Izolacija eteričnih olj limone in pomaranče in primerjava njihove sestave z eteričnim oljem iz leta 1985 s plinsko kromatografijo, sklopljeno z masno spektrometrijo

Faganel, Tina (author), Obreza, Aleš (mentor), Janeš, Damjan (comentor)

Citrus je najbolj razširjen rod agrumov iz družine rutičevk. Predstavniki imajo velik pomen v parfumski industriji, kjer predstavljajo vir številnih aromatičnih spojin s citrusnim vonjem. Citrusi so namenjeni zlasti proizvodnji soka, uporabljajo pa jih tudi v prehrambni in drugi industriji za izboljšanje okusa. Tradicionalno je pridobivanje citrusnih eteričnih olj s hladnim stiskanjem njihovih lupin. Glavna sestavina eteričnih olj limone in pomaranče je neoksidiran monoterpenski derivat, limonen. Ta deluje šibko protibakterijsko, protivirusno, antioksidativno in ima rahle insekticidne lastnosti. V eksperimentalnem delu naloge smo se najprej lotili destilacije eteričnega olja Citri aetheroleum iz leta 1985, ki je bilo shranjeno na Katedri za farmacevtsko kemijo. Posamezne frakcije smo ovrednotili s tankoplastno kromatografijo in na ta način določili ustrezno mobilno fazo za kolonsko kromatografijo. Organoleptično smo preverili razlike v vonju in barvi med posameznimi frakcijami. Sedem frakcij je imelo citrusni vonj, le osma je bila zelo viskozna tekočina neprijetnega vonja. Sestavine izbranih treh frakcij smo dodatno ločevali s kolonsko kromatografijo. Sledilo je pridobivanje izvlečkov iz svežih lupin limon in pomaranč po treh različnih postopkih: z ročnim stiskanjem, ekstrakcijo z etilacetatom in destilacijo z vodno paro. S plinsko kromatografijo, sklopljeno z masno spektrometrijo, smo nato analizirali sestavo vseh frakcij, pridobljenih z destilacijo, kolonsko kromatografijo in sveže pridobljene izvlečke limon in pomaranč ter jo primerjali s sestavo Citri aetheroleum. Največji delež, nad 90 % limonena, so imele začetne frakcije eteričnega olja, ki smo jih izolirali z destilacijo. V kasnejših frakcijah, 6, 7 in 8, sta bila najpogostejša monoterpenoida karvon in limonen-1,2-diol, ki sta bolj polarna in manj hlapna. Sveže izolirana eterična olja so se po sestavi precej razlikovala od eteričnega olja iz leta 1985. Najbolj pogoste spojine pa so bile tudi v teh vzorcih limonen, karvon, citral in limonen-1,2-diol. Do razlik je lahko prišlo zaradi različnih metod izolacije eteričnega olja in reakcij, ki so potekale v več kot treh desetletjih med shranjevanjem.

• Language: Slovenian
• Keywords: eterično olje, limonen, pridobivanje citrusnih eteričnih olj, sestava citrusnih eteričnih olj
• Work type: Bachelor thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2019
• PID: 20.500.12556/RUL-112897
• Publication date in RUL: 20.11.2019

Secondary language

• Language: English
• Title: Isolation of lemon and orange essential oils and comparison of their composition with the essential oil from 1985 by gas chromatography coupled with mass spectrometry

Abstract

Citrus is the most extended genus of citrus fruits in the Rutaceae family. Representatives have a huge impact in perfume industry, where they represent a source to numerous aroma compounds with citrus notes. Citruses are especially used in the production of juice, but they also have a big role in food and other industries to improve the taste. For many centuries the main method to produce citrus essential oils was cold pressing and it is still used to this day. The main compound of lemon and orange essential oils is unoxidized monoterpene derivate, limonene. Limonene works mildly antibacterial, antivirus, antioxidant and it has mild insecticide properties. We started our experimental part with distillation of essential oil, named Citri aetheroleum from 1985, which was kept at the Department of pharmaceutical chemistry, Faculty of Pharmacy. We assessed fractions with thin-layer chromatography and determined the mobile phase, suitable for column chromatography. We also checked and described differences in the smell and colour of individual fractions. Seven of eight fractions had citrus smell, the last one was viscous liquid with unpleasant odour. The ingredients of three chosen fractions were further separated with column chromatography. Next, we prepared extracts from fresh peels of lemons and oranges with three different procedures: by hand pressing, extraction with ethyl acetate and water vapour distillation. By gas chromatography coupled with mass spectrometry we analysed the composition of all fractions produced with distillation and column chromatography, and freshly prepared extracts of lemon and orange. We compared them with the composition of Citri aetheroleum. The highest percentage, above 90% of limonene, had the most volatile fractions obtained by distillation. In later fractions 6, 7 and 8 the most frequent compounds were monoterpenoids carvone and limonene-1,2-diol, more polar and less volatile compounds. Freshly prepared extracts differed significantly from the essential oil from 1985. The most common compounds in this samples were also limonene, carvone, citral and limonene-1,2-diol. Differences probably resulted from different methods of isolation and the reactions that took place during more than three decades of storage.

• Keywords: essential oil, limonene, extractions methods for citrus essential oils, composition of citrus essential oils