Influence of cultivar and press-extraction temperature on antioxidants, quality and stability of avocado (Persea americana Mill.) oil

Avocado fruits unsuitable for consumption are often used to produce oil, prized by food and cosmetic industries. This research assessed how press-extraction temperatures (20 °C and 80 °C) and cultivars affected avocado oil color, antioxidants, fatty acids composition, physico-chemical parameters, saponification value, nutritional and health-related indices and stability. Fruits and oils from cultivars Fuerte, Gween, Hass, Topa Topa, and Zutano were evaluated, and significant differences (p ≤ 0.05) among varieties as well as between extraction temperatures were detected for most traits. Fresh avocado pulp contained 13.6–15.7 g/100 g lipids; the extraction yield was 36.5% at 20 °C and 49.8% at 80 °C. In general, 20 °C better preserved chlorophyll (61.5 mg/kg) than 80 °C (43.8 mg/kg). The carotenoid β-cryptoxanthin was lower in the samples extracted at 80 °C. Gween oil had the highest tocopherol content (on average, 229.8 mg/kg); β-tocopherol (susceptible to extraction temperature) was the most abundant (49.10%), followed by α-tocopherol (38.15%) and γ-tocopherol (12.75%). The oils extracted at 80 °C showed higher density, viscosity and acidity but inferior refractive index, peroxide and iodine than those extracted at 20 °C. The oxidative stability index at 110 °C, measured by Rancimat, decreased in oils extracted at 80 °C compared to those extracted at 20 °C (9.1 vs. 10.4 h). Pressure-extracted avocado oil maintained excellent qualitative and technological properties at both extraction temperatures, thus suggesting its suitability for several food uses, including salad dressing and, thanks to its thermal stability, cooking.