Besides being rich in protein and monounsaturated fatty acids, mackerel is known for its numerous physiological benefits. These include improving the efficacy of medication, promoting vascular health and fortifying the immune system. It also has a high level of potassium and selenium. It contains 1 gram of omega-3 fatty acids. This may help reduce the risk of heart disease, cancer, depression and other illnesses. Moreover, the omega-3 fatty acids can lower the risk of Parkinson’s disease and Alzheimer’s disease.
The efficacy of mackerel fillets wrapped in G/PCL film with Lys and PPE was investigated. A combination of Lys and PPE significantly reduced microbial contamination and delayed oxidative changes of lipids in mackerel fillets. This also helped in prolonging the shelf life of mackerel fillets. It was also found that Lys in combination with PPE reduced the triglyceride content in mackerel fillets.
The efficacy of mackerel was assessed through sensory properties of untreated samples and samples that were treated with a combination of Lys and PPE. These samples were subsequently stored at different times. The results showed that the oxidative process of lipids was delayed by two months with the use of G/PCL film with Lys and lysozyme. Compared to the untreated samples, the lysozyme-PPE sample was effective in reducing FFA content and weight loss.
Several sensory attributes of mackerel fillets were scored from 0 to 5. The obtained pH-value was higher than the post-rigor pH reported for mackerel species. In addition, the bacteriological examination improved with the use of TVB-N. This suggests that processing of mackerel may promote the subsequent hydrolytic activity of lipid constituents. However, temperature fluctuation may have contributed to increased FFA content in mackerel fillets.
Although the sensory attributes of untreated mackerel fillets were improved, the overall quality of the fillets decreased significantly with the extended storage period. The control samples lost their acceptable quality standards on the sixth day of storage. The samples that were treated with Lys and PPE improved the quality of mackerel fillets, while those that were untreated showed no shiny colour. In addition, the VAC-S sample showed a deviation from the rancid odour and flavour of the untreated samples. The VAC-S at 8 months was closely associated with the textural attributes and the salty flavour.
In addition to improving the sensory properties of mackerel, Lys and PPE also helped in prolonging the shelf life of the fillets. This may help to promote the consumption of mackerel fish and to prevent microbial contamination. In addition, Lys and PPE reduced the FFA content and TBARS in mackerel fillets. Moreover, the G/PCL film with Lys and PCL delayed the development of rancid odour and flavour by two months.
The results also indicated that mackerel was rich in omega-3 fatty acids, but its PUFA content was lower than previous reports. This may be due to the natural variations in the feed composition and the temperature of the ocean. However, the FFA content of mackerel was still higher than the maximum recommended value of 7 log10 CFU/g in raw fish.