Psychophysics and the Sensory Assessment of Fish

Abstract

Procedures for sensory evaluation of fish often give the appearance of being empirical, that is, having been developed from practice without any contribution of underlying theory. The fundamental principles of sensory evaluation lie in psychophysics, a branch of psychology. Some textbooks of sensory evaluation have sections on psychophysics, but they are based on what might be called classical psychophysics which is summarized by the Weber/Fechner laws. Contemporary psychophysics has theories and practices which have wider applications in sensory evaluation of foods than classical psychophysics and can be applied to the advantage in the sensory analysis of fish. Three examples from the author's own experience will be presented in this discussion paper: use of the Theory of Signal Detection in evaluating taints; use of similarity ranking methods and multidimensional scaling for grouping fish by sensory properties; and application of current ideas of scaling to the measurement of freshness.

Keywords:

• discrimination methods
• freshness
• grouping
• scaling
• taints
• Theory of Signal Detection

Acknowledgments

The author gratefully acknowledges the patient and skilled tutoring of Dr. A. W. (Sandy) MacRae in principles and practices of psychophysics and his valuable contribution to the practical studies described here. Any errors in the explanation of psychophysics or in interpretations are entirely the fault of the author and cannot be blamed on Sandy.

This paper is an extended version of a presentation made at the Jette Nielsen Symposium held at The Technical University of Denmark, Lyngby, Copenhagen, on June, 18, 2010. The Symposium was held to commemorate the contribution of Jette Nielsen, who had recently retired, to the work of the Division of Seafood Research of the National Food Institute of The Technical University of Denmark especially in the field of sensory evaluation of fish and fishery products.

Notes

1. Torry Research Station was closed in 1994, though some of its function and research activities were transferred to other laboratories in Britain.