rapid non-destructive method for fish quality control by determination of smell intensity

The ‘Cosmos’ instrument (Japan) was applied to the evaluation of fish quality in six species of different origins, by determination of smell intensity. Pond-raised fish (trout, carp, silver perch, tilapia, barramundi) were stored in ice for 4–5 weeks and frozen/thawed mackerel was kept at room temperature for 74 h. The fish quality was examined by organoleptic assessment, by determination of smell intensity and by tests of the chemical (total volatile basic nitrogen, hypoxanthine and histamine) and dielectric (Torrymeter) properties. Strong correlation was found between the organoleptic and 'Cosmos' results, whereas the data from the chemical and Torrymeter analyses were relatively poorly correlated with the sensory evaluation and 'Cosmos' data. Thus the application of the 'Cosmos' instrument for objective quantitative evaluation of fresh and chilled fish quality by determination of smell intensity seems practicable. The 'Cosmos' instrument is hand-held and portable as well as being rapid and non-destructive in operation; therefore it could be used for evaluation of fresh and chilled fish in the field and on board fishing vessels.