Revalorization of Lupinus mutabilis seed oil via clean expeller extraction and comprehensive chemical characterization

Abstract

This study aims to revalorize Lupinus mutabilis (L. mutabilis) seed oil through expeller extraction method and its extensive characterization. Oil recovery accounted for 44 % based on the total fat content of L. mutabilis seeds (25 %). The oil showed an initial peroxide value of 4.1 meq O2/kg, p-anisidine value of 1.0, and TOTOX value of 9.2, all within acceptable limits for vegetable edible oils. The fatty acid (FA) composition was predominantly unsaturated, with oleic acid (cis-9 C18:1, 44 g/100 g) and linoleic acid (cis-9, cis-12 C18:2, 34 g/100 g) as major FAs. For the first time, the positional distribution of FAs in the triacylglycerol backbone was determined, showing a balanced presence of oleic and linoleic acids in the sn-2 and sn-1,3 positions. Additionally, this study reports for the first time the quantification (11 g/100 g) and characterization of the phospholipid (PL) fraction. The main PL was phosphatidylcholine, followed by phosphatidylethanolamine and lysophosphatidylcholine. The total phenolic content was 99 mg gallic acid equivalents (GAE)/kg oil. The oil also contained 7120 mg/kg of sterols and 494 mg/kg of α-tocopherol. These results demonstrate the potential of expeller-extracted L. mutabilis seed oil for nutraceutical applications, as a natural source of health-promoting lipids and bioactive compounds