Soft scald induced damage of chicken skin

Decisive role of structure in food microbial colonization and implications for predictive microbiology

Predictive models must consider the significant effect of the physical structure of the food on the magnitude and type of microbial growth. Before such models are developed, a thorough characterization of the food structure is mandatory because this information will determine the modeling approach. In this work, several physical structures common in poultry products were classified and described. Chicken breast skin and flesh and minced breasts were examined by scanning electron microscopy and compared with a meat-based model food. Such systems were surface or internally inoculated with Listeria innocua and incubated at 25 degrees C for 24 h. Different structures, including several substructures, found in the studied systems affected microbial distribution and growth. Based on these experimental findings, the most suitable type of model for each physical structure was determined. This information provides further clarification for predictive microbiology models.

Identification of a starting point of breast skin tears during chicken plucking

A site (STP) was identified on the skin of the chicken, during defeathering in the slaughter house, at which about 90% of breast skin tears started. This site is on the ventral side of the pectoral tract area. There was no difference in location of this site with respect to different commercial lines, sexes, flocks, or time of the day. In order to demonstrate the importance of a small skin tear to ultimate damage, defeathered chickens with a minor tear at a particular site and undamaged defeathered chickens were passed through the defeathering machine a second time. Thirty-six percent of the STP chickens were torn further, but only a small percentage (about 4%) of the undamaged chickens were harmed.

Skin tearing in broilers in relation to skin collagen: effect of sex, strain, and diet

The relationship between skin tearing and collagen in broilers was investigated in two trials in which strain and sex, and strain and diet served as factorial-arranged variables, respectively. In the first trial, males and females of three strains were examined. Both skin tearing and skin collagen were significantly influenced by strain and sex without any significant strain by sex interaction. Skin collagen, expressed as a fraction of fresh skin protein (N x 6.25) was lower and skin tearing was higher in females than in males, particularly in the most susceptible strain. In the second trial, the effects of supplementary protein or methionine and of a low-density diet were tested in females of two strains that differed in their susceptibility to skin tearing. High dietary protein reduced skin tearing and increased skin collagen. The significant diet by strain interaction resulted from the more pronounced response of the susceptible strain. Neither supplementary methionine nor feeding of low-dietary-density diet significantly affected skin tearing or skin collagen.