The relationship between broiler breast meat color and pH, moisture content, water-holding capacity (WHC), and emulsification capacity (EC) was investigated. In each of three replicate trials, fillets were collected from three different commercial processing plants according to breast meat lightness (L^*) values as follows: lighter than normal (light, L^* > 53), normal (48 < L^* < 53), and darker than normal (dark, L^* < 46). Color values of lightness (L^*), redness (a^*), and yellowness (b^*) were measured at 0 and 24 h after collection. Fillets were then ground and homogenized prior to determining color, pH, moisture, WHC, and EC of the ground meat. There was a significant difference among the three color groups (light, normal, and dark) in L^*, a^*, pH, WHC, and EC. The L^* values of whole raw breast fillets had significant negative correlation coefficients with ground meat EC (−0.9237), pH (−0.9610), and a^* (−0.6540). Emulsification capacity had significant positive correlations with pH (0.9572) and water-holding capacity (0.7080). WHC had significant correlations with a^* (0.8143), moisture (−0.7647), and pH (0.7963). Lighter-than-normal meat was associated with low pH, high moisture, low EC, and low WHC. These results indicate that wide differences in raw breast meat color exist and that these differences may be used by poultry further processors as an indicator of fillets with altered functional properties.

A total of three experiments were conducted to compare physical and microbiological properties of raw and marinated broiler breast fillets selected as being either lighter or darker than normal. Visibly light- and dark-colored breast fillets were divided into marinated and control groups, and vacuum-tumbled for 20 min at 4 C under 80 kPa pressure. Breast fillets from the four treatment groups were evaluated for shear values, raw and cooked meat pH, drip-loss, cook-loss, water-holding capacity, and 7 d psychrotrophic count. The light-colored fillets were significantly lighter, less red, and more yellow than the dark fillets. Lightness values increased when fillets were marinated. Moreover, the light fillets had a lower pH than dark fillets. The pH values of raw and cooked breast meat were related to meat color but not marination. Dark-colored fillets had significantly higher marination pick-up and a higher fraction of bound moisture and significantly lower drip and cook-loss. No differences were observed in shear values between color or marination treatments. There were no significant differences in psychrotrophic plate counts (PPC) or capacitance detection times (CDT) due to color or treatment at Day 1. After 7 d of storage at 4 C, PPC was significantly lower for marinated samples. No correlations were observed between pH and PPC, CDT, or odor. Based on these differences in physical and microbiological properties, further processors may consider separating breast fillets according to color.

A study was conducted to examine the effects of thermal preconditioning on the water-holding properties of chicken breast and leg meat. An initial experiment was performed by heat shocking (40 to 41 C for 1 h) and euthanatizing broilers at 3 to 6 wk of age. As seen commercially, heat caused higher drip loss, and the majority of this loss for breast (75 to 80%) and leg (90 to 100%) meat occurred within 3 d post-mortem. A second study with 6-wk-old broilers tested the following treatments: control (25 C), heat shock (40 to 41 C for 1 h), preconditioned control (3 consecutive d of exposure to 35 C for 3 h followed by a 21-h recovery between each exposure), and preconditioned (same as preconditioned control with an added heat shock on the final day). Thermal preconditioning did not circumvent the water-holding problems associated with heat shock. Meat from chickens exposed to heat lost significant amounts of drip during the crucial processing period--the first 6 h after death. In general, leg meat had lower drip loss and higher held water than breast, but cooked leg meat had lower held water. Treatment and meat type were significant (P < .05) in determining drip and cook loss. Preconditioned and heat shock breast meat appeared pale, soft, and exudative, similar to a condition found in pork. Thermal preconditioning does not prevent the loss in water-holding properties associated with heat.

Experiments were conducted to compare the chemical composition of broiler breast meat that was naturally lighter than normal, normal, and darker than normal. In each of three separate replicated trials (wk), fillets were obtained from three commercial processing plants. Approximately 25 fillets of each color group were selected based on International Commission on Illumination (CIE) lightness values as follows: lighter than normal (L* > 53), normal (48 < L* < 51), and darker than normal (L* < 46). The fillets from each replicate, plant, and color group were ground and mixed together, and samples for the 27 treatment groups subjected to color, pH, and chemical analyses (protein, ash, moisture, total lipids, iron, glycogen, and fatty acids profile). The whole fillets had significantly different color values for the three color groups at 0 and 24 h prior to grinding. Of the ground meat samples, there were significant treatment and plant differences in composition. There were no color treatment effects on moisture, lipid, glycogen, iron, ash, or fatty acid ratios. Meat from the light group had significantly lower protein values than the normal or dark meat and lower ash than the dark group. The light group also had significantly higher levels of C16:1 and lower levels of C18:0 and C20:4 fatty acids than the dark group. Among the three plants, there were significant effects for breast meat color and composition. Results indicated that, although plant had more effect on composition, differences by color group might indicate that extreme variation in color may be due to long-term genetic factors as well as short-term antemortem stress.

Three replicate trials were conducted to determine the effect of raw broiler breast meat color on marinated and cooked meat quality. In each trial, 90 fillets were collected from a commercial processing plant based on lightness (L*) values of breast meat as follows: light, L* > 53; normal, 48 < L* < 51; and, dark, L* < 46. For each fillet the color, pH, and weight were determined, and the fillets were marinated in three lots of 10 fillets from each color group (20% wt:wt of 5% salt and 2.5% sodium tripolyphosphate in a vacuum tumbler). Marination uptake was determined; the samples were held for 24 h at 2 C, and color, pH, and weight again were determined. Next, the samples were cooked, and the meat was subjected to color, pH, cooked yield, shear force, and moisture analyses. Results showed that absolute color values changed with marination and cooking, but that L* and pH differences by color group were maintained through marination and cooking. There were also significant differences in marinade absorption, cooked yield, and shear value, particularly among the extremes of light and dark meats. There was no significant difference in final cooked meat moisture. As expected, there were significant negative correlations between meat lightness and pH; however, raw muscle pH was not correlated to final product moisture or shear but was positively correlated to cooked meat yield and negatively correlated to marinade absorption. These results indicate that the pH variation associated with extreme raw breast meat color variation can affect breast meat marination and cooked meat quality.

A study was conducted to investigate the microbiological impact of spray washing broiler carcasses with chlorinated water (0 or 50 ppm) at different temperatures (21.1, 43.3, or 54.4 degrees C). A whole carcass rinse (WCR) was performed on each carcass before (control) and after spray washing (final). After the control WCR, carcasses were inoculated with 0.1 g of cecal material containing 2 x 10(5) cells per gram of Campylobacter and 2 x 10(5) cells per gram of nalidixic acid-resistant Salmonella. Carcasses were held at room temperature for 12 min before washing in an inside-outside bird washer (80 psi for 5 s). Chlorine level and water temperature had no effect on total aerobic bacteria, Escherichia coli, or Campylobacter numbers recovered from the final WCR. Levels of bacteria found on carcasses before and after washing were 4.6, 3.6, and 3.5 log10 cfu/mL rinse for total aerobic bacteria, E. coli, and Campylobacter, respectively. Average counts for nalidixic acid-resistant Salmonella after washing were 3.1 log10 cfu/ mL rinse irrespective of water temperature or chlorine level (P < 0.05). In addition, chlorine level and water temperature had no effect on the breast skin color, with average values of L* = 66.6; a* = -0.09; b* = -0.05 (P < 0.05). Under the conditions outlined in the present study, adding chlorine and/or elevating the water temperature during spray washing in an inside-outside bird washer did not enhance the removal of bacteria from broiler carcasses and had no effect on carcass skin color.