Karakterizacija lanenoga ulja inozemnih sorata uljnoga lana uzgojenih na području Republike Hrvatske

doctoral thesis

• Title (english): Characterization of flaxseed oil from foreign cultivars of flaxseed cultivated in the Republic of Croatia
• Author: Marko Obranović
• Mentor: Dubravka Škevin (mentor)
• Committee member: Sandra Balbino (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2015-07-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology
• Universal decimal classification (UDC): 665 - Oils. Fats. Waxes. Adhesives. Gums. Resins

Abstract

Cilj ovog istraživanja bio je odrediti svojstva lanenih ulja iz četri inozemne sorte uljnoga lana uzgajane na području Republike Hrvatske te odrediti utjecaj klimatskih uvjeta između cvatnje i žetve lana te različitih načina proizvodnje ulja na njihovu kvalitetu i kemijski sastav. Ukupan broj sati sijanja sunca imao je značajnog utjecaja na količinu ulja u sjemenu pri čemu se izdvojila sorta Niagara. Klimatski uvjeti i sorta su značajno utjecali na sastav masnih kiselina, sterola, karotenoida, tokokromanola i fenolnih spojeva. Suho i hladnije vrijeme u periodu vegetacije lana pozitivno je utjecalo na porast esencijalne α-linolenske (ω-3) masne kiseline. Hladno prešana ulja iz sorte žutog lana Oliwin izdvojila su se prema najvećem udjelu ω-3. Najviše sterola i karotenoida detektirano je kod ulja iz sorte Altess proizvedenog nakon kondicioniranja sjemena i na njihov udio pozitivno je utjecala povišena temperatura i broj sati sijanja sunca. Glavni predstavnici tokokromanola u svima uljima bili su γ-tokoferol i plastokromanol-8. Najviše količine tokokromanola detektirane su kod ulja iz sorte Biltstar i dobivenih nakon kondicioniranja sjemena. Prisustvo γ-tokoferola najbolje je koreliralo s porastom antioksidacijske aktivnosti ulja. Količina fenolnih spojeva u uljima bila je vrlo niska i značajno je pozitivno korelirala samo s godinom žetve, tj. višom temperaturom nakon cvatnje lana. Udio lignana u ulju je zanemariv u odnosu na njihovu količinu u sjemenu. Kako bi se dobila točna informacija o oksidacijskim promjenama na lanenom ulju potrebno je, uz standardne metode, u mjerenja uključiti i oksidirane oblike ciklolinopeptida. Na temelju sveukupnih istraživanja moguće je izdvojiti sorte Biltstar i Niagara kao najpogodnije za proizvodnju ulja u našem podneblju.

Abstract (english)

The aim of this study was to determine the properties of flaxseed oils from four foreign flaxseed varieties grown on the Croatian territory and to determine the influence of climatic conditions between flowering and harvesting of flax, different ways of oil production on their quality and chemical composition. The total number of sunshine hours had a significant impact on the amount of oil in the seed where the variety Niagara was singled out with the highest quantities of oil. Climatic conditions and variety significantly impacted composition of fatty acids, sterols, carotenoids, tocochromanols and phenolic compounds. Dry and cooler weather in period after flowering of flax positively influenced the increase in essential α-linolenic (ω-3) fatty acid. Cold-pressed oil from the varieties of yellow flax Oliwin was singled out by the largest share of ω-3. The most sterols and carotenoids were detected in oil produced from variety Altess after conditioning the seeds and their share is positively influenced by elevated temperature and hours of sunshine. The main representatives of tocochromanols in all oils were γ-tocopherol and plastochromanol-8. The highest quantities of tocochromanols were detected in oil from the variety Biltstar produced after conditioning of seeds. The presence of γ-tocopherol was best correlated with the increase in antioxidant activity of oil. The amount of phenolic compounds in the oils was very low and significantly positively correlated only with the year of harvest, i.e. higher temperature after flowering of flax. The share of lignans in the oil is negligible compared to their quantity in the seed. In order to obtain accurate information about the oxidative changes in flaxseed oil, along with standard methods, the analysis of oxidized cyclolinopeptides is needed. Based on the whole research data it possible to single out varieties Biltstar and Niagara as the most appropriate for oil production.

• Keywords: laneno ulje; sorta; klima; masne kiseline; tokokromanoli; steroli; fenoli
• Keywords (english): flaxseed oil; variety; climate; fatty acids; tocochromanols; sterols; phenols
• Language: croatian
• URN:NBN: urn:nbn:hr:159:205479
• Promotion: 2016-04-17
• Study programme: Title: Food Technology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti (doktor/doktorica znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-05-17 13:56:39