THE INFLUENCE OF STUNNING PROCESSING PARAMETERS ON CHICKEN MEAT COLOUR

M.M. Ciobanu, Roxana Lazăr, Edi Piasentier, P.C. Boişteanu

Abstract
    The aim of this research was represented by the evaluation of the effects on the chicken meat colour determined by the parameters involved in the stunning process. In order to achieve the proposed goals, three experimental batches including ROSS 308 broiler chickens 42 days old, were constituted. The logistic was represented by the slaughtering technological line, allowing both the changing of the technological parameters involved in the stunning process for those three experimental batch constituted by 50 chicken/batch (L1: = 360 Hz, U = 70 V, I = 180 mA; L2: = 380 Hz, U = 85 V, I = 160 mA; L3: = 400 Hz, U = 100 V, I = 150 mA), and for the obtaining of the anatomical cutting main parts.
    The protocol aimed the measurement of three different areas for each meat specimens at a temperature of 8-10ºC with a portable Minolta spectrophotometer CM-2600d. The calibration of the chromameter apparatus was performed before each series of measurements with a calibration device Minolta CM-A32.
    With respect to the muscle region, a pronounced luminosity was observed in chest meat, followed downwards by the luminosity of the upper and lower legs. For the complementary colours red - green (a*) coordinate, the lower threshold of the calculated averages was recorded in the upper legs of the chickens coming from L1 batch (0.77±0.211 units) and in the chest muscle coming from L2 batch (0.77±0.201 units), while a maximum value was recorded for the chest muscle of the L3 batch (2.54±0.349 units).
    The variations of redness average index within a range of 1.77 units was characteristic for the muscle with a light colour; the specimens collected from the L3 chicken batch showed a slight numerical superiority for this colorimetric parameter, given the occurring of the uneven PSE flaws.

Key words: stunning, luminosity, meat colour