## 3 Results and Discussion  
### Chemical Composition  
In relation to the chemical composition of the _Biceps femoris_ muscle, the results are shown as a percentage in Table 1. As we can see, the diet significantly (\(P\) \(<\) 0.05) affected the fat content in all thermal treatments. Moreover, CF pigs presented a higher (\(P\) \(<\) 0.05) amount of ash in roasted samples and a higher (\(P\) \(<\) 0.05) content of moisture in fried and microwaved samples than in CH. Regarding the fat and moisture content, the results reported in our research are in accordance with those stated by [PERSON] et al. (2014), who determined that an increase in the ration of chestnut in the pig's diet favoured the accumulation of intramuscular fat to the detriment of moisture content. The observed increase in intramuscular fat could be due to the higher energy/protein ratio of chestnuts (65.6; data not shown) in comparison with this ratio in compound feed (29.8; data not shown), which promotes an increase in fat deposition during fattening of pigs (2014). However, other studies showed that the inclusion of chestnuts did not significantly affect the muscle composition of pigs, although it did always increase the fat content in a non-significant way (2014). With respect to the protein percentage, it was not significantly affected by the finishing diet. Meanwhile, for the ash content, a higher value (\(P<0.05\)) was obtained in CF pigs only in roasted samples, while the other samples did not show differences. Generally speaking, the inclusion of the chestnut significantly increases the fat content, while its influence on the other parameters was not as clear, depending on the cooking method. Thus, a limited influence of diet in the chemical composition of the _Biceps femoris_ muscle was observed in the present research. These finding agree with those reported by [PERSON] et al. (2017), who reported that the chemical composition of the _Longissimus dorsi_ and _Sentimembranosus_ muscles of Celta pigs was not influenced by the inclusion of chestnut in the pig diet. On the other hand, as a result of the different cooking methods, chemical composition parameters were significantly (\(P<0.05\)) affected. In CH pigs, moisture (\(P<0.01\)), protein (\(P<0.01\)) and ash (\(P<0.001\)), ns: no significant difference. T: significantly different values as influenced by cooking method; * (\(P<0.05\)); ** (\(P<0.01\)); *** (\(P<0.001\)); ns: no significant difference. FxT: interaction of feeding and cooking method; * (\(P<0.05\)); ** (\(P<0.01\)); *** (\(P<0.001\)); ns: no significant difference. *\({}^{\infty}\) Means within the same row not followed by the same letter differ significantly (influence of cooking method) (\(P<0.05\)). On the other hand, as a result of the different cooking methods, chemical composition parameters were significantly (\(P<0.05\)) affected. In CH pigs, moisture (\(P<0.01\)), protein (\(P<0.01\)) and ash (\(P<0.001\)) amounts were affected by the cooking treatment, while in the CF pigs, the contents of fat (\(P<0.01\)), protein (\(P<0.05\)) and ash (\(P<0.05\)) varied among the treatments. As occurs in CH samples, [PERSON] et al. (2017) also found that the different cooking methods did not significantly affect the intramuscular fat content. However, as commented above, the fat percentage of slices from CF pigs was affected by heat treatment. This fact, although disagreeing with that obtained with [PERSON] et al. (2017), coincides with the results achieved by [PERSON] et al. (2017), who also determined the existence of significant differences in the concentration of fat after applying different cooking methods. More specifically, in our case, grilled and roasted treatments showed the lowest fat in CF pig samples (2.67%). Meanwhile, the fried method obtained the highest fat values (4.07% for CF pig muscle). The increase in fat undergone during frying may occur as a consequence of the incorporation of lipids from the frying oil itself used into the meat, as seen in previous works (2017). The trend in