https://doi.org/10.17113/ftb.57.02.19.5921 


Polyphenol-Based Design of Functional Olive Leaf Infusions^§ 


Željka Peršurić^#, Lara Saftić^#, Dora Klisović and Sandra Kraljević Pavelić* 


University of Rijeka, Department of Biotechnology, Centre for High-Throughput Technologies, Radmile Matejčić 2, 51000 Rijeka, Croatia  



Article history:
Received: 30 June 2018
Accepted: 22 May 2019
 



Key words: 
olive leaf infusion, LC-QQQ, polyphenols, functional infusions 



Summary: 
The beneficial properties of polyphenols are widely recognized, and polyphenol-rich olive oil, which is part of the typical Mediterranean diet, has been identified as having positive health effects. However, over the past decade, olive leaves have been discovered as an alternative polyphenol-rich source. This is particularly interesting in the context of the growing interest in functional foods, as well as in terms of the management of biological waste, including olive leaves that are left over from the production of olive oil. Previous studies on olive leaves  confirmed that they have a high phenolic content, which explains their previously described strong antibacterial, antimicrobial and antiviral activity. Therefore, the major aim of our work is to comprehensively determine olive leaf phenolic content in cultivars Istarska bjelica, Leccino and Buža as a natural source of bioactive compounds suitable for daily consumption in the form of infusion. For this purpose, we examined the influence of olive leaf cultivar, maceration time and temperature on the phenolic composition of final infusions. Phenolic compounds were analysed by liquid chromatography (LC) coupled to a triple quadrupole mass spectrometer (LC-QQQ). As expected, the results indicate the significant influence of not only the olive cultivar but also of maceration parameters on the qualitative and quantitative phenolic composition. The highest phenolic compound content was obtained in the infusion of Istarska bjelica leaves after 15 min of maceration. However, the Buža olive leaf infusion had the most diverse phenolic composition. Furthermore, we designed several functional olive leaf infusion mixtures with phenolic compositions adjusted based on the desired health effect. The results show the role of phenolic composition adjustment in the development and improvement of the quality of functional olive leaf infusions.   




*Corresponding author:    +38551584550
                                              sandrakp@biotech.uniri.hr   



^#These authors contributed equally 



^§Paper was presented at the 9th International Congress of Food Technologists, Biotechnologists and Nutritionists, 3-5 October 2018, Zagreb, Croatia