Variations in Physicochemical Quality Indices of Avocado Pulp Oils from Selected Varieties Grown across Different Sites and Seasons in the Lake Victoria Crescent Agro-Ecological Zone of Uganda

Abstract

This study evaluated the physicochemical quality indices of avocado pulp oils from four varieties (Fuerte, Hass, Reed and Semil 34) grown across three lo- cations and two harvest seasons in Uganda’s Lake Victoria Crescent Agro- ecological Zone. Parameters assessed included peroxide value (PV), acid value (AV), iodine value (IV), saponification value (SV) and thiobarbituric acid re- active substances (TBARS). The results revealed significant variations (p < 0.05) across varieties, sites and seasons. PVs were highest in Fuerte from MU- ZARDI during Season 1 (3.27 ± 0.36 meq O2/kg), while Hass and Semil 34 oils showed greater oxidative stability across sites. AVs ranged from 0.30 ± 0.02 to 0.67 ± 0.02 mg KOH/g, with Reed exhibiting consistently higher values, sug- gesting greater hydrolytic degradation. TBARS values were generally low, with Hass in Season 2 showing the least (1.04 ± 0.11 mg MDA/kg). IVs peaked in Reed (88.81 ± 1.33 mg I2/g), indicating a higher degree of unsaturation, while SVs ranged from 163.21 to 212.66 mg KOH/g, with Reed and Semil 34 show- ing the highest values. All indices fell within Codex Alimentarius limits, for virgin avocado oil, indicating acceptable oil quality. These findings highlight the influence of genotype and environment on avocado oil quality and provide guidance for optimizing harvest timing, variety selection and oil processing in Uganda and similar agro-ecological regions.