Analiza eteričnih olj rožmarina (Rosmarinus officinalis L.) in lovorja (Laurus nobilis L.) na slovenskem tržišču

Simić, Pavle (author), Poklar Ulrih, Nataša (mentor), OGRINC, NIVES (comentor)

V okviru magistrske naloge smo določali antioksidativne lastnosti, kemijsko sestavo in pristnost eteričnih olj rožmarina (Rosmarinus officinalis L.) in lovorja (Laurus nobilis L.), dostopnih na slovenskem tržišču. Antioksidativno aktivnost eteričnih olj rožmarina in lovorja smo določili z metodo DPPH•. Z metodo Folin-Ciocalteu smo določali koncentracije skupnih fenolnih spojin ter ugotovili pozitivno korelacijo med vsebnostjo skupnih fenolnih spojin in antioksidativno aktivnostjo v eteričnih oljih rožmarina in lovorja. Pri določanju antilipoperoksidativnega delovanja (TBARS test) smo ugotovili, da eterična olja lovorja bistveno bolj učinkovito zavirajo lipidno peroksidacijo v primerjavi z eteričnimi olji rožmarina. S plinsko kromatografijo z masnim detektorjem (GC-MS) smo analizirali kemijsko sestavo eteričnih olj rožmarina in določili številne terpenoidne spojine, med katerimi sta 1,8-cineol in kafra prevladujoči, sledijo monoterpenski ogljikovodiki, kot sta α- in β-pinen ter oksigenirani monoterpeni vključno z borneolom in bornil acetatom. V eteričnih oljih lovorja smo določili spojino 1,8-cineol kot prevladujočo spojino ter nekatere druge spojine kot so α-terpinil-acetat, sabinen, linalol, α-pinen, β-pinen ter metil evgenol. Izotopsko sestavo ogljika (δ13C) hlapnih organskih spojin v eteričnih oljih rožmarina in lovorja smo določili s plinsko kromatografijo sklopljeno z masnim spektrometrom za analitiko stabilnih izotopov lahkih elementov preko sežigne enote (GC-C-IRMS). Analiza vzorca R8 razkriva visoko vsebnost limonena in razlike v δ13C vrednostih, kar kaže na dodatek sintetičnih spojin ali eteričnoh olj citrusov, bogatih z limonenom, medtem ko opazovanja pri 1,8-cineolu sugerirajo uporabo bolj dostopnega eteričnega olja sivke za zmanjšanje stroškov. Izotopska analiza prav tako kaže na neustrezno deklaracijo pri treh vzorcih, kar poudarja potrebo po nadaljnjih raziskavah. Vzorci eteričnega olja lovorja iz Turčije, Albanije in Hrvaške izkazujejo skladne vrednosti δ13C, kar kaže na geografsko usklajenost izotopskih vrednosti med vzorci iz posameznih regij.

• Language: Slovenian
• Keywords: rožmarin, Rosmarinus officinalis, lovor, Laurus nobilis, eterično olje, antioksidativna aktivnost, GC-MS, GC-IRMS, δ13C, potvorbe, pristnost
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [P. Simić]
• Year: 2024
• PID: 20.500.12556/RUL-158528
• UDC: 665.52/.54
• COBISS.SI-ID: 199099395
• Publication date in RUL: 15.06.2024

Secondary language

• Language: English
• Title: Analysis of rosemary (Rosmarinus officinalis L.) and bay leaf (Laurus nobilis L.) essential oils on the Slovenian market)

Abstract

In the framework of the master's thesis, the antioxidant properties, chemical composition and authenticity of essential oils of rosemary (Rosmarinus officinalis L.) and bay leaf (Laurus nobilis L.) available on the Slovenian market were determined. The antioxidant activity of rosemary and bay leaf essential oils was determined by the DPPH• method. The Folin-Ciocalteu method was used to determine the concentrations of total phenolic compounds and a positive correlation was found between the content of total phenolic compounds and the antioxidant activity of rosemary and laurel essential oils. Using the TBARS assay, we found that bay leaf essential oils were significantly more effective in inhibiting lipid peroxidation compared to rosemary essential oils. The chemical composition of rosemary essential oils was analysed by GC-MS and a number of terpenoid compounds were determined among which 1,8-cineole and camphor are the predominant ones followed by monoterpene hydrocarbons such as α- and β-pinene, and oxygenated monoterpenes, including borneol and bornyl acetate. The compound 1,8-cineole was identified as the predominant compound in the essential oils of bay laurel, as well as some other compounds such as α-terpinyl acetate, sabinene, linalool, α-pinene, β-pinene and methyl eugenol. The carbon isotopic composition (δ13C) of the volatile organic compounds of rosemary and bay leaf essential oils was determined by GC-C-IRMS. Analysis of sample R8 reveals high limonene content and differences in δ13C values, suggesting the addition of synthetic compounds or limonene-rich citrus essential oils, while the observations for 1,8-cineole suggest the use of the more readily available lavender essential oil to reduce costs. The isotopic analysis also suggests suspicions of adulteration in three samples, highlighting the need for further research. Bay leaf essential oil samples from Turkey, Albania and Croatia show consistent δ13C values, indicating geographical consistency in isotopic values between samples from each region.

• Keywords: rosemary, Rosmarinus officinalis, bay leaf, Laurus nobilis, essential oils, antioxidant activity, GC-MS, GC-IRMS, δ13C, adulteration, authenticity