As far as the cooking effect on L*

As far as the cooking effect on L* values, the prolonged sous-vide treatment
might have led to amore intense protein denaturation and aggregation,
despite the fact that roasted samples were cooked to final higher
temperatures, but for a much shorter time. In turn, this higher protein
denaturation would increase light scattering
Similarly, the higher a* values in oven roasted samples were most
likely due a consequence of a lower degree of denatured myoglobin in
this samples. Such process is temperature dependent, starting at 55 °C
and continuing till 80 °C (King & Whyte, 2006), but it also depends on
the time subjected to a certain temperature (Roldán et al., 2013).
Injection of a brining solution with phosphates showed a variable
effect on the yellowness of cooked lamb meat samples. In fact, even
though the ANOVA showed a significant effect due to phosphate
injection, the only group detected as different (p b 0.05) by the
Tukey's test was that of the lamb loins with 0.2% of added phosphate,
while lamb loins with no added phosphate or with 0.4% of added
phosphates showed higher levels for this variable. Nevertheless, detected
differences for the b* color parameter could be considered negligible.
Other authors have pointed out no effect on this parameter (Önenc
et al., 2004) or a slight increase in yellowness (Villamonte, Simonin,
Duranton, Chéret, & de Lamballerie, 2014).