Fractional hydrodistillation and rectification of Juniper berry (Juniperus communis L.) essential oil

U ovoj doktorskoj disertaciji ispitivani su kinetika hidrodestilacije, prinos, sastav i frakcionisanje etarskog ulja ploda kleke (Juniperus communis L.) ubranog na Kopaoniku. OdreĎeni su prinos, sastav etarskog ulja i razvijena su tri fenomenolońka modela kinetike hidrodestilacije etarskog ulja iz ploda kleke. Modeli su zasnovani na pretpostavci da se etarsko ulje koje se nalazi na povrńini čestica biljke izdvaja brzom destilacijom i ta faza je nazvana "ispiranje". Preostalo etarsko ulje se izdvaja kroz dve faze, tj. dve difuzije. Tokom prvog difuzionog procesa, nazvanog "neometana difuzija", dolazi do prenosa etarskog ulja kroz rupture organa bez ometanja ka povrńini čestica biljnog materijala. Sa druge strane, tokom drugog difuzionog procesa, nazvanog "ometana difuzija", dolazi do prenosa etarskog ulja kroz membrane neońtećenih organa i druge barijere prisutne u česticama biljnog materijala. Razvijeni modeli pokazuju vrlo dobro slaganje sa eksperimentalnim podacima, pri čemu su verifikovani i za slučajeve dobijanja etarskog ulja tehnikom hidrodestilacije iz drugih biljnih vrsta. S obzirom da je jedan od razvijenih modela, koji polazi od pretpostavke da maksimalne brzine izdvajanja u fazama ispiranja i difuzije nisu na početku procesa destilacije, već nakon odreĎenog vremenskog intervala, zasnovan na fizičkom mehanizmu ekstrakcije etarskog ulja kleke, ima najveće vrednosti koeficijenta determinacije i nisko srednje relativno procentualno odstupanje, preporučen je za modelovanje kinetike izdvajanja etarskog ulja kleke pomoću klasične hidrodestilacije i posebno mikrotalasne hidrodestilacije...The kinetics of hydrodistillation (HD), as well as the yield, the composition and the fractionation of essential oil from juniper (Juniperus communis L.) berries collected at the Kopaonik montain was studied. The yield and the composition of the essential oil were determined. Three models of the essential oil HD kinetics were developed, based on the assumption that juniper essential oil (JEO) from the external surfaces was extracted during the fast initial stage of distillation process, the so-called "washing". The remaining JEO was extracted during the two stages, i.e. two diffusions. During the first diffusion process, called "unhindered diffusion", the essential oil from the ruptured reservoirs diffused without any limitations towards the external surface of the plant particles. On the other side, during the second diffusion process, called "hindered diffusion", the essential oil transfered from the intact reservoirs through the membranes and other barriers presented in the plant particles. Developed models were shown to fit very well with the experimental data. Furthermore, they were also verified for the extraction of the essential oils by HD from other plants. Since one of developed models based on assumption that maximum washing and diffusion rates' values were not at the beginning of the distillation process, but occured later, was based on the physical mechanism of JEO extraction and had the largest coefficient of determination, the low MRPD value and the statistically significant parameters, it was recommended for the modeling the kinetics of JEO extraction by HD and especially microwave-assisted HD (MAHD)..