The process by which man accepts or rejects food is of a multi-dimensional nature. In complex food matrices, it is not always easy to establish relationships between the individual chemical stimuli concentration, physiological perception, and consumer reaction. Consumers' responses to food are not only based on the sensory characteristics of the product and on their physiological status but they are also related to other factors, such as previous information acquired about the product, their past experience, and their attitudes and beliefs. This paper discusses different methods to obtain information about consumer perceptions, attitudes, beliefs, and expectations.