at levels to produce adsorbed doses of 100, 200, and 300 krads on the surface of the sample. The thigh samples were stored for 2, 4, and 8 days before testing for TBA values. The depth to which the radiation had penetrated the pectoralis superficialis muscle was also determined. Radiation penetrated 22 mm into slices of pectoralis superficialis muscle when 100 krad was absorbed by the surface of the tissue. The dose absorbed beneath the tissue surface to a depth of 10 mm was larger than the dose absorbed at the surface. The absorbed dose decreased as the depth of penetration increased. For cooked breast tissue, the shear values and moisture content were not affected by the absorbed radiation. Cooking losses of aged breast tissue were not affected by irradiation, but cooking losses were reduced in breast tissue that had not been aged. Irradiating uncooked thigh and uncooked breast samples produced a characteristic odor that remained after the thighs were cooked but was not detectable after the breast samples were cooked. With two exceptions, no significantly different TBA values were found that could be attributed to irradiation.