Oil extraction and methyl esterification of fatty acids obtained from skipjack tuna by-products: antimicrobial property and preservative capability on pork sausage

This study assessed the effectiveness of fatty acid methyl esters (FAME) derived from skipjack tuna ( Katsuwonus pelamis ) head and viscera oil as a potential antimicrobial agent. The oil was extracted using lipase esterification and Soxhlet extraction methods. The functional pork sausage was then prepared with sodium alginate embedded with fish oil (FO) and FAME. The highest levels of eicosapentaenoic acid (4.15%) and docosahexaenoic acid (21.96%) were found in the head oil extracted using ethanol. Scanning electron microscope (SEM) images and results from the disc diffusion method provided evidence of FAME’s effect on Bacillus cereus cell damage and growth inhibition. From the sixth day of storage, bacterial growth in enriched samples was suppressed compared to control and sodium alginate (SA)-coated samples. In contrast to the FO-fortified sausage, the FAME-fortified sausage showed a significantly higher reduction in colony counts and overall acceptance in the sensory evaluation (6.97 ± 0.06). This indicates the enhanced antimicrobial properties of FAME and its potential use in functional foods.