Manual determination of minced fish flesh in mixed fillet-minced cod blocks: collaborative study

A simple, rapid method for determining the amount of minced fish in mixed fillet-minced cod blocks was tested by 9 collaborators. Each collaborator first examined 2 practice blocks containing 20% mince, and then examined 6 blind duplicate samples of 5 lb cod blocks from each of 3 test lots containing, respectively, 26.25, 18.75, and 12.5% mince. The data from one of the 9 collaborators was not usable because of a malfunctioning scale. Standard deviations (SD) for the 3 lots (all 8 collaborators combined) were 1.77, 1.51, and 1.65, and coefficients of variation (CV) were 6.8, 8.9, and 16.2%, respectively. For comparison, the results of an informal collaborative study by 10 participants on 16.5 lb mixed cod blocks containing 20.1% mince were SD 2.72 and CV 0.136%. Collaborators reported no problems with the method, and statistical analysis shows the method to be sufficiently precise for this type of determination. The method has been adopted official first action for cod.