Profil hlapivih spojeva i senzorska svojstva nerafiniranog bučinog ulja proizvedenog uz prženje

master's thesis

• Title (english): Volatile compounds profiles and organoleptic properties of unrefined roasted pumpkin seed oil
• Author: Petra Regović
• Mentor: Sandra Balbino (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Section for Food Plant Design); Zagreb
• Defense date and country: 2013-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu provedena su ispitivanja na 25 uzoraka nerafiniranog bučinog ulja. Kao osnovni pokazatelji kvalitete ulja, određeni su peroksidni broj i udjel slobodnih masnih kiselina, koji su bili daleko ispod granica utvrđenih Pravilnikom (NN 41/12). Sastav masnih kiselina pokazao je da je dominantna masna kiselina u svim uzorcima linolna, a slijede palmitinska, stearinska i oleinska. Na osnovu senzorske procjene vidljiva je dobra senzorska kvaliteta većine uzoraka bučinog ulja. Hlapivi sastojci analizirani su pomoću GC-MS-a uz mikroekstrakciju na čvrstoj fazi (SPME) te je utvrđeno da se aroma nerafiniranog bučinog ulja sastoji od aldehida, ketona, alkohola, kiselina, pirazina, estera, derivata alkana i alkena, sumpornih i ostalih spojeva. Najveću korelaciju sa specifičnom aromom bučinog ulja imaju aldehidi (2-metil-butanal i 3-metil butanal) i pirazini (2,5-dimetil-pirazin + 2,4dimetil-pirazin) koji nastaju tijekom procesa prženja. Na osnovu dobivenih rezultata provedena je analiza osnovnih komponenti (PCA), kojom su u prostoru dva faktora vidljive razlike između uzoraka s najboljim i najlošijim ocjenama.

Abstract (english)

In this study, tests were made on 25 samples of unrefined roasted pumpkin seed oil. As main quality indicators, peroxide value and free fatty acid content were examined. Both parameters were far below the limits established by the Croatian Regulations (NN 41/12). Fatty acid composition consisted of palmitic, stearic, oleic and most common, linoleic acid. Sensory evaluation showed good sensory quality of most samples. Volatile compounds were extracted by solid-phase microextraction and analysed by GS-MS. It was determined that aroma of unrefined pumpkin seed oil is composed of aldehydes, ketones, alcohols, acids, pyrazines, esters, derivatives of alkanes and alkenes, sulfur compounds and other compounds. The largest influence on the specific aroma of pumpkin seed oil have aldehydes (2-methyl-butanal and 3-methyl butanal) and pyrazines (2,5-dimethyl-pyrazine + 2,4dimethyl-pyrazine) that form during the roasting process. Based on the results, principal component analysis was made, and it showed noticeable differences between the samples with the best and worst grades in the space of two factors.

• Keywords: bučino ulje; GC-MS; sastav masnih kiselina; senzorska analiza; SPME
• Keywords (english): fatty acid composition; GC-MS; pumpkin seed oil; sensory analysis; SPME
• Language: croatian
• URN:NBN: urn:nbn:hr:159:418308
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-05 11:28:25