46G-21 |
Color characteristics of chicken thigh meat using visible reflectance spectra |
S. KARTIKA1, L. W. Grimes2, and J. C. Acton1. (1) Department of Food Science and Human Nutrition, Clemson University, P.O. Box 340371, Clemson, SC 29634-0371, (2) Department of Experimental Statistics, Clemson University, F-148 Poole Agricultural Center, Clemson, SC 29634 Discrimination of meat color is subject to the balance among three pigment forms, myoglobin (Mb), oxymyoglobin (OxyMb) and metmyoglobin (MetMb). Reflectance spectra have been used extensively to characterize the distribution of meat pigments. However, spectral evaluation of color change in ground poultry meat has been limited. Our objective was to evaluate reflectance spectra and determine the percent of pigment forms for ground chicken thigh meat packaged in two types of films with two types of meat treatments, "fresh" versus "frozen-thawed." Fresh and frozen-thawed chicken thighs were skinned, deboned, and trimmed of fat and connective tissues. The boneless meat was then ground and vacuum packaged using oxygen barrier (16 cc/m2/24hr at 23°C, 0% RH, 1 atm) and non-barrier (13,800 cc/m2/24hr) films. Reflectance measurement was conducted at 2-day intervals over 12 days of light (970 lux) display. The K/S spectral curve of ground thigh meat packaged in non-barrier film shifted from mainly OxyMb on days 0-8 to OxyMb with considerable Mb at day 12. Meat packaged in barrier film remained predominantly Mb. Meat treatment had no effect (p>0.05) on pigment distribution although there was a change (p<0.001) in distribution over 12 days of display. Overall, the % MetMb remained fairly constant except for frozen-thawed meat packaged in non-barrier film. Meat packaged in barrier film showed decreases (p<0.001) in lightness (CIE L*) and chroma (CIE C*) in comparison to meat in non-barrier film. Film type had no effect (p>0.05) on hue (CIE h). The % Mb, % OxyMb, and % MetMb were correlated (p<0.001) with K/S (474/525), K/S (610/525) and K/S (572/525), respectively. The results suggest that, in comparison to red meat such as beef, the color of ground chicken thigh meat may not be discriminated against due to the occurrence of MetMb, but rather to the presence of Mb with OxyMb.
Session 46G, Muscle Foods I
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