Analysis of volatile compounds from samples of nonflavored and flavored olive oils : diploma thesis

Zbog svoje specifične arome i nutricionističkih benefita maslina (Olea europea L.) jedna je od najpopularnijih biljaka Dalmacije. Kako bi se poboljšala osjetilna i nutricionistička svojstva, već poznatom mirisu i okusu maslinova ulja, dodaju se nove arome. U aromatizaciji ulja najčešće se koriste ružmarin, timijan, origano i slične aromatične biljke te plodovi citrusa. U svrhu izolacije hlapljivih spojeva tri nearomatizirana maslinova ulja i tri maslinova ulja aromatizirana gorkom narančom, origanom i ružmarinom, podvrgnuta su hidrodestilaciji te mikroekstrakciji vršnih para na čvrstoj fazi (HS-SPME). Svi uzorci hlapljivih spojeva, destilati i vršne pare, analizirani su veznim sustavom plinska kromatografija-spektrometrija masa (GC-MS). Glavni spojevi u destilatu maslinovog ulja, uzorak 1, su nezasićena masna kiselina, oleinska kiselina, aldehid nonanal te (E)- i (Z)- izomeri nezasićenog alifatskog aldehida deka-2,4-dienala. U destilatu uzorka 2 ističe se nezasićeni C 6 aldehid (E)-heks-2-enal i oleinska kiselina. Glavni spojevi destilata uzorka 3 su oleinska kiselina i etil-oleat. C 6 aldehid (E)-heks-2-enal nije identificiran u uzorcima 1 i 3, dok je C 6 alkohol heksan-1-ol identificiran u sva tri destilata, ali s malim udjelima. Navedeni spojevi su nositelji arome koja se opisuje kao „zelena“. Glavni sastojci vršnih para uzorka 1 i 2 su C 6 spojevi (E)-heks-2-enal, heksanal te heksan-1-ol. Uzorak 2 sadrži još i oleinsku kiselina. Vršne pare uzorka 3 se dosta razlikuju. Tu prevlada ester butanske kiseline, etil-butanoat i etanol. C 6 aldehidi (E)-heks-2-enal i heksanal u uzorku 3 nisu identificirani, već C 6 alkohol heks-3-en-1- ol. U destilatu maslinovog ulja aromatiziranog gorkom narančom ističe se monoterpenski ugljikovodik limonen. Glavni spojevi destilata maslinovog ulja aromatiziranog origanom su također monoterpeni. Najveći udio zauzima fenol timol te ugljikovodici p-cimen i limonen. Destilat maslinovog ulja aromatiziranog ružmarinom sadrži monoterpene timol, limonen, 1,8-cineol, p-cimen, kamfor te α-pinen. Glavni sastojci vršnih para maslinovog ulja aromatiziranog gorkom narančom su limonen i triterpenski ugljikovodik skvalen. Najistaknutiji spojevi vršnih para maslinovog ulja aromatiziranog origanom su monoterpeni limonen, p-cimen i timol. Kao i u prethodnom i u ovom uzorku identificiran je triterpenski ugljikovodik skvalen. Uzorak vršnih para maslinovog ulja aromatiziranog ružmarinom karakterizira visoki udio skvalena te oleinska kiselina. Due to it's specific aroma and valuable nutritional benefits, olive tree (Olea europea L.) is one of the most popular plants in Dalmatia. In order to improve the sensory and nutritional properties, various aromas are added to the olive oils. Rosemary, thyme, oregano and various Citrus fruits are most often used in the aromatization of oils. For the purpose of isolating volatile compounds, three non-flavored olive oils and three olive oils flavored with bitter orange, oregano and rosemary, were subjected to hydrodistillation and solid phase microextraction method (HS-SPME). All volatile compound samples were analyzed by gas chromatography-mass spectrometry (GC-MS). The main compounds in the olive oil distillate, sample 1, are unsaturated fatty acid, oleic acid, aldehyde nonanal and (E)- and (Z)-isomers of deca-2,4-dienal. In the sample 2 distillate, unsaturated C 6 aldehyde (E)-hex-2-enal and oleic acid stand out. The main compounds of sample 3 distillate are oleic acid and ethyl oleate. C 6 aldehyde (E)-hex-2- enal, was not identified in samples 1 and 3, while C 6 alcohol hexan-1-ol was identified in all three distillates, but with small proportions. These compounds are carriers of so-called "green" aromas. The main constituents of headspace vapours of samples 1 and 2 are C 6 compounds (E)-hex-2-enal, hexanal and hexan-1-ol. Sample 2 also contains oleic acid. The headspace vapors of sample 3 are different with ethyl butanoate and ethanol as main compounds. The C 6 aldehydes (E)-hex-2-enal and hexanal in sample 3 were not identified, but the C 6 alcohol hex-3-en-1-ol was. In the distillate of olive oil flavored with bitter orange the monoterpene limonene stands out. The most prominent compounds of oregano flavored olive oil distillate are also monoterpenes. The largest share takes phenol thymol, and hydrocarbons p- cymene and limonene. The rosemary flavored olive oil distillate contains monoterpenes thymol, limonene, 1,8-cineole, p-cymene, camphor and α-pinene. The main ingredient of the headspace vapors of bitter orange flavored olive oil is limonene, as well as the triterpene squalene. The most prominent compounds of the headspace vapors of oregano flavored olive oil are monoterpenes limonene, p-cymene and thymol. As in the previous sample, the triterpene squalene was identified too. The sample of headspace vapors of rosemary flavored olive oil is characterized by an extremely high content of squalene followed by oleic acid.