Micro-aqueous extraction of skipjack tuna head oil: A green strategy for maximizing yield while minimizing lipid...

This study evaluated micro-aqueous extraction (MAE) as a green strategy for recovering oil from skipjack tuna heads, comparing it with enzyme-assisted aqueous extraction (EAE) and heat extraction (HE). MAE achieved a maximum extraction yield of 69.7% at an oil volume fraction of 25%, significantly surpassing EAE (53.2%) and HE (39.1%), respectively. MAE oil exhibited superior quality with lower acid value, peroxide value, and malondialdehyde content, while retaining the highest polyunsaturated fatty acid content (47.57%) rich in EPA and DHA. Comprehensive volatile analysis by GC-MS and GC-IMS revealed significantly lower abundances of oxidation-derived volatiles in MAE oil, particularly key fishy-odor compounds, which were substantially reduced or absent relative to EAE and HE oils. Multivariate statistical analysis further confirmed distinct clustering of MAE oil based on its lower oxidation marker levels. These findings demonstrate that MAE effectively maximizes yield from low-fat tuna by-products while preserving nutritional value and minimizing fishy odor formation.