Thesis:

Metabolomics Workflow for Quality Control of Differently-Processed Pre-Cooked Fish Fillets

The purpose of this research is to investigate the metabolomics workflow to control the quality of pre-cooked fish fillets with different processing. For this purpose, fresh cut fillets were procured from a reputable store. Fillets were stored at 1°C and processed with‌‌in 2 hours of slaughter. Before cooking fish fillets, after removing the skin, fresh fish fillets were placed on racks (8 fillets per rack) for cooking in a convection oven‌.Fish fillets were cooked for 13 min at 130°C and 13 min at 115°C and cooled to 1°C. Fish fillets were subjected to different treatments. Treatments or independent variables: 3 treatments including the first treatment of 5% salt. That is, for every 100 grams of fish meat, 5 grams of salt were evenly sprinkled on the surface of the fish. Second treatment: 500 mg/kg sodium ascorbate solution was prepared as a millimolar solution and sprayed on the fish pieces. Third treatment: control, fish pieces without additives. Then the samples were kept at 5 degrees Celsius for two weeks. Metabolites were measured on days 0, 7 and 14. Also, pH, acidity in terms of lactic acid, volatile nitrogen, count of lactic acid bacteria, andis peroxide, histamine, and tissue stiffness were examined qualitatively (cutting with a knife). The results of this research showed that the lactic acid values, lactic acid bacteria count, color, firmness, TVN and pH had a significant change during the storage period, while the histamine level did not change. The effect of ascorbic acid treatment‌ in preventing the increase of peroxide value was also significant. .

Keywords: Key words: metabolomics, quality, fish fillets, different processing, lactic acid, volatile nitrogen