Phytochemical Factor Analysis of Some Extra Virgin Olive Oils (Olivae oleum) and the Effects of Storage Under Different Conditions—Simulating General Consumer Behavior

Abstract

Olive oil, one of the foods that has a wide place in production and consumption worldwide, is considered important in terms of taste and health, thanks to the components it contains. However, incorrect approaches to storing this seasonally produced food cause significant losses for many consumers. In this study, by simulating a general consumer behavior, three extra virgin olive oils (EVOO) produced annually were procured and stored under different conditions for 6 months; and the effects of time, temperature, and light parameters were examined. The phytochemical properties of olive oils were analyzed and repeated after 3 and 6 months. During the process, negative changes occurred in free fatty acid values from 0.51 ± 0.01 to 2.04 ± 0.01 (oleic acid%), total phenolic content amounts from 481.77 ± 3.24 to 96.02 ± 0.94 (mg GAE/kg oil), total antioxidant capacity from 215.93 ± 1.67 to 11.21 ± 0.17 (mg TE/kg oil), and peroxide values from 13.58 ± 0.34 to 31.96 ± 0.85 (meq O₂/kg). Oleic acid ratios were between 66.37 ± 1.09% (Halhalı) and 72.97 ± 1.19% (Memecik) in all processes and samples. No defect was detected in sensory test results for up to 6 months. Among the most important phenolic components, hydroxytyrosol (max 33.18 ± 0.81 mg/kg) and tyrosol (max 3.93 ± 0.03 mg/kg) showed a fluctuating change, and oleuropein (max 7.40 ± 0.12 mg/kg) tended to decrease. Statistical results performed with all samples and parameters using principal component analysis showed that oleic acid, linoleic acid, hydroxytyrosol, total unsaturated fatty acid values, some terpenes, and C6 volatile components were the most characteristic components for the oils studied. Additionally, the results showed that time was more effective than temperature and light variables in storage.