A dual-phase continuous process for lipid extraction from Litopenaeus vannamei by-products: process performance, lipid quality, and flavor

A novel LPSSD-LCPE integrated equipment was developed for shrimp lipid extraction. • LPSSD-LCPE improves shrimp fat yield and enriches phospholipids, astaxanthin and omega‑3 PUFAs. • LPSSD-LCPE inhibits trimethylamine formation and retains shrimp oil native flavour via higher ester content. • LPSSD-LCPE mitigates lipid degradation and off-flavour defects of conventional drying-extraction methods. Traditional extraction of Litopenaeus vannamei lipids often suffers from oxidation and low yields due to high-temperature and oxygen exposure. This study proposes an innovative, low-temperature, synergistic anaerobic process that combines low-pressure superheated steam drying (LPSSD) with low-temperature continuous phase-change extraction (LCPE). Compared to conventional methods, the LPSSD-LCPE coupling process establishes a dual protective barrier, achieving a significantly higher lipid extraction yield of 95.54% ± 1.39% (an increase of 14.15%). This technology resulted in higher EPA and DHA proportions while successfully enriching bioactive odd-chain fatty acids and nervonic acid (0.38%–0.97%). Furthermore, gas chromatography–mass spectrometry (GC–MS) analyses demonstrated that this process effectively suppresses off-flavor compounds like trimethylamine and 1-octen-3-ol, with isovaleraldehyde identified as the key aroma contributor. By balancing “deterioration inhibition” and “intrinsic flavor retention, “ the LPSSD-LCPE process provides a green, efficient pathway for the high-value recovery of bioactive lipids and precise flavor regulation in aquatic by-products. However, the subsequent valorization of high-value components in the defatted shrimp meal remains to be explored.