## 1 Introduction  
Cheese flavor is one of the most important quality factors and consumer acceptance criteria [1]. Monitoring and ensuring that cheeses have good and specific quality is a challenge for dairy companies and producers. However, during cheese elaboration, several parameters could influence its flavor, such as cheese-making practices, know-how and the raw milk material used.  
Protected Designation of Origin (PDO) cheeses stand out for their strict specifications, particularly concerning the conditions of milk production and its origin, thus establishing a link with regional specificities. Salers and Cantal are two iconic PDO French semi-hard cheeses, with an approximate weight of 40 kg, produced in the Auvergne Rhone-Alpes region at annual amounts of 1076 T and 11,448 T, respectively. The cheese-making processes of the two PDO cheeses are very close, but the big difference concerns the use of milk which can be pasteurized and that is not subjected to a specific harvest period of the year for Cantal compared to Salers cheeses. Salers is an artisanal cheese made exclusively with raw cow's milk curdled in a specific wooden vessel called \"Gerle\". It has the particularity of being produced during a specific period of the year: from 15 th April to 15 th November. Different cow breeds can be chosen to obtain the milk for this kind of cheese-making, but when only milk from the Massif Central breed of cows, also called \"_Salers_\", is used in its fabrication, the cheeses obtained are then called \"Salers Tradition\" [2; 3]. The ripening time for PDO Salers cheeses varies from a minimum of three months to two years. In contrast, PDO Cantal cheeses can be made with _Salers_ milk or with milk originating from other cow breeds such as _Prim'Holstein_, _Aubrac_ or _Montbeliarde_ breeds. For Cantal cheese, the minimum ripening time is one month to over twelve months.  
Sensory differences can be perceived in the flavor and texture between each cheese's category. In general, the flavor profile is determined by different volatile compounds included in cheese matrices. During the ripening time, different biochemical processes lead to the synthesis of volatile compounds belonging to different chemical families, such as ketones, esters, alcohols, acids, aldehydes and terpenes [4; 5]. Depending on the type of cheese, the quality and the quantity (concentration) of these volatile compounds vary. The ripening time is not the only factor involved in flavor development. Indeed, numerous studies have shown that other factors, such as the extent of milk production (feeding diets and breed), milk characteristics (raw milk, heating treatment, milk microflora and milk composition) and the diversity in cheese-making practices, could have an impact on the development of flavor in cheese [6; 7; 8; 9; 10]. In reality, professionals of the supply chain think that there is an evolution of the flavors between Cantal and Salers cheeses due to the origin of the milk (Salers or other cow breed) after a long ripening time. However, this is just an observation. To date, no study has shown the differences between these two types of cheese depending on the origin of the milk. Several studies were conducted specifically on these types of cheese (Cantal or Salers, but separately), covering various topics such as microbiological aspects, the characterization of cheese texture and the aromatic profiles [6; 11; 12; 13]; however, to date, the sensory and biochemical differentiations between these two categories of cheese have not been studied.  
The aims of this exploratory study are to sensorially and chemically characterize the two categories of PDO cheeses at an advanced ripening period (>8 months) and to evaluate the differences that could come from those two categories of cheese (Cantal vs. Salers) and evaluate the differences in cheeses coming from different cow breeds (_Salers_ vs. _non-Salers_).