Integrated impact of environmentally friendly extraction and recovery methods on almond oil quality: Insights from a lipidomic perspective

Abstract

Although aqueous and enzymatic extractions are solvent-free alternatives for extracting oil and proteins from almond flour, most of the extracted oil becomes entrapped in an emulsion and needs demulsification for recovery. To assess how extraction and demulsification methods impact yields and quality, a lipidomic approach was used to investigate the effects of aqueous and enzymatic extractions processes and recovery strategies, including pH-shift and protease addition, on almond oil quality. Liquid chromatography-mass spectrometry, conventional oxidation markers (peroxide value, p-anisidine), fatty acid profile, lipid class, total phenolic content and antioxidant activity were employed to determine the combined impact of extraction and recovery methods on lipid quality and composition. Peroxide value (1.8–2.0 mEq/kg oil), p-anisidine (0.1–0.4), and fatty acid composition of the oils (18:1 72%–75%, 18:2 22%–25%, 16:0 4%–5%) showed no significant changes based on extraction and recovery methods. However, oxylipin analysis demonstrated that the solvent-extracted oil had higher levels of 13-hydroxyoctadecadienoic acid (13-HODE) and 12(13)-epoxyoctadecenoic acid (12(13)-EpOME) compared to aqueous and enzymatically extracted oils, regardless of the demulsification method. Additionally, the solvent-extracted oil exhibited lower phenolic content and antioxidant capacity. This work provides valuable insights into how environmentally friendly extraction and recovery methods impact almond oil quality, contributing to processing optimization.