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The objective of this study was to establish the effects of chestnut tannin extract or vitamin E added to linseed oil-enriched diets on growth performance, meat quality, and intestinal morphology of broiler chickens. A total of 240 day-old Ross 308 male broiler chicks were included in trial. 5% of cold-pressed linseed oil was included in finisher diets (21–40 days), and three feeding treatments with four replicates were formed: finisher without additives finisher + 200 IU vitamin E/kg finisher + 500 mg/kg of chestnut wood tannin extract. No significant influence of treatments was established on body weight or feed conversion ratio. A negative effect on feed intake (p < 0.05) was found in the vitamin E group. The addition of vitamin E increased the dressing percentage (p < 0.05) and increased the breast meat yield (p < 0.01) compared to the control group. No significant effects were found on the water holding capacity or pH of breast meat. The highest level of AST (p < 0.01) and ALT (p < 0.05) was recorded in vitamin E group. The addition of chestnut tannin extract in feed increased villus height, villus height: crypt depth ratio, and villus area compared to the other two groups (p < 0.05). It can be concluded that vitamin E supplementation improves carcass percentage and breast meat yield, while chestnut tannins improve the intestinal morphology of broiler chickens when added to oil-enriched diets.The objective of this study was to establish the effects of chestnut tannin extract or vitamin E added to linseed oil-enriched diets on growth performance, meat quality, and intestinal morphology of broiler chickens. A total of 240 day-old Ross 308 male broiler chicks were included in trial. 5% of cold-pressed linseed oil was included in finisher diets (21–40 days), and three feeding treatments with four replicates were formed: finisher without additives finisher + 200 IU vitamin E/kg finisher + 500 mg/kg of chestnut wood tannin extract. No significant influence of treatments was established on body weight or feed conversion ratio. A negative effect on feed intake (p < 0.05) was found in the vitamin E group. The addition of vitamin E increased the dressing percentage (p < 0.05) and increased the breast meat yield (p < 0.01) compared to the control group. No significant effects were found on the water holding capacity or pH of breast meat. The highest level of AST (p < 0.01) and ALT (p < 0.05) was recorded in vitamin E group. The addition of chestnut tannin extract in feed increased villus height, villus height: crypt depth ratio, and villus area compared to the other two groups (p < 0.05). It can be concluded that vitamin E supplementation improves carcass percentage and breast meat yield, while chestnut tannins improve the intestinal morphology of broiler chickens when added to oil-enriched diets.

Atopijski dermatitis je kronična, nenalezljiva vnetna bolezen kože, ki jo spremljajo srbečica in ponavljajoče ekcematozne lezije. Za bolnike je pomembna redna in pravilna nega kože, ključnega pomena pa je ustrezno zdravljenje, usmerjeno v obvladovanje in preprečevanje vnetja in srbenja. Prvo izbiro v okviru lokalnega zdravljenja atopijskega dermatitisa predstavljajo lokalni kortikosteroidi, vgrajeni v klasične farmacevtske oblike kot so kreme in mazila. Z raziskovalnim delom smo želeli doprinesti k izboljšanemu zdravljenju atopijskega dermatitisa z vgradnjo betametazondipropionata v sodobne dostavne sisteme, in sicer liotropne tekoče kristale. Slednji so izredno ugodni za dermalen nanos zaradi svoje specifične mikrostrukture. Obenem je bil ključnega pomena tudi izbor pomožnih snovi, pri čemer smo kot oljno fazo izbrali laneno ali konopljino olje zaradi visoke vsebnosti esencialnih maščobnih kislin s protivnetnim delovanjem, kar je ugodno za atopično kožo, emulgatorska faza je bila sestavljena iz biokompatibilnih površinsko aktivnih snovi, ki spodbujajo nastanek liotropnih tekočih kristalov, in sicer iz lecitina v kombinaciji s Tween 80 ali Montanov 68, hidrofilno fazo pa je predstavljala voda. V okviru eksperimentalnega dela smo z izdelavo (psevdo)trikomponentnih diagramov na podlagi organoleptičnih lastnosti opredelili področja nastanka tekočih kristalov za štiri različne kombinacije oljne faze in zmesi površinsko aktivnih snovi. Za nadaljnje vrednotenje smo izbrali vzorce na razredčitveni premici (tj. pri različnih deležih vode) s konstantnim razmerjem površinsko aktivnih snovi in olja 6/4 in jih z in brez vgrajenega betametazondiproprionata ovrednotili s polarizacijsko mikroskopijo. Za vzorce s Tween 80 smo po celotni razredčitveni premici potrdili nastanek lamelarnih tekočih kristalov, medtem ko smo pri Montanov 68 nastanek lamelarnih mezofaz potrdili zgolj pri določenih vzorcih v odvisnosti od deleža vodne faze. Oljna faza in tudi vgradnja zdravilne učinkovine ni vplivala na nastanek lamelarnih tekočih kristalov. V okviru nadaljnje reološke analize pa smo ugotovili, da se vgradnja zdravilne učinkovine odraža v spremenjenih vrednosti viskoznosti in dinamičnih modulov v primeru vzorcev s Tween 80, v vzorcih z Montanov 68 pa ni prišlo do bistvenih sprememb. Vrednotenje mikrostrukture smo izvedli pri sobni temperaturi (25 °C), pri temperaturi kože (32 °C) in telesni temperaturi (37 °C), pri čemer smo s polarizacijsko mikroskopijo potrdili, da se mikrostruktura ohranja tudi pri višjih temperaturah, medtem ko smo v primeru določenih vzorcev zaznali temperaturno odvisne spremembe viskoznosti. Zaključili smo, da so novo razviti liotropni tekoči kristali primerni za vgradnjo betametazondiproprionata in predstavljajo obetaven dostavni sistem za zdravljenje atopijskega dermatitisa. Atopic dermatitis is a chronic, non-infectious inflammatory skin disease accompanied by itching and recurrent eczematous lesions. Treatment is aimed at controlling and preventing inflammation and itching of the skin, also, regular, and proper skin care is of key importance. The first choice for the local treatment of atopic dermatitis are corticosteroids incorporated into classic pharmaceutical dosage forms such as creams and ointments. Therefore, the objective of our study was to contribute to the improved treatment of atopic dermatitis by incorporating betamethasone dipropionate into modern delivery systems, namely lyotropic liquid crystals. The latter are extremely favorable for dermal application due to their specific microstructure. In addition, the choice of excipients was crucial, with flaxseed or hemp oil being chosen as the oil phase due to its high content of essential fatty acids with anti-inflammatory action being beneficial for atopic skin, while the emulsifier phase consisted of biocompatible surfactants that promote the formation of lyotropic liquid crystals, namely lecithin in combination with Tween 80 or Montanov 68. Water was chosen as the hydrophilic phase. Within the experimental work, the areas of liquid crystal were determined based on organoleptical evaluation for four different combinations of oil phase and mixtures of surfactants by (pseudo)ternary phase diagrams construction. Selected samples (with and without incorporated betamethasone diproprionate) on the dilution line (i.e., at different water proportions) with a constant ratio of surfactants and oil phase 6/4 were used for further microstructure evaluation by polarization microscopy. For samples with Tween 80, the formation of lamellar liquid crystals was confirmed along the entire dilution line, while for Montanov 68 the formation of lamellar mesophases was confirmed only for specific samples depending on the proportions of the aqueous phase. The oil phase as well as the incorporation of the active substance did not affect the formation of lamellar liquid crystals. In the framework of further rheological analysis, we found that the incorporation of the active substance is reflected in the changed values of viscosity and dynamic modules in the case of samples with Tween 80. However, there were no significant changes in the samples with Montanov 68. Evaluation of the microstructure was performed at room temperature (25 °C), skin temperature (32 °C) and body temperature (37 °C), and the microstructure was maintained even at higher temperatures as confirmed by polarization, while temperature-dependent changes in viscosity were detected in case of certain samples. To conclude, the newly developed lyotropic liquid crystals are suitable for the incorporation of betamethasone diproprionate and represent a promising drug delivery system for the treatment of atopic dermatitis.

In a previous study, we examined the synergistic effects of the dietary supranutritional supplementation with vitamin E, vitamin C, and Se on the in vivo antioxidative status of broilers under conditions of dietary oxidative stress induced by feeding a diet high in n-3 PUFA. In this study, we examined the effect of their inclusion on the quality characteristics and oxidative stability of raw or cooked meat, both fresh or after a long-term frozen storage. Four hundred 21-day-old Ross 308 male broilers were allocated to 5 experimental groups fed 5% linseed oil-enriched finisher diets (days 21 to 40): Cont (recommended levels of vitamin E, C, and selenium), +E (200 IU vitamin E/kg feed), +C (250 mg vitamin C/kg feed), +Se (0.2 mg selenium/kg feed), or +ECSe (concentrations as in the sole supplementation, combined). Animal performance and carcass characteristics were monitored at the age of 40 D. Breast meat samples of 12 chickens per group were analysed fresh, fresh after frozen storage, cooked fresh, and cooked after frozen storage (2 × 2 factorial design) for parameters of meat quality (water-holding capacity—WHC, pH, and color) and oxidative stability (concentrations of vitamin E, malondialdehyde—MDA, antioxidant capacity of the water-soluble compounds—ACW, and fatty acid composition). Vitamin E alone (+E) and combined with Se and vitamin C (+ECSe) increased the α-tocopherol concentration in breast muscle, and showed similar protective effects against lipid peroxidation measured as MDA regardless of the frozen storage or cooking. The sole supplementation of vitamin C or selenium showed no effects on the meat quality parameters. In conclusion, the dietary supranutritional inclusion of vitamin E inhibited the lipid peroxidation in fresh, frozen stored, cooked fresh, and frozen stored meat in broilers fed with diets rich in n-3 PUFAs. Even though no clear synergistic effects of the supranutritional supplementation of vitamin C and Se with vitamin E were detected, their dietary inclusion did not negatively affect broilers carcass and meat quality parameters.

Bakterijska adhezija na površinah in pozneje nastanek biofilma predstavljata glavni vzrok kroničnih okužb z negativnim vplivom na zdravje ljudi. S tem izzivom se srečujemo tudi pri izbiri in izdelavi pohištva, kjer stremimo k razvoju izdelkov s takšnimi površinami, na katere naj se bakterije ali drugi mikroorganizmi praviloma ne bi oprijemali. Predmet naše raziskave je bil testirati izbrana premazna sredstva za les (laneno olje, vodna lazura, nitrocelulozni lak, nanopremaz) na adhezijo bakterij vrste Pseudomonas aeruginosa, kjer smo kot testno površino uporabili vezano bukovo ploščo. Topografijo testne površine in število oprijetih bakterij P. aeruginosa smo opazovali z vrstičnim elektronskim mikroskopom (SEM) in na posnetkih SEM identificirali in prešteli bakterije. Rezultati nakazujejo, da se je največje število bakterij oprijelo na površini, premazani z lanenim oljem. Za potrditev in pridobitev relevantnih rezultatov bodo v prihodnosti potrebne obširnejše in bolj poglobljene študije.

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. 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.

V okviru diplomske naloge smo z metodo Rancimat v lanenem in sončničnem olju preverjali antioksidativen učinek izbranih biogenih aminov (spermina, spermidina in tiramina) v koncentraciji 1 mmol/kg, antioksidativen učinek spermina v koncentracijah 1 mmol/kg, 0,4 mmol/kg in 0,1 mmol/kg ter rezultate primerjali z učinkom izbranih antioksidantov (alfa-tokoferol, gama-tokoferol in BHT) v koncentraciji 1 mmol/kg. Vsi dodatki so podaljšali obstojnost olja. Laneno olje oksidira hitreje kot sončnično, saj ima večji delež večkrat nenasičenih maščobnih kislin, predvsem alfa-linolenske. Ugotovili smo, da so biogeni amini pri koncentraciji 1 mmol/kg boljši antioksidanti kot izbrani fenoli in BHT. Najmočnejši antioksidativni učinek smo določili za spermin, ki je upočasnil oksidacijo olj tudi pri najmanjši dodani koncentraciji 0,1 mmol/kg. Te ugotovitve bi lahko imele praktično uporabnost v živilski industriji, vedno več raziskav se namreč osredotoča na iskanje naravnih spojin z antioksidativnim učinkom. In the Bachelor thesis we tested the antioxidative effect of the biogenic amines (spermine, spermidine, tiramine) at the concentration of 1 mmol/kg, antioxidative effect of spermine at the concentrations of 1 mmol/kg, 0,4 mmol/kg, 0,1 mmol/kg and compared the results with the effect of alpha-tocopherol, gamma-tocopherol and BHT at the concentration of 1 mmol/kg in flaxseed and sunflower oil with the Rancimat method. All additions resulted in improved oil stability. Flaxseed oil oxidizes faster than sunflower oil because it contains more polyunsaturated fatty acids, especially alpha-linolenic acid. We concluded that biogenic amines are better antioxidants compared to phenolic compounds alpha- and gamma-tocopherol and BHT at 1 mmol/kg concentration. Spermine was determined to be the strongest antioxidant used in the experiment and it shows the antioxidative effect even at the concentration of 0,1 mmol/kg. Those findings could have the practical implications in food technology as recently many research is focused on finding natural compounds with antioxidative effect.

Trans-resveratrol (RES) v etanolni raztopini na svetlobi ni stabilen, saj zelo hitro začne prehajati iz trans- v cis-izomer. V raziskavi smo preučevali topnost in stabilnost trans-RES v oljih ter njegov vpliv na obstojnost olj. Ugotovili smo, da je trans-RES v gliceril trioktanoatu (TAG) dobro topen, v sončničnem olju (SON) pa nekoliko manj. Njegova temperaturna stabilnost v izbranih oljih je dobra, saj se v lanenem olju (LAN) pri temperaturi 60 °C ohrani pet dni, v SON pa vsaj deset dni. V TAG z dodatkom metil-linolenata (M-L) in trans-RES se je slednji izkazal kot učinkovit antioksidant, saj je raztopina brez dodanega trans-RES bistveno hitreje oksidirala. V TAG smo ugotavljali tudi antioksidativno učinkovitost (AOU) dodanega α-tokoferola (TOKO) in njegove kombinacije z trans-RES. α-TOKO je boljši antioksidant kot trans-RES, sinergističnega učinka med omenjenima antioksidantoma pa nismo opazili. Podobno tudi v SON in LAN ni bilo zaznanega sinergističniga učinka trans-RES z naravno prisotnimi antioksidanti - peroksidacija v oljih z dodatkom trans-RES in brez njega je potekala skoraj enako hitro (dan 10 – peroksidno število SON in SON z dodatkom RES – 58, LAN – 310 ter LAN z dodatkom RES – 277). Pri raztapljanju ekstrakta olupka korenine japonskega dresnika v oljih in TAG smo ugotovili, da so se poleg trans-RES raztopili tudi nekateri drugi antioksidanti, ki pomembno prispevajo k AOU, določeni z radikalom DPPH. When exposed to light, trans- resveratrol (RES) dissolved in ethanol is not stable as it isomerises into cis- isomer. In this research, we examined the solubility and stability of trans-RES in oils and its influence on lipid stability. Trans-RES was better soluble in glyceril trioctanoate (TAG) than in sunflower oil (SON). Temperature stability of trans-RES in edible oils was good in flaxseed oil (LAN) it was preserved for 5 days and in SON at least 10 days upon incubation at 60 °C. In TAG with added methyl-linolenate (M-L) trans-RES was an efficient antioxidant – the solution with only TAG and M-L peroxidised faster. We also examined antioxidant capacity (AOC) of TAG with α-tocopherol (TOKO) and its combination with trans-RES. α-TOKO was better antioxidant, while the synergistic effect between α-TOKO and RES was not observed. Likewise, the synergistic effect among trans-RES and other antioxidants already present in LAN and SON was not observed. Peroxidation rate of oils with or without trans-RES was similar (day 10 – peroxide value SON and SON with addition of RES – 58, LAN – 310 and LAN with addition of RES – 277). When root peel extract of Fallopia japonica was dissolved in oils and TAG, other antioxidants apart from trans-RES were also dissolved. They significantly contributed to the AOC determined with DPPH radical.

The reactivity of tocopherols with 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied in model systems in order to establish a method for quantifying vitamin E in plant oils. The method was optimized with respect to solvent composition of the assay medium, which has a large influence on the course of reaction of tocopherols with DPPH. The rate of reaction of α-tocopherol with DPPH is higher than that of γ-tocopherol in both protic and aprotic solvents. In ethyl acetate, routinely applied for the analysis of antioxidant potential (AOP) of plant oils, reactions of tocopherols with DPPH are slower and concentration of tocopherols in the assay has a large influence on their molar reactivity. In 2-propanol, however, two electrons are exchanged for both α- and γ-tocopherols, independent of their concentration. 2-propanol is not toxic and is fully compatible with polypropylene labware. The chromatographically determined content of tocopherols and their molar reactivity in the DPPH assay reveal that only tocopherols contribute to the AOP of sunflower oil, whereas the contribution of tocopherols to the AOP of linseed oil is 75%. The DPPH assay in 2-propanol can be applied for rapid and cheap estimation of vitamin E content in plant oils where tocopherols are major antioxidants.

Cilj dela je bil opredeliti prehransko vrednost, tehnološko kakovost in senzorične lastnosti neobičajnih olj: arašidovo, arganovo, črne kumine, gorčično, grozdnih pešk, inca inchi, kokosovo, konopljino, laneno, makovo, oljne ogrščice, orehovo, ričkovo olje in ghee maslo. Ocenili smo 27 vzorcev neobičajnih olj. Prehransko vrednost in tehnološko kakovost smo ocenili z analizami maščobnokislinske sestave (MK) ter peroksidnega in kislinskega števila. Največ α-linolenske kisline vsebujejo laneno, inca inchi ter ričkovo olje. Olja bogata z linolno kislino pa so makovo, grozdnih pešk, orehovo, črne kumine, arašidovo in konopljino olje, ki imajo neugodno razmerje n-6/n-3. Najbolj ugodno razmerje n-6/n-3 pa imajo olje oljne ogrščice, konopljino, gorčično in orehovo olje. Kokosovo olje in ghee maslo, glede na MK sestavo in nevarnosti vsebnosti oksidiranega holesterola, nista priporočljiva za pogosto uporabo, oz. sta priporočljiva "le za zelo zmerno uporabo". Priporočeni MK sestavi so se najbolj približala olje oljne ogrščice, gorčično (brez eruka kisline) in ričkovo olje, ki imajo tudi idealno razmerje n-6/n-3 MK. Ugotovili smo, da se naši rezultati z literaturnimi podatki po večini ujemajo, razen eden od vzorcev ričkovega ter gorčičnega olja, ki vsebujeta preveliko količino eruka kisline. Določili smo tudi stabilnost olj in ugotovili, da so olja najbolj primerna za termično obdelavo pri visokih T kokosovo, oljne ogrščice, gorčično in arašidovo olje. Senzorične lastnosti vseh vzorcev smo ocenili s senzoričnim panelom in ugotovili, da so ocenjevalci najbolje ocenili ghee maslo, kokosovo ter orehovo olje. The main purpose of the master's work was to determine the nutritional value, technological quality and sensory properties of 14 unconventional oils: peanut, argan, black cumin, mustard, grape seed, inca inchi, coconut, hemp, linseed, poppy, rapeseed, walnut, Camelina sativa oil and ghee butter. We evaluated 27 samples of unconventional oils. The nutritional value and technological quality was assessed by analysis of the fatty acid (FA) composition, the peroxide and the acid number. Oils with the highest α-linolenic acid content are linseed, inca inchi and Camelina sativa oil. Oils rich in linoleic acid are poppy seed, grape seed, walnut, black cumin, peanut and hemp seed oil, with an unfavourable ratio of n-6 / n-3. The most favourable ratio of n-6 / n-3 have rapeseed, hemp seed, mustard and walnut oil. Coconut oil and ghee butter, considering the FA composition and the risk of oxidized cholesterol content, are not recommended for frequent use or they are "only for very modern use". Oils close to the ideal FA composition are rapeseed oil, followed by mustard oil (without erucic acid) and camelina oil, which also have the ideal ratio of n-3 / n-6 fatty acids. We have found that our results mostly matched with the data literature, except one sample of canola and mustard oil, which contained excessive amounts of erucic acid. We also determined the stability of oils and observed that oils suitable for thermal treatment at high T are coconut oil, followed by rapeseed, mustard and peanut oil. Finally, we have made the sensory evaluation of all oil samples with sensory panel, which the most preferred ghee butter, coconut and walnut oil.

Antioksidanti so snovi, ki preprečujejo oksidacijo drugih molekul. Najpogosteje jih najdemo v različnih živilih, predvsem v sadju in zelenjavi. Velikokrat jih dodamo živilom kot prehranska dopolnila. Najpomembnejši antioksidanti v rastlinskih oljih so predvsem različni analogi vitamina E, tokoferoli in tokotrienoli. Nekatera nerafinirana rastlinska olja pa vsebujejo tudi druge, bolj polarne antioksidante, kot so sezamol, pinoresinol, tirozol in hidroksitirozol ter njihove derivate, kjer se olja ekstrahirajo skupaj z vitaminom E. Namen magistrske naloge je bil določitev antioksidativnega potenciala različnih rastlinskih olj v polarni in nepolarni frakciji z DPPH v različnih topilih. DPPH metoda je ena najpogostejših metod za določanje antioksidativnega potenciala (AOP) olj. AOP smo analizirali v etilacetatu in mešanici alkoholov, ki je vsebovala kislinsko bazni par. Pri svojem delu smo uporabljali oljčno, sezamovo, laneno in sončnično olje. Ugotovili smo, da je bil prispevek polarne frakcije k AOP večji v oljčnem in sezamovem olju kot v lanenem in sončničnem olju. Prav tako je iz naših rezultatov razvidno, da je AOP polarne in nepolarne frakcije olj aditiven s skupnim AOP olj. DPHH metodo v mešanici alkoholov in kislinsko baznega para lahko uporabimo za hitro oceno vsebnosti tokoferolov v sončničnem in lanenem olju. Antioxidants are substances, that prevent oxidization of other molecules. They can be found in various foods most commonly in vegetables and fruits. They are often added to food as food additives. The most important antioxidants in plant oils are various analogs of vitamin E, tocopherols and tocotrienols. Some unrefined plant oils also contain some other, more polar antioxidants, such as sesamol, pinoresinol, tyrosol and hydroxytyrosol and their derivates, that are extracted along with vitamin E into the oils. The aim of this master thesis was to determine the antioxidative potencial of different plant oils in polar and non-polar fraction with DPPH in various solvents. DPPH method is one of the most frequent methods for evaluation of antioxidant potential (AOP) of oils. AOP was analyzed in ethylacetate and in the mixture of alcohols containing acid base pair. We found out, that the contribution of polar fraction to the AOP was greater in olive and sesame oil than in linseed and sunflower oil. Our data also show, that the sum of AOP for polar and non-polar fraction is the same as the AOP of unfractionated oil. DPPH assay performed in the mixture of alcohols containing acid base pair can be applied for rapid estimation of tocopherol content in sunflower and linseed oils.

This experiment was conducted to investigate the effect of different dietary fatty acids (saturated or polyunsaturated fatty acids) supplementation on the oxidative status and intestinal morphology of adult rabbits (Oryctolagus cuniculus). Twenty-four &ldquo, slovenska kunka&rdquo, rabbits were randomly assigned to two different dietary treatments (12 rabbits per treatment) and fed the experimental diets between 80 and 102 days of age. The palm fat (PALM) diet with 6% palm fat and linseed (LINSEED) diets with 6% linseed oil were used. To evaluate the oxidative status of rabbits, the malondialdehyde concentration in urine and plasma and concentration of water and lipid soluble antioxidants in plasma were measured. The antioxidative capacity of the gastrointestinal tract was evaluated by measuring concentration of water and lipid soluble antioxidants in tissues and contents of the intestine. The histological structure of the small intestine and caecum was analyzed via histomorphometric analysis. No significant differences were found in either of those parameters. In summary, rabbits were exposed to high levels of polyunsaturated fatty acids with a high predisposition to oxidation, but their health and welfare were not endangered.

magistrsko delo

Les kot organski material navadno sam po sebi ni dovolj odporen za uporabo na prostem, kjer je izpostavljen različnim dejavnikom razkroja. Zato ga je treba ustrezno zaščititi. Ena od rešitev je zaščita s hidrofobnimi pripravki, s katerimi poskušamo preprečiti dodatno navlaževanje lesa in ga s tem obvarovati pred glivnim razkrojem. Preučevali smo, kako učinkovito različni hidrofobni pripravki preprečujejo navlaževanje lesa. Iz smrekovine (Picea abies) smo pridobili vzorce, ki smo jih impregnirali z različnimi hidrofobnimi pripravki (rustikal olje, silikonska emulzija, laneno olje, montanski vosek, tungovo olje, itd.). Po impregnaciji in fiksaciji smo impregnirano stran vzorcev potopili v vodo. Navlaževanje vzorcev smo določili v skladu z modificiranim standardom EN 927-5. Vzorce smo potopili v vodo za točno določena časovna obdobja (1, 2, 3, 4 in 7 dni) in jim gravimetrično določili vlažnost. Nekateri hidrofobni pripravki dobro zaščitijo les pred vlago, drugi pa slabše. Med testiranimi hidrofobnimi pripravki se je najbolje obneslo rustikal olje, najslabše pa polietilenski vosek, ki smo ga pred testiranjem segrevali na 145 °C (WE1 50). Wood as organic material is generally not suitable for outdoor applications, as it is susceptible to different factors of decomposition. Thus, it has to be protected properly. One of the solutions is protection with hydrophobic solutions, which limits moisturizing, and therefore, protects it from fungal decomposition. The purpose of this research was to elucidate efficacy of different hydrophobic solutions, and emulsions to reduce or slow down moisturizing. Norway spruce (Pices abies) wood samples were impregnated with different hydrophobic solutions (rustical oil, silicone emulsion, linseed oil, mountain wax, tung oil, etc.). After the impregnation and conditioning, the impregnated part of the samples was exposed to water as prescribed by EN 927-5 standards. After respective periods of submersion, (1, 2, 3, 4 and 7 days) after uptake as gravimetrically determined. Hydrophobic solutions were more or less effective. Among the tested hydrophobic solutions rustical oil exhibited the highest efficacy, while the lowest hydrophobic effect was determined at spruce wood samples impregnated with polyethylene wax emulsions, which were heated above 45 °C prior testing (WE1 50).

S statično analitično metodo smo izmerili ravnotežne topnosti lanenega olja v ogljikovem dioksidu pri temperaturah 30, 50, 70 in 90 °C v območju tlakov od 2,0 do 57,0 MPa. Izmerjeni podatki nam služijo za načrtovanje visokotlačnih procesov. Rezultate smo podali v obliki tabel in grafov v odvisnosti molskega deleža od tlaka pri različnih temperaturah. Analizo vzorcev smo opravili s plinsko kromatografijo. Rezultate plinske kromatografije smo podali v obliki grafa in tabele. With a static analytical method, we measured the equilibrium solubility of linseed oil in the carbon dioxide at temperatures 30, 50, 70 and 90 °C in the range of pressures from 2 to 57 MPa. Measured data are used in the design of high-pressure processes. The results are presented in tables and graphs where molar fractions are presented as a function of the pressure at different temperatures. Analysis of samples was performed by gas chromatography. The results of the GC are presented in the form of graphs and tables.

Namen naloge je bil raziskati kakovosti olja dveh sort lanu, pridelanih v poljskem poskusu na poskusnem posestvu IHPS v Žalcu. Preučevali smo tudi pridelek semena in pridelek olja ter primerjali podatek o vsebnosti olja v semenu oljnic, pridobljen s hladnim stiskanjem olja in z ekstrakcijo. Kakovost olja smo ugotavljali z določitvijo jodnega, kislinskega števila ter maščobno-kislinske sestave. Sorta oljnega lanu Flanders je v primerjavi s sorto Cebeco dosegla primerljiv pridelek in je imela značilno večjo vsebnost olja v semenu, zato je imela posledično tudi (neznačilno) višji pridelek olja. Vsebnost olja, pridobljena s hladnim stiskanjem, se ni bistveno razlikovala od podatka o vsebnosti olja, pridobljenega z ekstrakcijo. Z določitvijo jodnega števila smo potrdili visoko vsebnost nenasičenih maščobnih kislin. Kislinsko število je pri obeh sortah nižje od dovoljene meje za uporabo olja za biodizel. Delež linolenske kisline pri obeh sortah je velik in presega 50%, kar nakazuje močne oksidativne lastnosti lanenega olja obeh sort. Glede na karakteristike olja smo potrdili, da olje ni primerno v namen izdelave biodizla. Poleg tega je pridelek olja pri lanu v svetovnem merilu le polovičen v primerjavi s pridelkom olja na enoto površine pri oljni ogrščici. Laneno olje velja po svetu za zelo kakovosten prehranski dodatek. Tudi v naši raziskavi smo glede na preučevane parametre potrdili, da spada to olje med jedilna olja. Priporoča se zgolj kot prehranski dodatek, saj v večjih količinah lahko povzroča neželene učinke na prebavila. The purpose of this thesis was to explore the quality of two flax varieties that were produced in a field experiment on experimental field of Slovenian Institute of Hop Research and Brewing in Žalec. We studied both the production of seed and the production of oil. We compared the contents of cold pressed oil and of oil gained by extraction. Oil content was significantly higher at variety Flanders compared to variety Cebeco. Variety Flanders achieved higer yield compared to variety Cebeco, but the difference was not significant. Therefore, Flanders had higher oil yield compared to variety Cebeco, but the difference was not significant. The content of oil gained by cold pressing was not essentially different compared to the result gained by extraction. We detected high content of unsaturated fatty acids. The acid value of both varieties was lower that the value which is allowed that specific oil is used for biodiesel. The share of linolenic acid was high at both varieties it exceeded 50%, which indicates oxidising features of both varieties. Given the characteristics of oil, we confirmed that the oil is not suitable for the purpose of manufacturing biodiesel. In addition, the yield of flax oil amounts up to only half of yield worldwide compared to the oil yield gained per unit area of oilseed rape. Linseed oil is the high-quality nutritional supplement known worldwide. On the basis of the parameters, our study confirmed that this oil falls within the category of cooking oils. It is recommended only as a food additive, due to the fact that it can cause gastrointestinal side effects in larger quantities.