Table 1.
Quality index (QI) method for assessing freshness of gutted trout packaged in a vacuum or modified atmosphere.
| Quality Attributes | Parameter | Score | |
|---|---|---|---|
| Eyes | Pupils | Black, bright with metallic radiancy | 0 |
| Black dull | 1 | ||
| Opaque grey | 2 | ||
| Shape | Convex | 0 | |
| Flat | 1 | ||
| Concave in the centre | 2 | ||
| Flesh | Color | Light rosy, smooth, shining | 0 |
| Velvety, waxy, dull, slightly changed | 1 | ||
| Slightly opaque | 2 | ||
| Opaque | 3 | ||
| Consistency | Firm and elastic, smooth surface | 0 | |
| Less elastic | 1 | ||
| Less elastic, slightly soft, dull surface | 2 | ||
| Soft, inclining to mealy | 3 | ||
| Skin | Color | Bright, pearly shine all over the body | 0 |
| Less pearly shine | 1 | ||
| Yellowish predominantly on the abdomen | 2 | ||
| Mucus | Aqueous, transparent | 0 | |
| Slightly cloudy, milky | 1 | ||
| Yellowish, opaque | 2 | ||
| Odor | Fresh, neutral, typical of fish | 0 | |
| Metallic, on cucumber, on hay | 1 | ||
| Rancid | 2 | ||
| Unpleasant (rancid and rotten) | 3 | ||
| Texture | Firm, elastic | 0 | |
| Finger mark disappears rapidly | 1 | ||
| Soft, finger mark delays disappear | 2 | ||
| Abdomen | Odor | Fresh, neutral | 0 |
| On cucumber, on melon | 1 | ||
| Rancid, on fermentation | 2 | ||
| Putrid | 3 | ||
| Total QI score | 0–22 |