## 3 Results
### Colour  
Following an assessment of the equality of error variances [L*: F(5,114) = 2.962, \(p\) = 0.015; a*: F(5,114) = 2.792, \(p\) = 0.020; b*: F(5,114) = 6.389, \(p\) < 0.001; h(ab): F(5,114) = 5.165, \(p\) < 0.001] and the normality of residuals [L*: W(120) = 0.984, \(p\) = 0.184; a*: W(120) = 0.974, \(p\) = 0.021; b*: W(120) = 0.934, \(p\) < 0.001; h(ab): W(120) = 0.968, \(p\) = 0.005], a MANOVA was conducted. The unexplained variance analysis indicated that both meat type and treatment had significant effects. However, the type of meat--and by extension, the fat content--was not a determining factor [[PERSON] lambda = 0.617, F(4,111) = 28.221, \(p\) < 0.001]. The treatment effect on colour was found to be substantial [Wilks' lambda = 0.277, F(8,224) = 24.969, \(p\) < 0.001]. The interaction between the two factors was also significant [Wilks' lambda = 0.499, F(8,224) = 11.538, \(p\) < 0.001]. However, given that [PERSON] lambda was just below 0.5, it cannot be definitively concluded that the interaction between the factors provides a strong explanation for the variation in sample colour. Therefore, in terms of colour, the meat type emerged as the most significant explanatory variable for the dependent measures. This observation is understandable, as the colour of fatty tissue in meat differs from that of the muscle tissue itself. This principle is employed in methods for measuring the fat content of minced meat using a simple optical sensor, without the need for analytical measurements. In terms of the treatment's effect, significant differences were observed based on the Tukey post hoc test (\(p\) = 0.05). The meat samples crusted after cooking were, on average, 14% darker and 33% redder than the other samples. Conversely, the meat samples crusted before cooking were 16.5% more yellow than the others. The hue angle results for samples crusted after cooking were, on average, 17% lower than those for the other samples. The hue angle values for all samples were within the range of 0-90\({}^{\circ}\), centred around 66\({}^{\circ}\), which corresponds to an orange colour. However, with lower lightness scores, this indicates a brownish colour. A similar colour has also been described as golden brown [16]. This result can be easily explained by the fact that the surface of the meat undergoes browning during the process of crust formation. The increase in the yellow colour factor for samples crusted before cooking may be attributed to the browning of the meat surface prior to cooking, which faded during the cooking process. An interesting observation was that although meat type was a stronger determinant of meat colour than treatment, no significant differences were observed in the lightness factor or hue angle. Nevertheless, the colour of collar samples, which had a higher fat content, was 12% less red and 18% less yellow than that of the leaner tenderloin samples. In a previous experiment, there was also a decrease in the lightness and an increase in the redness of grilled (cured) meats compared to cooked and sous-vide treated meats [31]. The denatured globin hemochrome caused the red colour, and the denatured globin hemichrome caused the darker brown/tan/grey colour. This red and brown/tan/grey colour intensifies as the final temperature of the heat treatment increases [31; 32]. In our study, the crust creation temperature was much higher than the cooking temperature. This explains the difference between the \"without crust\" and \"crust after cooking\" sample groups. However, samples that were crusted before cooking had lost the substances from the surface that were responsible for the discoloration during cooking, so the same trend was not observed. The color factor results are shown in Figures 5-7 and the Hue angle results in Figure 8.  
Figure 5: Lightness (L*) [-] results of sample groups made from different meat cuts with different fat contents (tenderloin—dry; collar—fatty) with different treatments (control without crust, crust formed before cooking, crust formed after cooking).