Standardization Of Measurement On Edible Quality Of Chilled Chicken

Edible quality was the dominant characteristic of the commodity value of poultry, but we hadn’t a standardized measurement on edible quality yet and less research on it was reported. The aim of this study was to investigate the effects of different conditions and pretreatment on instrumental methods of chicken breast color, Warner-Braztler shear force and water-holding capacity and discuss the correlation among the qualities including color, pH24h and water-holding capacity. The goal of this study was to provide a theoretical basis to harmonize instrumental methods on edible quality of chilled chicken breast. The experiment is divided into three parts:Part 1:The detailed test condition and pretreatment methods included measuring position (dorsal part orventral part), illumination intensity (60,200,600lux), background color (red, white and black), blooming time (15,30,45,60min) and blooming temperature (0-4,10,25 ℃). The results showed:Different measuring position had significant effects on LAB value (P<0.05); Light intensity did not affect the results; Background only had significant effects on thinner position(P<0.05), while it had no significant effects on thick part. In the temperature of 10℃ and 25 ℃ blooming time had no effect on breast color, while in the temperature of 0～4℃ L* value significantly decreased with the increasing of blooming time (P<0.05). This phenomenon had some relation to the condition of refrigeration. CV (coefficient of variabiliy) of color data from the blooming of 30min was minimum. In conclusion, choosing dorsal part and the centel part (on third of the whole breast) as the measuring position was better; blooming temperature was stable and nomarl indoor temperature (25 ℃); 30min of blooming time was the best; the best choice of background color and illumination intensity were the common parameters of white and 600/ux.Part 2:The effects of different sample pretreatment methods and conditions (including internal temperature, water-bath temperature, holding time, chilling temperature and intruments) on the shear force of poultry breast muscle was studied in this part. The results showed the effects of internal temperature, water-bath temperature, holding time, chilling temperature and different instruments had significant effects on that breast Warner-Bratzler shear force (WBSF) and cooking loss which increased with the increasing of internal temperature, water-bath temperature and holding time. Under the condition of holding temperature in 75 ℃ and internal temperature in 70℃, the value of Warner-Bratzler shear force was the most stable and its variable coefficient was smallest. The value (including Warner-Bratzler shear force and cooking loss) under above condition of temperature could reflect better the transformation of meat during cooking. Breast samples compared to the temperature of 10 ℃ chilled to a temperature between 0℃and 4℃ showed the smaller value of Warner-Bratzler shear force, cooking loss and the lower coefficient of variation. In conclusion, the results suggested that the following conditions for measuring chicken Warner-Bratzler shear force were heating in a 75 ℃ water bath to an internal temperature of 70 ℃ and then immediately storage at 0～4℃ overnight.Part 3:The effects of different pretreatment methods on measuring water-holding capacity (WHC) expressed as drip loss, pressure loss and cooking loss were studied in this part. The correlation among meat color, shear force, pH24h and different indicators of WHC was analyzed. The results showed:The differences among the dripping time from 24 to72h which influenced drip loss were significant (P<0.05). Pressure (from 25 to 40kg) and holding time (3 to7min) had a significantly impact on pressure loss (P<0.05). The cooking loss is increased with the increasing of internal temperature (from 65 to 75℃) and water-bath temperature (from 70 to 80℃). In conclusion, the results suggested that the following conditions for measuring the dripping loss was the size of cut in 2×2×2 cm with the dripping time of 48h, the pressure loss were the pressure of 35kg with holding time of 5min and the cooking loss were heating in a 75 ℃ water bath to an internal temperature of 70℃. The results about correlation showed:The shear force had strong positive correlation with cooking loss (P<0.05). There was negative correlation between the value of L* and pH24h (P<0.01). Drip loss had significant correlation with other parameters of WHC (including pressure loss, immobilized water and so on). In sum, pH24h had some relation with meet color and WHC in a certain extent; dripping loss was the best index for measuring the WHC.