•Intrinsic attributes: these are the physical attributes of the product and they cannot be modified except by changing the physical characteristics of the product (Bredahl et al., 1998, Hurling and Shepherd, 2003 and Issanchou, 1996). They allow the objective measurement of quality and are specific to each product. It therefore seems clear that the intrinsic or extrinsic nature of the product depends on the relationship between physical attributes and the product: if a product changes when you change the attribute, this attribute is considered to be intrinsic, if not changed, then it is considered extrinsic.