Influence of different preservation treatments on the volatile fraction of desalted cod

In the present study, desalted cod underwent a water blanching treatment and the incorporation of additives (citric acid and potassium sorbate), combined with different types of packaging (air, vacuum and modified atmosphere), to achieve an improvement of the shelf life of ready-to-use desalted cod. The purpose of this work was to evaluate the effect of these combined methods of preservation on the volatile fraction of desalted cod during 42 days in cold storage. The volatile compounds identified in all samples were those mainly related to fresh odor in whitefish, although with some exceptions. Untreated desalted cod showed a high increase of 3-methyl-1-butanol (described as a microbial spoilage index) during the storage period; a higher increase in air packaging than in vacuum and modified atmosphere packaging. The slow increase of this compound, as well as the evolution of ketones and aldehydes observed for the rest of the samples submitted to treatment, demonstrated the effectiveness of the combined treatments applied. The most efficient treatment was the combination of additives together with modified atmosphere packaging.