Policosanol variation in olive oil as a result of variety, ripening, and storage

Abstract

Despite their importance as bioactive compounds and authentication parameters in olive oil, the response of policosanol aliphatic alcohols to even the most influential sources of variability is practically unknown. To investigate policosanol variation in olive oil as a result of variety, ripening, and oil storage temperature, 36 samples were subjected to gas chromatographic (GC‐FID) and mass spectrometric (GC‐MS) analysis, and results were processed by univariate (ANOVA) and multivariate (SLDA) statistics. The concentration (mg/100 g) and relative amount (%) of pentacosanol accounted for the most variation due to variety. The largest influence of ripening was observed for pentacosanol (%) and docosanol (%). Docosanol, tricosanol, and tetracosanol amounts mostly increased during ripening, whereas those of pentacosanol, hexacosanol, heptacosanol, and octacosanol decreased in Črna and Rosinjola oils, whereas Buža showed different patterns in some cases. Variations as a result of storage were lower and inconsistent. Results suggest that the investigated olive oils retained the bulk of their health beneficial features of policosanol origin throughout shelf‐life. Relatively successful differentiation of oils achieved by multivariate models pointed to the potential use of policosanol alcohols as chemical indicators of varietal origin which are independent on ripening degree, and vice versa, applicable both for fresh and stored oils.Practical applicationsThe results obtained may serve producers to assess and optimize the suitability of individual steps in production, and develop strategies aimed at producing olive oils with targeted policosanol composition. More generally, the indicators of variety and ripening degree among policosanol aliphatic alcohols proposed may contribute to the scientific work on the authenticity and quality of olive oil which is an ever‐growing area, and be used for characterization, differentiation, authentication, and certification of olive oils of specific origin and attributes. The approach tested in this work could be utilized for developing more robust olive oil chemical composition specifications for European Union's Protected Designations of Origin (PDO) and other designations, because it considers the inter‐relationship between three factors of variability and extracts only the most useful and stable indicators or markers.Policosanol alcohol variation as a result of variety, ripening degree, and storage temperature was investigated. The use of policosanol variation as a chemical indicator and discriminator according to these factors was tested.