Object: Five common monovarietals (Picual, Arbequina, Coratina, Frantoio and Koroneiki) olive oil produced in two primary suitable areas (Xichang, Sichuan Province and Longnan, Gansu Province) for Olea europaea L. in China were analyzed.
Methods Used: The quality parameters (free acidity (FA), peroxide value (PV), and spectroscopic indices (K232, K270, and ΔK)) assessed of olive oil samples were determined by International Organization for Standardization (ISO) methods ISO 660, ISO 3960 and ISO 3960, respectively. Fatty acids were determined as FAMEs obtained by trans-esterification using potassium hydroxide in methanol (IOC, 2015), and analyzed by GC. Tocopherol contents and the phenolic compounds were determined by HPLC. The analysis of squalene was performed by GC-MS.
Results: Quality parameters of all samples complied with the limit of extra virgin olive oil (COI T.15 NC. No.3-REV.7-2013). Cultivars and regions had no effects on the quality parameters of olive oils. Oleic acid (C18:1) was the major fatty acid in samples, and varieties were the main influencing factors. Tocopherol contents, phenolic compounds, and squalene were affected by both varieties and origins. α-tocopherol occupied higher than 90% of total tocopherol and secoiridoids were the primary phenolic compounds in the oil.
Conclusions: The results showed that both the cultivars and the geographical origins have influence on the chemical compounds of olive oils. Besides the contents of total polyphenol were seemingly lower, Chinese olive oils were as qualified as the same monovarietals oil from Mediterranean regions.