30C-8 |
Texture and microstructure of irradiated chicken breast |
K. S. YOON, Department of Human Ecology, University of Maryland Eastern Shore, 2103 Trigg Hall, Backbone Road, Princess Anne, MD 21853 Food irradiation is being considered as an important tool, not only in ensuring the safety but also in extending shelf life of fresh meats because of its effectiveness in eliminating pathogens without deteriorating product quality. While numerous studies showed the effectiveness of irradiation on pathogenic microorganisms, not enough empirical work has been done on the effect of irradiation on the quality attributes, especially texture and microstructure of poultry meat. The objective of this study was to evaluate the effects of irradiation on the textural and microstructural properties of chicken breasts during refrigerated storage. Fresh, raw chicken breasts were irradiated using a 60cobalt sources at delivered, observed doses from 2.2 to 2.9 kGy and cooked at 350ºC for 20 min. Shear force and cooking loss were measured at 2-day intervals for a 14-day refrigerated storage period. Also, the microstructure change of chicken breast due to irradiation was evaluated using transmission electron microscopy. Irradiated chicken breast had significantly more cooking loss and greater shear force than unirradiated sample. Shear force of irradiated chicken breast was significantly higher than that of the controlled unirradiated sample: 11,807 g and 6,814 g, respectively. Transmission electron microscopy revealed distinct differences in size of myofibril units (sarcomeres) between irradiated and unirradiated chicken breast. Contractions in length, width, and disruption of myofibrils in irradiated breast meat were noticed compared to control, which exhibited no structural damage. This study demonstrates clearly that irradiation causes contraction of myofibrils, thus leading to textural toughening of chicken breast. Further intervention studies are needed to control the textural toughening problem of irradiated chicken breast, since USDA has officially approved irradiation to improve microbial quality of chicken carcasses.
Session 30C, Muscle Foods: Tenderness, Quality, Processing, Marination, Oxidation, and Shelf-Life
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