Flavor evolution of Antarctic Krill (Euphausia superba) during thermal processing: insights from GC-IMS, GC-O-MS, and RATA.

Despite its high nutritional value, the application of Antarctic krill (Euphausia superba, AK) is hindered by complex off-odors. This study integrated electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction-gas chromatography-olfactometry-mass spectrometry (HS-SPME-GC-O-MS) with Rate-All-That-Apply (RATA) to map AK flavor evolution under various thermal treatments, including steaming (100 °C for 5 min), frying (220 °C for 5 min), and baking (180 °C for 1 min). Based on the screening criteria of relative odor activity values (ROAV >1), and GC-O detection frequency ≥ 3, 29 key aroma-active compounds were identified. While raw and steamed AK exhibited mild, lipid-derived profiles, frying exacerbated fishy odors due to a surge in lipid oxidation markers (e.g., hexanal, 1-octen-3-ol, and 1-penten-3-one). Conversely, baking optimized the balance of Maillard-lipid interaction profiles, generating sufficient pyrazine-mediated nutty and roasty notes while avoiding excessive lipid oxidation. Partial least squares regression (PLSR) modeling confirmed that baking achieved the highest consumer acceptability, correlated with fruity, meaty, and caramel attributes associated with markers such as trans-2-cis-6-nonadienal, 2-propylfuran, and 5-ethyl-2,3-dimethylpyrazine. These findings provide molecular-level insights for developing sensory-optimized krill products, facilitating the high-value utilization of AK resources.