Eureka! Institutional Repository

Phenolic compounds are defined as the organic compounds with at least one aromatic benzene ring with one or more hydroxyls. These compounds are divided into simple phenols, phenolic acids, flavonoids or phenolic alcohols. Phenolic compounds are generally water-soluble, slightly fat-soluble and exhibit strong antioxidant activity. Due to their antioxidant activity, these compounds contribute in preclusion or deceleration of oil oxidation. In the present research, we examine the phenolic concentration, in olive paste of five different types of table olives (ripe green olives, green olives, backed black olives, Kalamata olives with stone and depitted) the olives were analyzed as purchased from the local market. In the samples the total phenolic compounds were determined using the Folin- Ciocalteau method after lyophilization and solvent extraction. In addition, the degree of oxidation of the oil contained in the olive paste, was determined. In order to prevent oil oxidation during sample preparation extraction was performed using supercritical carbon dioxide at low temperature immediate after lyophilization. Afterwards, the number of peroxides and the specific coefficients K 232 , K 268 , and ΔK were determined. The final conclusions concerning the levels of phenolic compounds in Greek table olives ranged between 72 and 129ppm. Upon the oxidation, the number of peroxides ranged from 22 to 32 meq O2 / kg of oil, the K 232 index from 1.341 to 2.380 and the K 268 index from 0.240 to 0.584.