The Quality Index Method (QIM) is based upon objective evaluation of certain attributes of raw fish (skin, eyes, gills etc) using a points scoring system (from 0 to 3).
The scores for all the attributes are then added to give an overall sensory score, the so-called quality index. The quality index increases linearly with keeping time in ice. Therefore the total demerit score can also be used to predict the remaining shelf life. The description of the evaluation of each parameter is written in a guideline.
No excessive emphasis is laid on a single attribute so a sample cannot be rejected on the basis of a single criterion.
Minor differences in results for any one criterion do not unduly influence the total QIM score. The lower the score the fresher the fish.
Gills cod after one day ice storage
Gills cod after 15 days ice storage