The Impact of Drying Conditions on the Quality of Avocado Seed Oils

Abstract

Avocado seeds are an underutilised agro-industrial by-product with potential as a source of vegetable oil. This study evaluated the effects of shade drying and sun drying on the extraction yield and physicochemical quality of avocado seed oil. Ripe avocado seeds were divided into two 250 g batches. Shade drying was conducted at approximately 20 °C for 30 days, whereas sun drying required 7 days. The dried seeds were milled, and 10 g portions were macerated in 50 mL of hexane for 4 h before determination of the oil yield and acid, saponification, peroxide, and iodine values. Shade-dried seeds produced a slightly higher mean oil yield than sun-dried seeds (0.7125% versus 0.625%). The shade-dried oil also showed higher saponification (376.79 ± 53.05 mg KOH/g), acid (56.1 ± 5.2 mg KOH/g), and iodine values (55.98 ± 22.86 g I₂/100 g) than the sun-dried oil, which recorded corresponding values of 264.63 ± 108.17 mg KOH/g, 39.5 ± 5.1 mg KOH/g, and 43.01 ± 26.17 g I₂/100 g. Conversely, the peroxide value was slightly higher for the sun-dried oil (120.63 ± 39.05 meq O₂/kg) than for the shade-dried oil (115 ± 3 meq O₂/kg). These findings indicate that shade drying may better preserve unsaturation but may permit greater hydrolytic deterioration, whereas sun drying may increase oxidative exposure. Both oils showed substantial quality deterioration, demonstrating that drying and post-extraction handling require further optimisation.