Rose Martinez-Dawson

The characterization and incidence of pale, soft, and exudative broiler meat in a commercial processing plant

Pale, soft, exudative (PSE) turkey meat is a growing problem for the industry of further processed poultry meat. The low pH condition due to rapid glycolysis while the body temperature is still high leads to protein denaturation, causing pale color and reduced water-holding capacity. This condition impacts product yield and quality. These studies were designed to estimate the incidence of PSE broiler meat in a commercial plant and to use response surface methodology to characterize the relationship between pH and lightness (at deboning and at 24 h postmortem), expressible moisture, drip loss, and cook loss. Pale fillets had significantly lower pH, greater L* values at 3 and 24 h postmortem, and higher expressible moisture, drip loss, and cook loss. The lower water-holding capacity of the pale fillets was characteristic of PSE meat. Additionally, L* values were measured on 3,554 boneless broiler breast fillets in a commercial processing line. By using the L* value range (>54) from the pale group of fillets as an indication of paleness, approximately 47% of the 3,554 fillets were pale and could potentially exhibit poor water-holding capacity. These results may not represent the entire industry but indicate that PSE chicken can represent a substantial proportion of commercially processed broiler meat.

Effect of combining nisin with modified atmosphere packaging on inhibition of Listeria monocytogenes in ready-to-eat turkey bologna

ABSTRACT The objective of this study was to evaluate the effect of nisin in combination with different types of packaging on the survival of Listeria monocytogenes in ready-to-eat low-fat turkey bologna. Bologna was inoculated with L. monocytogenes exposed to 1 of 6 treatments: 3 packaging treatments (100% CO2, air, vacuum), each with and without nisin. Bologna was refrigerated and sampled 9 times over 42 d. Nisin reduced initial L. monocytogenes populations by 1.5 to 2 log cycles and 100% CO2 packaging prevented outgrowth throughout 42 d of storage, whereas non-CO2 packaging displayed a 2-log increase in population during storage. Nisin (500 IU/mL) combined with 100% CO2 was effective in reducing Listeria and preventing outgrowth on bologna over 42 d of refrigerated storage.

Bacterial transfer to beverages during drinking games: ‘beer pong’

The study’s first phase identified bacteria recovered from ping pong balls used in games played by the general public. Ping pong balls were collected from uncontrolled environments and analysed according to playing location. Results showed that the highest levels of contamination were observed in games played outside, with a mean of 5.3 log CFU/ball, while the lowest levels were observed for games played over carpeted surfaces, with a mean of 2.8 log CFU/ball. In terms of identification, four distinct bacterial types were selected for presumptive identification based on their appearance on agar plates. The second part of the study examined bacterial transfer from inoculated ping pong balls to beer. Using a non-pathogenic E. coli strain as the inoculum, the mean level of contamination was 4.9 log CFU/ball. Overall, the results for both parts of this study demonstrate that the game of beer pong is a source of bacterial transfer.