Effect of preparation procedure on phenols and color parameters of olive leaves drinks

Abstract

Cilj ovog rada bio je odrediti utjecaj pripreme i vremena stajanja na koncentraciju ukupnih fenola i boju napitka dobivenog od listića masline. U tu svrhu pripremljena je infuzija na tri različita načina, i to tako da je kontakt listića i vode početno zagrijane na 100oC bio 5, 10 te 15 min. Promjene su se pratile nakon stajanja od 5, 15, 30, 60, 240 te 420 min. Ukupni fenoli određeni su pomoću Folin-Ciocalteu reagensa, a boja primjenom kolorimetra. Prema rezultatima dobivenim provedenim istraživanjem, može se zaključiti da se unatoč oscilacijama pri različitim vremenima stajanja, količina ukupnih fenola povećava s vremenom kontakta, dok su promjene u boji vrlo neznatne. S vremenom stajanja infuzije sežu polagano prema tamnijim nijansama, a koncentracija ukupnih fenola se ne mijenja značajno.The aim of this study was to determine the influence of the soaking time and staying time on concentration of total phenols and colour of infusion obtained from olive leaves. For this purpose the infusion was prepared by pouring leaves with boiling water and leaving them in the water 5, 10 and 15 min and then by decanting. Changes were observed after 5, 15, 30, 240 and 420 min. Total phenols were determined by Folin-Ciocalteu reagent, and the Lab color parameters were measured by colorimeter. According to obtained results, it can be concluded that the amount of total phenols increased with the contact time of leaves and water, while the changes of color parameters were insignificant. During staying time no remarkable oscilations of total phenols were observed and by the measured color parameters it was evident that infusions slowly became darker shades