engleski

Phenolic acids and their derivatives in extra virgin olive oil from Croatia

Introduction. Extra virgin olive oil (EVOO) has nutritional and sensory characteristics that make it unique among vegetable oils and as such, it is a basic component of the Mediterranean diet. The importance of EVOO is attributed both to its high content of oleic acid and richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of several human diseases. Apart from the interest in composition of the polar fraction of EVOO, the determination of these compounds also helps to understand their health benefits including reduction of risk factors of coronary heart disease, prevention of several varieties of cancer and modification of immune and inflammatory responses. The polar phenolic compounds of EVOO belong to different classes: simple phenols, phenolic acids and their derivatives, flavonoids, lignans and secoiridoids. Some of phenolic acids such as caffeic, vanillic, syringic, p-coumaric, o- coumaric, protocatechuic, sinapic and p- hydroxybenzoic acids were the first group of polyphenols observed in EVOO. Materials and methods. Three samples of EVOO from Istra (Bjelica, Buža i Žižolera) and a sample from Ugljan island were analysed in this study. Extraction of phenols from EVOO was carried out using the ultrasound-assisted liquid-liquid extraction (US-LLE) method. The HPLC-DAD analysis was performed. Results. Results show that phenolic acids and their derivatives (p- hydroxybenzoic acid, homovanilyl acohol, vanillin, vanillic, syringic, p-coumarinic, benzoic and ferulic acids) are present in each analysed EVOO. Their concentration is below 1mg/kg olive oil, as it is usually reported for EVOO in literature. Conclusion. Analysed EVOO derived from Croatia (Istra and Ugljan island) are rich in important minor phenolic acids and their derivatives which provide good properties of oil in nutrition and disease prevention.

Olive oil ; phenols ; phenolic acid

nije evidentirano