| UNE | Unenzymatized chicken bones |
| ALK | Alkaline protease |
| NEU | Neutral Protease |
| PAP | Papain |
| BRO | Bromelain |
| TRY | Trypsin |
| LEU | Leucine Transaminase |
| FLA | Flavorzyme |
| COM | Composite enzyme |
| DH | Hydrolysis degree |
| TCA | Trichloroacetic acid |
| FAA | Free amino acid |
| IS | Internal standard |
| RT | Retention time |
| RI | Retention index |