Impact of the pre-slaughter transport (mixing or no mixing with unfamiliar animals) of calves of As- turiana de los Valles and Retinta breeds on physicochemical and organoleptic attributes of the ageing meat. Consumers' acceptability and preference

As ageing process is one of the main factors influencing the organoleptic characteristics of meat and its consumer acceptability, the objective of this research was to study the organoleptic attributes variation of meat from Asturiana de los Valles and Retinta breeds at two times of the ageing process (7 and 14 days) under different pre-slaughter transport conditions (mixing and non-mixing with unfamiliar animals). A descriptive sensory analysis was carried out with a trained panel and the acceptability and preference for ageing meat of these two breeds were analysed with 75 consumers, as well as a study on the factors that influence the purchase decision to this type of meat. The breed and mixing with unfamiliar animals before slaughter affected significantly at instrumental tenderness. The intensity of the attributes related to the texture showed significant differences among studied samples at 7 days of ageing, with an increase in tenderness, juiciness and fibrousness while at 14 days of ageing, odour, beef flavour, liver flavour and smoothness also showed significant differences. The results indicated that the organoleptic attributes changed in intensity during ageing time, therefore, we can conclude that the attributes of tenderness, juiciness, smoothness, fibrousness, odour, beef flavour and liver flavour showed significant differences among samples and could be considered sensory indicators of ageing. The type of pre-slaughter transport (with or without mixing with unknown animals) also influenced the intensity of the sensory attributes, but less markedly than the breed effect. It was also observed that consumers prefer the meat of the Asturiana de los Valles breed aged for 14 days, despite among the factors that most influence the meat purchase decision, the ageing time was not present. Regarding purchasing habits, a relationship was observed between the meat purchase format and sale point. Overall, it is necessary to promote greater knowledge among consumers about the importance of ageing in beef quality.