Color measurements were performed with a Chroma Meter CR-200
colorimeter (Minolta Co., Osaka, Japan) using a 10mmport size, illuminant
D65 and a 10° standard observer. The instrument was calibrated
with black and white reference tiles and a D65 illuminant source before
the measurements. For zero calibration the black reference was positioned
to prevent light from entering the optic bundle. The observer
viewed a test sample against a multi-colored background on the left
side of the screen for each sample separately to prevent interference
from spatial inhomogeneity (Bramwell & Hurlbert, 1996). As described
by AMSA guidelines (2012), samples with 12 to 15 mm thickness are
sufficient to absorb non-reflected light. Therefore, all sausages (frankfurter,
meat-free sausage and beef ham) were peeled and sliced by
electric slicer into 15 mm-thick pieces (approximately 22 g). For each
treatment, five cylindrical samples (30 mm diameter) were longitudinally
cut and carefully cored to analyze internal color of sausages.