Combined effects of cultivar, extraction technology, and geographic origin on physicochemical traits of Moroccan olive oil as revealed by multivariate analysis

Abstract

This study aimed at evaluating physicochemical traits of olive oil (‘Haouzia’ and ‘Moroccan Picholine’) according to extraction technologies (ETs: super-pressure SP, 2-phase 2 P, and 3-phase 3 P) across eight climatically contrasted Moroccan agroclimatic areas (AA). Our samples were classified as extra virgin olive oil (EVOO), whose traits varied (p < 0.05) among ETs, cultivars, and AA. EVOO from SP had high records of basic indices, most phytosterols, and trans fatty acids (TFA) due to partial oxidation during extraction, while continuous ETs (2 P and 3 P) displayed a better oil quality as demonstrated by routinely measured parameters. ‘Haouzia’ had the greatest saturated (SFA), monounsaturated (MUFA), polyunsaturated fatty acids (PUFA), and TFA. However, it had a lesser stability revealed by a low MUFA/PUFA and oleic/linoleic (O/L) as compared to ‘Moroccan Picholine’. Arid climatic areas had the highest palmitoleic, oleic acid, MUFA, MUFA/PUFA, and O/L and therefore the best oil stability as compared to the remaining agroclimatic areas. These variations were confirmed by principal component analysis, cluster analysis, and artificial neural networks. Important simple and multiple regression models with strong correlations were highlighted among the studied variables. In conclusion, environmental conditions have a key role to be considered when assessing olive oil quality and authenticity.