Sinteza in olfaktorno vrednotenje derivatov vanilina

Horvat, Nuša (author), Obreza, Aleš (mentor)

Vanilin je organska spojina z molekulsko formulo C8H8O3. Je glavna sestavina hlapnih spojin vaniljevega stroka. Velik pomen ima predvsem v prehrambni industriji kot ojačevalec arome in okusa. Uporabljajo ga tudi v parfumski in kozmetični industriji kot dišavo in v farmaciji kot sredstvo za prekrivanje neprijetnega vonja. Naravni vanilin oz. vaniljev izvleček pridobivajo iz strokov vrst Vanilla planifolia in Vanilla tahitensis, ki jih najprej posušijo, nato ekstrahirajo z organskim topilom. Končni produkt poleg vanilina vsebuje še približno dvesto drugih spojin, ki so v vaniljevem stroku v zelo majhnih koncentracijah. Sintezni vanilin pridobivajo s kemijskimi pretvorbami iz gvajakola, lignina in koniferina. Vse večje pa je zanimanje za biotehnološko pridobivanje vanilina. Namen diplomske naloge je bil sintetizirati derivate vanilina in jih ovrednotiti z vonjalnim testom, da bi ugotovili, kako sprememba v kemijski strukturi spojine vpliva na njihov vonj. Sintetizirali smo deset derivatov vanilina: etre, estre in reducirani derivat. Derivate smo očistili s kolonsko adsorpcijsko kromatografijo, kjer smo kot mobilno fazo uporabili mešanico etilacetata in heksana v razmerju 1 : 2. Identiteto sintetiziranih produktov smo potrdili z analiznimi metodami. Končne spojine smo olfaktorno ovrednotili z vonjalnim testom, kjer so nas zanimale prijetnost in jakost vonja ter asociacije na druge vonje. Rezultati vonjalne analize so pokazali, da spremembe v kemijski strukturi pomembno vplivajo na spremembo vonja. Trije derivati so ohranili prijeten vonj po vanilinu, ostali so bili neprijetni. Na intenzivnost vonja vpliva predvsem molekulska masa spojine in funkcionalne skupine oz. polarnost molekule. Večji kot sta molekulska masa in polarnost spojine, manjša je hlapnost in s tem intenzivnost vonja. Vonjalna analiza je pokazala, da imajo sintetizirani estri večjo jakost vonja kot etri. Z rezultati vonjalne analize smo ugotovili, da kemijska zgradba, predvsem funkcionalne skupine in velikost molekule, pomembno vplivajo na prijetnost in jakost vonja.

• Language: Slovenian
• Keywords: vanilin, vanilja, izvleček vanilje, vonjalna analiza
• Work type: Bachelor thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2020
• PID: 20.500.12556/RUL-117104
• Publication date in RUL: 24.06.2020

Secondary language

• Language: English
• Title: Synthesis and olfactory evaluation of vanillin derivatives

Abstract

Vanillin is an organic compound with the molecular formula C8H8O3. It is the main ingredient of the volatile compounds of the vanilla pod. Mostly, it has great significance as aroma and flavor enhancer in food industry. It is also used in the perfume industry and cosmetic industry as a fragrance and the pharmacy as an agent for covering an unpleasant odor. The natural vanillin or vanilla extract is produced from the pods of Vanilla planifolia and Vanilla tahitensis, which are first dried and then extracted by organic solvent. In addition to vanillin, the end product contains also approximately two hundred other compounds that are present in the vanilla pod in very small concentrations. Synthetic vanillin is prepared by chemical transformations from guaiacol, lignin, and coniferin. The interest in the biotechnological extraction of vanillin is increasing. The purpose of the bachelor’s thesis was to synthesize derivatives of vanillin and evaluate them by an olfactory test to ascertain how the change in the chemical structure of a compound influences their scent. We synthesized ten derivatives of vanillin: ethers, esters, and the reduced derivative. We cleansed the derivatives by the column adsorption chromatography where we used the mixture of ethyl acetate and hexane in the ratio 1 : 2. We confirmed the identity of synthesized products with analytical methods. We evaluated the end compounds olfactory by an olfactory test where we were interested in pleasantness and the scent intensity, as well as in the associations of the other scents. The results of the olfactory analysis showed that the changes in the chemical structure influence the change in the scent importantly. Three derivatives preserved the pleasant scent of vanillin. The others were unpleasant. The molecular mass of the compound and the functional group and the polarity of the molecule influence the intensity of the scent mostly. Greater the molecular mass and the polarity of the compound are, lesser is the vaporization and thus the scent intensity. The olfactory analysis showed that synthesized esters have greater scent intensity than ethers. By the results of the olfactory analysis, we ascertained that the chemical structure (mostly of the functional group and the size of the molecule) influences the pleasantness and the scent intensity importantly.

• Keywords: vanillin, vanilla, vanilla extract, olfactory analysis