*2.4. Analysis*

The proximate composition of the thigh and breast was determined according to the chemical methods specified by AOAC [16]. Dry matter (ISO 6496/2001) and Ash (ISO 2171/2010) were determined by gravimetric method, crude protein (ISO 5983-2/2009) was analyzed by Kjeldahl method, and ether extractives were performed by extraction in organic solvents (SR ISO 6492/2001).

Chicken thigh and breast color analyses were performed using a Konica Minolta CR-400 (Tokyo, Japan) colorimeter and the CIELAB trichromatic system, which determines lightness (L\*), saturation index in green/red (a\*), and saturation index in blue/yellow (b\*) values. The analyses were performed according to the method described by Panaite [17] and Vlaicu et al. [18]. Each analysis was performed in triplicate to obtain an average colorimetric value.

Firmness was determined by a Warner–Bratzler shear test using a Perten TVT 6700 texturometer (Perten Instruments, Hägersten, Sweden). The principle of this test is the measurement of the force expressed in Newtons (N) necessary to shear a piece of meat. Sample cuts (three rectangular slices/group with 2.0 cm long × 1.0 cm wide × 1.0 cm high) were made parallel to the direction of the muscle fibers. Firmness was calculated from the maximum point of the curve obtained from the test.

The texture profile analyses (TPA) were performed by a double cycle compression using a Perten TVT 6700 texturometer (Perten Instruments, Hägersten, Sweden), equipped with a Compression Platen cell. Four portions of cylindrical form (15 mm high and 20 mm wide) were cut out from each meat sample. The double compression cycle test was applied using an aluminum cylinder probe of 20 mm diameter and was performed up to 50% compression of the original portion height previously prepared. The variables analyzed were: hardness, which is the maximum force needed to compress the sample; springiness, which represents the ability of a sample to recover to its original form after removal of the compressing force; resilience, which is the ratio of the negative force input to positive force input during the first compression; cohesiveness, which is a ratio between the total energy required for the first and second compression; and gumminess, which is defined as the product of springiness, hardness, cohesiveness. Each analysis was carried out in triplicate.

The pH values of the thigh and breast samples were measured 24 h postmortem according to SR ISO 2917: 2007 using a Hach HQ30d pH-meter (Hach Company, Loveland, CO, USA). An aqueous homogenate (meat: distillated water, 1:1) was prepared and filtered according to the method described by Turcu et al. [19]. The measurements were performed in triplicate.

Principal component analysis (PCA) was performed with the proximate compositions and color and textural parameters of meat using Graph-Pad Prism v. 9.02 (San Diego, CA, USA) software package for Windows. Principal Component Analysis (PCA) was applied to assess the relationships between meat characteristics. The similarities and differences between measured variables can be seen in the loading plot. Close variables sugges<sup>t</sup> direct correlations, whereas the opposed variables indicate indirect relationships between them.

#### *2.5. Sensory Analysis of Meat*

Consumer acceptance tests were performed at the Faculty of Food Engineering, "S, tefan cel Mare" University of Suceava. An acceptance test with hedonic scale was used for the sensorial evaluation, using a 5-point scale (5 = extremely like and 1 = extremely dislike). The raw breast and thigh meat (n = 6 samples/group) were rated for sensory attributes by a semi-trained panel of 13 members selected from the University community. The study was conducted at room temperature of 22 ◦C under normal daylight. The samples were evaluated for muscle fiber appearance, appearance and characteristics of fat, flavor, firmness, juiciness, and tenderness.
