###### Abstract  
The aim of this study was to evaluate the influence of the diet (chestnut vs. commercial feed) and cooking techniques (roasting, grilling, frying and microwaving) on the quality of the _Biceps femoris_ muscle of the Celta pig breed. Chemical composition, physicochemical parameters, oxidative stability and volatile profile were analysed. Overall, the inclusion of chestnuts did not affect the chemical composition, except for intramuscular fat content, which was higher in chestnut-fed pigs. The colour and shear force of cooked _Biceps femoris_ were not affected by the finishing diet. However, a significant increase in cooking losses and thiobarbituric acid reactive substances (TBARS) value was found with the chestnuts included in the diet. In addition, the inclusion of chestnuts also modified some volatile compound that could be associated with the diet, such as furan, 2-pentyl. On the other hand, the cooking method significantly affected chemical composition (moisture, fat, protein and ash content), colour parameters, cooking loss, TBARS and volatile profile, whereas the shear force was not affected. Concretely, fried and microwave were the techniques that led to a greater presence of intramuscular fat. In addition, the frying method also showed the highest a* value, whereas the microwaved technique displayed the highest cooking loss. Regarding lipid oxidation, the fried method displayed the lower TBARS and hexanal content. On the other hand, the major volatile compounds were aldehydes in all cooking methods except for the frying technique in chestnut samples. Finally, method-frying displayed the lowest amount of total volatiles compounds, unlike grilling. chestnut diet; cooking techniques; colour parameters; cooking loss; shear force; lipid oxidation; volatile compounds; Celta pig breed +
Footnote †: journal: _Biology of Medicine_  
0000-0001-5000-0000-00001-5000-00001-50000-00001-50000-00001-50000-00001-500001-500001-500001-50001-50001-500001-50001-50001-50001-50001-50001-50001-50001-5  
autochthonous genetic types, fattened in extensive livestock systems has incremented [1]. This is the case of the Celta pig breed, which is a native pig of Galicia (north-west Spain) that is highly valued due to its succulent meat and its intense fat infiltration into lean meat [2]. Furthermore, the Celta pigs are traditionally reared in an extensive or semi-extensive production system using natural resources, such as acorns, chestnut and vegetables. Specifically, one of the most widely used products to fatten this pig is chestnut because it is a great source of carbohydrate [3]. Concretely, these fruits are suitable nonwithstanding for maintaining and rearing adult animals. Moreover, chestnuts are a good source of antioxidants [4] and unsaturated fatty acids [5]. However, chestnut fruits are underused, for instance, the smaller-sized chestnuts and the by-products occasion in the industry. In this area, this livestock feed could be appropriate to obtain high-quality products differentiated by their healthier fat [6] and by their natural endogenous antioxidants. Furthermore, the use of chestnut could also support to reduce the current costs derived from the high prices of commercial concentrates in pig farming [7; 8]. On the other hand, the cooking of meat is necessary due to the fact that it becomes edible and more digestible. Besides, cooking causes other positive and negative effects on meat [9] that could influence consumer acceptance. In view of these developments, it is important to understand the events that take place during the heat treatment of meat. Thus, lipid oxidation and Maillard reactions take special interest because they are important mechanisms for the development of odour, flavour and colour in cooked meat [10]. Regarding nutritional value, cooking changes the chemical composition of meat [11]. This process may cause nutritional losses such as thermolabile vitamins, and it may produce several toxic compounds like heterocyclic amines and cholesterol oxidation products (COPs) [9].