Oxidative Stability of Virgin Avocado Oil Enriched with Avocado Leaves and Olive-Fruit-Processing By-Products (Leaves, Pomace) via Ultrasound-Assisted Maceration

Virgin avocado oil (VAO), treasured for its nutritional and sensory properties, is susceptible to oxidation. To improve its oxidative stability, the feasibility of enrichment with antioxidants from avocado or olive-processing by-products via ultrasound-assisted maceration was explored. Dried, milled avocado (AL), olive leaves (OL), or olive pomace (OP) were ultrasound-macerated with laboratory-extracted VAO at 5, 10, and 20% levels. Induction-period (IP) values, determined via Rancimat (110 °C, 20 L/h), increased by 1.1-1.6-fold. Maceration with AL and OL added pigments (β-carotene, lutein, α-chlorophyll, and α-pheophytin) but only AL significantly boosted α-tocopherol levels (up to 3.7-fold). Extraction of major polar phenols (chlorogenic acid, oleuropein, and hydroxytyrosol) was poor (