magistrsko delo
Uroš Jedlovčnik (Author), Rajko Vidrih (Reviewer), Nataša Poklar Ulrih (Mentor), Damijan Miklavčič (Co-mentor)

Abstract

V okviru magistrskega dela smo preverjali ali z uporabo pulzirajočega električnega polja lahko zvišamo prehransko vrednost lanenega olja. V ta namen smo uporabili prototipno stiskalnico, ki je delovala tudi kot elektroporacijska komora s pomičnimi elektrodami. V stisnjenem lanenem olju smo določili vsebnost vode, maščob, maščobnokislinsko sestavo, vrednost peroksidnega števila, antioksidativni potencial izražen kot koncentracija troloks ekvivalenta ter določili barvo olja v primerjavi s kontrolnim vzorcem. Ob pridobivanju olja z uporabo pulzirajočega električnega pulza smo določili za 16 % večji izkoristek stiskanja. Delež posameznih maščobnih kislin (MK) se bistveno ni razlikoval med vzorcem in kontrolo. Olje je vsebovalo največji delež α-linolenske MK, in sicer približno 46 %. Po deležu sta ji sledila oleinska MK in linolna MK. Oba vzorca sta bila v zakonsko določenih mejah vrednosti peroksidnega števila, vendar je bila vrednost peroksidnega števila vzorca pridobljenega z elektroporacijo statično značilno nižja v primerjavi s kontrolo. Nižje peroksidno število pomeni nižjo stopnjo primarne oksidacije. Vzorec pridobljen z elektroporacijo je bil tudi nekoliko bolj rumenkaste barve, kar lahko pripišemo višji koncentraciji luteina. Z uporabo elektroporacije se antioksidativni potencial olja zviša za 11 % v primerjavi s kontrolnim vzorcem. Ob uporabi parametrov elektroporacije z nižjim vnosom energije smo opazili padec antioksidativnega potenciala. Olje pridobljeno z elektroporacijo ima višjo prehransko vrednost. Za dodatno potrditev te teze bi morali uporabiti stiskalnico, z večjo komoro in večjo možnostjo obremenitve. Tako bi lahko pridobili večjo količino vzorca in izvedli dodatne analize s področja oksidativne stabilnosti ter določili vsebnost različnih sekundarnih spojin s HPLC analizo.

Keywords

lan;laneno olje;lanena semena;elektroporacija;PEF;pulzirajoče električno polje;prehranska vrednost;večkrat nenasičene maščobne kisline;AOP;antioksidativni potencial;peroksidno število;izkoristek;DPPH;oksidacija;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [U. Jedlovčnik]
UDC: 641.1:665.345.4:577.352
COBISS: 56667139 Link will open in a new window
Views: 409
Downloads: 75
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Other data

Secondary language: English
Secondary title: Increasing nutritional value of linseed oil by pulsed electric field
Secondary abstract: As part of our master's thesis, we tested whether the nutritional value of flaxseed oil can be increased by using pulsed electric field. For this purpose we used a prototype press, which also served as an electroporation chamber with movable electrodes. In so pressed flaxseed oil we determined the water and fat content, the fatty acid composition, the peroxide number, the antioxidant potential expressed as trolox equivalent concentration, and determined the color of the oil in comparison with the control sample. When oil was extracted by means of a pulsed electric field, we observed an increase in yield of 16% compared to the control sample. The percentage of the individual fatty acids did not differ significantly between sample and control. The oil contained the highest amount of alpha-linolenic acid with about 46 %. This was followed by oleic acid and linoleic acid. Both samples were within the legal limits of the peroxide number, but the value of the peroxide sample obtained by electroporation was statically significantly lower compared to the control. Lower peroxide value means lower level of primary oxidation. The sample obtained by electroporation was also slightly more yellowish in color, which can be attributed to the higher concentration of lutein. The use of electroporation increased the antioxidant potential of the oil, expressed as concentration of the trolox equivalent, by 11% compared to the control sample. The use of electroporation parameters with lower energy input resulted in a decrease of the antioxidative potential. Oil obtained by electroporation has a higher nutritional value, but for further confirmation of the thesis, we would need to use bigger press chamber that would whitstood a greater load. Thus we would obtain a larger sample volume and perform additional oxidtative stability analyzes. We would also determine the content fo various secondary compounds by HPLC analysis.
Secondary keywords: linseed;linseed oil;flaxseed;flaxseed oil;PUFA;electroporation;PEF;pulsed electric field;nutritional value;AOP;antioxidant potential;peroxide value;yield;DPPH;oxidation;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: XI, 59 f.
ID: 12684767