Hue angle is the angle for a point calculated from a* and b*
coordinates in the color space. Chroma is the quantitative component
of the color, which reflected the purity of color in the CIELAB
space. Texture measurements in form of texture profile analysis
(TPA) (Bourne, 1978), of the breadcrumbs was performed by a
Texture Analyzer CT3 (Brookfield, Middleboro, USA). A bread slice
of 1 cm thickness was compressed up to 50% of its original height at
a crosshead speed of 1 mm/s with a cylindrical acrylic probe
(diameter 25.4 mm). From the TPA curves, the following texture
parameters were measured: hardness (N), springiness, cohesiveness,
resilience and chewiness (N). Hardness was defined by peak
force during first compression cycle. Cohesiveness was calculated
as the ratio of the area under the second curve to the area under the
first curve. Springiness was defined as a ratio of the time recorded
between the start of the second area and the second probe reversal
to the time recorded between the start of the first area and the first
probe reversal. Chewiness was obtained by multiplying hardness,
cohesiveness and springiness. Resilience was calculated as the area
during withdrawal of the penetration, divided by the area of the
first penetration.
2.7. Statistical analysis
Standarized skewness and standarized kurtosis analyses were
made to verify normal distribution of the data. Multiple sample
comparison was conducted to evaluate significant differences
among samples by analysis of variance (ANOVA) and multiple range
tests. Fisher's least significant differences (LSD) test was used to
describe means with 95% confidence (P < 0.05). Data was also
evaluated using Pearson correlation coefficients to establish relationship
among variables. Only correlation coefficients (in absolute
value) equal or greater than 0.68 were considered meaningful. All
statistical analyses were performed using Statgraphics Centurion
16 (Statistical Graphics Corporation, UK).