engleski

Physical, chemical and sensory properties of Dalmatian olive oils

Mediterranean diet is generally considered to be one of the healthier types of diets, and olive oil is its typical feature. The beneficial health effects of olive oil are due to high content of monousaturated fatty acids and antioxidant substances. Olive oil contains both lipophilic (tocopherol) and water soluble (polyphenols) antioxidants. Phenols from olive oil are responsible for its sensory properties (pungency and bitterness) which are important in traceability of its authenticity and origin as well in the procedure of protecting designation of origin (PDO) and protecting geographical indication (PGI). In this work we analyzed the 24 olive oils from two processing seasons. Physical and chemical properties of olive oils (content of fatty acids, triglycerides, sterols, waxes and tocopherols) were determined using GC and HPLC technique. For the first time, HPLC profile of polyphenolic extract for some Croatian olive cultivars was obtained. Dalmatian olive oil has relatively high content of oleic acid (18:1), and especially high content of essential fatty acids: linolic (18:2) and linoleic (18:3). The most abundant triglyceride was triolein. Relative share of β-sitosterol in total sterol content was higher than 80%, while relative share of total β-sitosterols was higher than 93%. Tocopherol content ranged from 122-375 mg/kg, while polyphenol content ranged from 106-645 mg of caffeic acid per kg of olive oil. The major differences between Dalmatian and other olive oils were detected by HPLC analyses of their polyphenolic extracts. HPLC results indicate that sensory profile of Dalmatian olive oils was influenced by lower content of tyrosol and hydroxytyrosol, compared to French and Spanish oils. This distinctiveness will be one of the important data in the writing specifications, an important document in the procedures for PDO or PGI protection.

olive oils; polyphenols; physical and chemical properties

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