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The biomass per plant and total phenolics (TPH) of ethanol extracts of 3 species of thyme, Thymus vulgaris, T. serpyllum,and T. citriodorus, and 3 varieties of basil (Ocimumbasilicum), Genovese, Thai, and Cinnamon, were investigated. All were grown organically. The 2 herbs that showed the greatest biomass were T. citriodorus (26.5 g/plant) and O.basilicum var. Cinnamon (105 g/plant). For these, total flavonoids (TFL), total flavones and flavonols (TFF), and total flavanones and dihydroflavonols (TFDH) were also determined for their ethanol extracts. Furthermore, the antioxidant potential (AOP) and antibacterial activity were determined against foodborne bacteria: Staphylococcus aureus, Listeria monocytogenes, Campylobacter jejuni, and verotoxin-producing Escherichia coli(VTEC). The highest TPH (36 mg chlorogenic acid equivalents per gram of fresh weight) was seen for T. citriodorus collected in 2010. The thyme ethanol extracts contained more TPH and TFL, and their subgroups of TFF and TFDH, than the ethanol extracts from basil, and had AOP comparable to the ethanol extracts from basil, although all of them were lower than the synthetic antioxidant, t-butylated hydroxytoluene. Drying of these herbs decreased TFF and TFDH, while TPH and TFL remained unchanged (for T. citriodorus) or even increased (for Cinnamon basil), and AOP was higher than that of the ethanol extracts from the frozen herbs. The antimicrobial activities of these ethanol extracts depended mainly on the bacterial target. They were weak against gram-negative VTEC, while their effects against C. jejuni, S. aureus, and L. monocytogenes correlated with their TPH and chemical compositions.

V okviru magistrskega dela smo določali vsebnost skupnih fenolnih spojin, skupnih flavonoidov, posameznih skupin flavonoidov in antioksidativni potencial (AOP) cvetnega prahu osmukanca. Zanimal nas je vpliv skladiščenja, toplotne obdelave in načina sušenja cvetnega prahu ter vpliv skladiščenja etanolnih izvlečkov cvetnega prahu na omenjene parametre. Vsebnost fenolnih spojin smo določili spektrofotometrično z uporabo Folin-Ciocalteu reagenta v svežem cvetnem prahu, ki je bil zbran leta 2019, smo določili med 5,7 in 12,4 mg galne kisline/g suhe snovi. AOP smo določili z metodo lovljenja radikala DPPH• in O2•- ter ugotovili, da preiskovani cvetni prah vsebuje dobre lovilce omenjenih radikalov. Dveletno skladiščenje cvetnega prahu (zamrznjenega pri –18 °C in posušenega pri sobni temperaturi) ne vpliva na zmanjšanje vsebnosti fenolnih spojin, vpliva pa na zmanjšanje AOP med skladiščenjem zamrznjenega cvetnega prahu. Toplotna obdelava vpliva na spremembe v vsebnosti skupnih fenolnih spojin pri nekaterih režimih obdelave. Daljši čas toplotne obdelave vpliva na zmanjšanje vsebnosti skupnih flavonoidov. Liofilizacija ne vpliva na zmanjšanje vsebnosti skupnih fenolnih spojin, skupnih flavonoidov in AOP. Skladiščenje izvlečkov cvetnega prahu na svetlobi pri sobni temperaturi (tri mesece) vpliva na zmanjšanje vsebnosti skupnih fenolnih spojin pri večini izvlečkov. Skladiščenje izvlečkov cvetnega prahu v hladilniku (4 - 8 °C tri mesece) pri večini izvlečkov ne vpliva na zmanjšanje vsebnosti skupnih fenolnih spojin. The aim of this thesis was to determine total phenolic and flavonoid content, content of flavonoid subgroups, and antioxidative potential (AOP) of bee pollen. We investigated the influence of storage, heat treatment, and drying method of bee pollen, and the influence of storing bee pollen ethanolic extracts on mentioned parameters. The total phenolic content was determined spectrophotometrically using Folin-Ciocalteu reagent between 5.7 and 12.4 mg gallic acid/g dry matter was determined in fresh bee pollen, collected in year 2019. AOP was determined by the DPPH• and O2•- radical scavenging method and it was found that the investigated bee pollen contains good scavengers of these radicals. Two-year storage of bee pollen (frozen –18 °C and dried at room temperature) does not decrease total phenolic content, but it does decrease AOP of frozen bee pollen. Heat treatment affects the total phenolic content of bee pollen in some treatment regimes. Prolonged heat treatment has the effect of reducing total flavonoid content. Lyophilisation does not decrease the total phenolic content, total flavonoid content and AOP. Storing bee pollen extracts in light at room temperature for three months decreases total phenolic content in most of the extracts. Storing bee pollen extracts in a refrigerator (4 - 8 °C) for three months does not decrease the total phenolic content in most of the extracts.

Raziskali smo, ali se sorte industrijske konoplje razlikujejo glede na vsebnost skupnih fenolnih spojin, flavonoidov, posameznih skupin flavonoidov in antioksidativni potencial (AOP) izvlečkov iz razmaščenih semen. Izvlečke smo pripravili s solventno ekstrakcijo s 70 % (v/v) etanolom. AOP smo določili z metodo lovljenja radikalov DPPH• oz. O2•⠒ in z metodo beljenja β-karotena v emulziji linolne kisline v vodi. Parametri vsebnost fenolnih spojin, flavonoidov, posameznih skupin flavonoidov in AOP so se med sortami razlikovali. Sorti Kompolti hibrid TC in Monoica sta imeli največjo vsebnost skupnih fenolnih spojin, sorta Tiborszallasi je imela največjo vsebnost skupnih in posameznih skupin flavonoidov (flavonov, flavonolov, flavononov in dihidroflavonolov). Največji AOP, ki smo ga določili z metodo lovljenja DPPH•, je imela sorta Tiborszallasi, pri lovljenju O2•⠒ pa sorta Kompolti hibrid TC. Izbira ekstrakcijskega topila in njegova koncentracija sta imeli vpliv na dobit ekstrakcije in AOP. Najučinkovitejše topilo za ekstrakcijo fenolnih spojin in flavonoidov je bil 70 % aceton. Med tremi koncentracijami etanola (50 %, 70 % in 90 %) je bila največja dobit fenolnih spojin pri 70 % etanolu, pri 70 % in 90 % koncentraciji pa največja dobit flavonoidov. Daljši čas ekstrakcije ni povečal dobiti ekstrakcije fenolnih spojin, povečal pa je dobit flavonoidov, posameznih skupin flavonoidov in AOP izvlečkov. Segrevanje razmaščenih semen pri 120 °C je povečalo dobit ekstrakcije fenolnih spojin in skupnih flavonoidov daljši čas segrevanja ni povečal dobiti. Segrevanje razmaščenih semen je pozitivno vplivalo na AOP izvlečkov. We investigated, if variety of idustrial hemp affects the content of total phenolic compounds, flavonoids and its subgropus, and antioxidative potential (AOP) of the extracts, from defatted hemp seeds, prepaired by solvent extraction in 70 % (v/v) ethanol. We determined the AOP by DPPH• and O2•⠒ radical scavenging assays and by β-carotene bleaching assay in emulsion of linoleic acid in water. Hemp variety affected the total phenolic, total flavonoid and its subgroups (flavones, flavonoles, flavonones and dihydroflavonoles) content, and the AOP of the extracts. The highest content of phenolic compounds had Kompolti hibrid TC and Monoica varieties. Tiborszallasi had the highest content of flavonoids and its subgroups and also the highest AOP determined by DPPH• scavenging assay. Kompolti hibrid TC had the highest AOP determined by O2•⠒ radical scavenging assay. The type of extraction solvent and its concentration had a big impact on extraction yeld and the AOP. The most efficient solvent for extraction of total phenolics and flavonoids was 70 % acetone. Considering three ethanol concentrations (50 %, 70 % and 90 %), 70 % ethanol was the most efficient for extraction of phenolic compounds, 70 % and 90 % ethanol was the most efficient for extraction of flavonoid compounds. Prolonged extraction time didn't increase the content of total phenolics, but it increased the content of flavonoids and flavonoid subgroups and the AOP. Heat treatment of defatted seeds at 120 °C increased extraction yield of total phenolic and flavonoid content, while longer heat treatment didn't. Heat treatment had a positive impact on AOP of the extracts.

Uporaba in zanimanje za olje industrijske konoplje (Cannabis sativa L.) se povečuje, saj vsebuje veliko nenasičenih maščobnih kislin in ima specifično sestavo sterolov. Namen magistrske naloge je bil vzpostavitev metode, s katero bi poskušali preveriti, kako lahko na osnovi maščobnokislinske in sterolne sestave konopljinega olja določimo njegovo botanično čistost. Ugotavljali smo tudi, ali lahko na osnovi primerjave sestave med čistim konopljinim oljem in konopljinim oljem z dodatkom drugega olja ugotovimo potvorbe ter kakšne so količine dodatka drugih olj, da povzročijo zaznavno spremembo v sestavi konopljinega olja. Maščobnokislinsko sestavo in sterolno sestavo smo določali s plinsko kromatografijo s plamensko ionizacijskim detektorjem. Na osnovi obeh sestav smo s pomočjo kemometrije pokazali, kako se mešanice olj (potvorjena olja) razlikujejo med seboj in od čistega konopljinega olja. Združeni rezultati regulariziranih diskriminantnih analiz so pokazali, da pri vsebnosti dodanih olj, ki je enaka ali manjša od 5,3 % (w/w), na podlagi sterolne in maščobnokislinske sestave ne moremo ugotoviti, ali gre za potvorbo konopljinega olja. Maščobnokislinska sestava in pa tudi sterolna sestava konopljinega olja se zagotovo spremeni, ko je vsebnost dodanega olja (sončnično, sojino, repično) nad 9,3 % (w/w). The use and interest in industrial hemp oil (Cannabis sativa L.) is increasing as it contains a lot of unsaturated fatty acids and has a specific sterol composition. The purpose of the master's thesis was to establish a method with which we could verify the botanical purity of hemp oil based on its fatty acid and sterol composition. We also examined whether one can recognize forged oil based on the comparison of the compositions of pure hemp oil and hemp oil with the addition of another oil, and what quantities of other oils cause a perceptible change in the composition of hemp oil. The fatty acid and sterol composition were determined by gas chromatography with a flame ionization detector. Based on both compositions, we used chemometry to show how oil mixtures (forged oils) differ from each other and from pure hemp oil. The combined results of the regularized discriminant analyses showed that on the basis of sterol and fatty acid compositions it is no longer possible to determine whether the hemp oil is pure or forged when the added oil content is equal or less than 5,3 % (w/w). The fatty acid as well as the sterol composition of hemp oil certainly changes when the content of added oil (sunflower, soybean, rapeseed) is above 9,3 % (w/w).

Namen diplomske naloge je bil pregledati novejše znanstvene članke o vplivu prisotnih oz. dodanih antioksidantov na kakovost olja. Glede na pregledano literaturo cvrenje povzroča tvorbo številnih nezaželenih produktov, ki so škodljivi in povzročajo žarek okus in vonj. Nastali produkti v olju za cvrenje predstavljajo težavo, ker prehajajo tudi v živilo in s tem lahko zmanjšajo njegovo varnost, kakovost in prehransko vrednost. Stabilnost olja je odvisna predvsem od njegove maščobno kislinske sestave, vsebnosti antioksidantov ter pogojev cvrenja. Večkrat nenasičene maščobne kisline, odsotnost antioksidantov, visoka temperatura in čas cvrenja ter prisotnost kisika in drugih prooksidantov poslabšajo oksidativno stabilnost olja. Antioksidanti za zaščito olja med cvrenjem morajo biti v njem dobro topni in stabilni ob povišani temperaturi. Sintetični antioksidanti so primerni predvsem za zaščito olja v času skladiščenja, le nekateri sintetični antioksidanti so toplotno obstojni in primerni za uporabo v oljih za cvrenje. Med naravnimi antioksidanti so najučinkovitejši fenoli in polifenoli. Njihovo topnost in uporabnost v oljih za cvrenje poveča vlaga, ki v olje pride iz živil. Za povečanje topnosti oz. lipofilnosti (poli)fenolov so možne strukturne pretvorbe teh molekul. Za povečanje učinkovitosti predlagajo raziskovalci tudi uporabo zmesi različnih spojin, ki se med seboj dopolnjujejo. The purpose of the graduation thesis was to review the recent scientific literature about the effect of present or added antioxidants on quality of the oil. Based on the reviewed literature, frying causes formation of undesirable products that are harmful to health and cause rancidity. The products formed in frying oil pose a problem because they also pass into the food and thus reduce its safety, quality and nutritional value. Oil stability is mostly dependent on oil fatty acid composition, antioxidant content and frying conditions. Polyunsaturated fatty acids, the absence of antioxidants, temperature and time of frying, the presence of oxygen and other prooxidants all might affect the oxidative stability of oil. For oil protection during frying, antioxidants have to be well soluble and stable at elevated temperatures. Synthetic antioxidants are mainly suitable for protecting oil during storage, though only some synthetic antioxidants are stable at high temperatures and suitable for use in frying oils. Among natural antioxidants the phenols and polyphenols are the most effective. Their usefulness and solubility in frying oils is increased by the moisture that enters the oil from food. To increase the solubility or lipophilicity of (poly) phenols, structural transformations of these molecules are possible. To increase efficiency, researchers also suggest the use of a mixture of different compounds that complement each other.

Priljubljenost špargljev v zadnjih letih narašča, predvsem zaradi njihovega ugodnega vpliva na zdravje človeka. V okviru diplomske naloge smo želeli podati pregled literature s področja bioaktivnih snovi, ki se nahajajo v navadnem šparglju (Asparagus officinalis L.). Naloga zajema seznam in opis bioaktivnih spojin ter njihovih antioksidativnih in fizioloških učinkov. Poglobi se v delovanje različnih sekundarnih metabolitov kot so fenolne spojine, predvsem flavonoidi, fenolne kisline in antociani ter saponini in ostali antioksidanti. Podrobneje obravnava najbolj zastopane spojine, kot sta rutin in protodioscin, vključuje pa tudi v manjših koncentracijah prisotne bioaktivne komponente, kot so glutation, žveplo-vsebujoče spojine, karotenoidi, klorofili, vitamini in minerali. Opisana je tudi primerjava prisotnosti teh spojin med različnimi deli rastline. Naloga predstavi, kako različni načini pridelave in predelave vplivajo na njihovo vsebnost. Opiše vpliv organske in konvencionalne pridelave ter svetlobe in temperature na stabilnost bioaktivnih spojin. Raziskali smo tudi vpliv različnih načinov skladiščenja, kot je modificirana atmosfera, zamrzovanje in hlajenje na vsebnost omenjenih fitokemikalij. Podani so tudi rezultati določanja antoksidativnega potenciala špargljev. The popularity of asparagus has been rising in the recent years due to its positive effect on human health. In this graduation thesis we wanted to put forward a comprehensive review of literature from the field of bioactive compounds, that are found in the asparagus plant (Asparagus officinalis L.). This thesis includes a list and descriptions of bioactive compounds and their antioxidant and physiological effects. It dives deeper into the function of different secondary metabolites like phenolic compounds, most importantly flavonoids, phenolic acids and anthocyanidins but also includes saponins and other antioxidants. It elaborates on the most abundant compounds such as rutin and protodioscin in addition to those less represented, such as glutation, sulphur-containing compounds, carotenoids, chlorophylls, vitamins and minerals. Furthermore, it compares the content of these compounds in different parts of the plant. This thesis presents how different cultivation systems and processing methods affect bioactive compound concentrations. It focuses on the effects of organic and conventional cultivation along with light and temperature on their stability. We researched how different storage methods like modified atmosphere, freezing and chilling affect phytochemical concentrations. Results of antioxidant potential assays done on asparagus are presented as well.

The effectiveness of sinapic acid and its derivatives varied with the test system, the type of free radicals and the mechanism of antioxidant activity. It was shown that early response parameters of free radical scavenging are adequate to evaluate differences between antioxidants with comparable endpoint (steady-state) activity. Among selected compounds syringic acid and sinapic acid showed the highest DPPH˙ and O2˙– scavenging activities (determined at steady-state) and the highest ability to inhibit lipid peroxidation in oil. Sinapic acid esters had the highest activities in oil-in-water emulsion and liposome suspension, and ethyl sinapate and propyl sinapate, furthermore, proved to be excellent ˙OH-scavengers. These esters, which were the most lipophilic, had the greatest effects on liposome bilayer thermal and enthalpic destabilisation of the gel state and increased the ordering of the liquid state of the lipids. This dual effect on the lipid bilayer might suggest that the esters initiate the formation of nanodomains with reduced fluidity that can capture hydroperoxides and thus inhibit lipid peroxidation. In the oleogel, the level of inhibition for the more polar compounds, sinapic acid, syringic acid and syringaldehyde, and less polar, 4-vinylsyringol and butyl sinapate, was at the same level, indicating the possible interactions of these less polar compounds with the oil structuring agent in oleogel. This research thus opened a new approach: the possibility of incorporating lipophilic antioxidants to prolong the oxidative stability of oleogel based products. It was shown that white mustard seeds provide excellent source of raw material for the recovery of value-added antioxidant compounds that are effective in preventing lipid peroxidation in systems such as oil and oleogel. Učinkovitost sinapinske kisline in njenih derivatov se razlikuje glede na testni sistem, vrsto prostih radikalov in mehanizem antioksidativnega delovanja. Pokazali smo, da so parametri zgodnjega odziva v lovljenju prostih radikalov ustrezni za ocenjevanje razlik med antioksidanti s primerljivo aktivnostjo v končni točki (v stanju ravnotežja). Med izbranimi spojinami sta siringinska kislina in sinapinska kislina pokazali največjo sposobnost lovljenja O2˙– in DPPH˙radikalov (določeno v stanju ravnotežja) in največjo sposobnost zaviranja peroksidacije lipidov v olju. Estri sinapinske kisline so imeli najvišjo aktivnost v emulziji olja-v-vodi in suspenziji liposomov etil sinapat in propil sinapat pa sta se izkazali za odlična lovilca ˙OH radikalov. Estri, ki so najbolj lipofilni, imajo največji učinek na termično in entalpijsko destabilizacijo stanja gela liposomskega lipidnega dvosloja in povečajo urejenost v tekočem stanju lipidov. Ta dvojni učinek na lipidni dvosloj bi lahko pomenil, da estri sprožijo tvorbo nanodomen z zmanjšano fluidnostjo, ki ujamejo hidroperokside in s tem zavirajo peroksidacijo lipidov. V oleogelu je bila stopnja inhibicije za bolj polarne spojine, sinapinsko kislino, siringinsko kislino in siringaldehid, na isti ravni kot za, 4-vinilsiringol in butil sinapat, kar je pokazalo na možne interakcije teh manj polarnih spojin s sredstvom za strukturiranje olja v oleogel. Ta raziskava je tako odprla nov pristop: možnost vključitve lipofilnih antioksidantov za podaljšanje oksidativne stabilnosti izdelkov na osnovi oleogelov. Pokazali smo, da predstavljajo semena bele gorčice surovino z dodano vrednostjo za pridobivanje antioksidativnih spojin, ki so učinkovite pri preprečevanju peroksidacije lipidov v sistemih, kot sta olje in oleogel.

Konopljina semena, katerih priljubljenost vse bolj narašča, so izvrsten vir hranilnih snovi, esencialnih aminokislin in maščobnih kislin. Vsebujejo tudi nekatere bioaktivne molekule, ki delujejo kot antioksidanti in imajo pozitiven vpliv na zdravje človeka. Cilj diplomske naloge je bil določiti vsebnost fenolnih spojin v različnih sortah konopljinih semen. Prav tako smo določali antioksidativni potencial (AOP) konopljinih semen tako v homogenem (etanol), kot tudi heterogenem (emulzija linolne kisline v vodi) okolju. Semena smo zmleli in razmastili ter ekstrahirali fenolne spojine s 70 % etanolom. Določali smo skupne fenolne spojine s Folin Ciocalteujevo metodo, sposobnost lovljenja prostih radikalov DPPH• in izvedli metodo beljenja ?-karotena v emulziji. Ugotovili smo, da se učinkovitost posameznih antioksidantov razlikuje v različnih sistemih. Prav tako smo prišli do zaključka, da sorte z največ fenolnih spojin nimajo največjega AOP. Hemp seeds are an excellent source of nutrients, such as essential amino acids and fatty acids, and their popularity is growing every day. They also contain bioactive molecules that function as antioxidants and therefore have a positive impact on human health. The aim of graduation thesis was to determine content of total phenolic compounds in different sorts of hemp seeds. We have also examined antioxidant potential (AOP) in different systems: homogeneous (ethanol) and heterogeneous (emulsion of linoleic acid in water) system. Before the extraction of phenolic compounds in 70 % ethanol, hemp seeds were grinded and defatted. We determined total phenolic content with Folin Ciocalteu method, analysed the scavenging activity of free DPPH• radicals and carried out ?-carotene bleaching assay in emulsion. We came to the conclusion that activity of particular antioxidant in homogeneous and heterogeneous system differentiates. Furthermore, hemp seeds with the highest content of phenolic compounds do not have the highest AOP.

V raziskavi smo se osredotočili na raziskovanje vpliva uporabljenih emulgatorjev, obtežil, pogojev homogenizacije ter njihovih kombinacij na lastnosti emulzij za pripravo aromatiziranih pijač. Spremljali smo motnost in stabilnost emulzij, kakor tudi intenzivnost zaznave hlapnih komponent citrusne arome, ki smo jo vključili v emulzijo, s spremljanjem skupnih površin kromatografskih vrhov. Eksperimentalni načrt smo zasnovali s pomočjo programskega orodja Design Expert z metodo načrtovanja poskusa. Analize prve faze poskusa so zajemale merjenje motnosti emulzij s turbidimetrom, merjenje velikosti kapljic emulzij z metodo merjenja delcev in določanje skupnih površin kromatografskih vrhov hlapnih komponent citrusne arome z metodo trdno-fazne mikroekstrakcije plinske faze s plinsko kromatografijo z masno spektrometrijo. Rezultate prve faze smo ovrednotili z analizo variance (p = 0,05) in HSD testom. Glede na rezultate smo izbrali osem kombinacij, ki najbolj ustrezajo našim v naprej postavljenim kriterijem. Druga faza raziskave je bila namenjena zoženju izbora najboljših osmih kombinacij in preverjanju stabilnosti emulzij v aromatizirani pijači. Izvedli smo test oblikovanja obroča in senzorični test razvrščanja po intenzivnosti zaznane arome. Rezultati so pokazali tri kombinacije ravni dejavnikov, ki so tekom celotne raziskave najbolje zadostile našim zahtevam po motni, stabilni aromatizirani citrusni pijači z intenzivno citrusno aromo. In the presented study, we focused on studying the influence of different emulsifiers, weighting agents and conditions of homogenization and their combinations on the properties of emulsion, used for making soft drinks. We were monitoring the emulsion turbidity and stability, as well as the detected intensity, through the total surface area of the chromatographic peaks from volatile citrus aroma components, which we used in the emulsion. We designed the experiment using the Design Expert software and the design of experiments method. In the first phase of the experiment, we measured emulsion turbidity using a turbidimeter, emulsion droplet size with the particle size measuring equipment and the total surface area of the chromatographic peaks from volatile citrus aroma components, using the method of solid-phase micro-extraction of the sample headspace, with a gas chromatography with mass spectrometry. We evaluated the first phase results, using analysis of variance test (p = 0.05) and HSD test. Based on these results we chose eight combinations that best suited our predefined criteria. The second phase of the study was aimed at further narrowing the selection of the chosen eight combinations and verifying the stability of the emulsions in a soft drink. We carried out a simple ringing test and a sensory ranking test where we asked the assessors to rank the samples according to the perceived intensity of the citrus aroma. The results of the study showed three different combinations of the used emulsifiers, weighting agents and conditions of homogenization that best met our requirements for a stable, cloudy soft drink with an intense citrus aroma.

V okviru magistrskega dela smo določili vsebnost trans maščobnih kislin (TMK) v 102 vzorcih različnih živilskih izdelkov, ki so prisotni na slovenskem tržišču. Vzorce smo razporedili v 10 skupin (jušni koncentrati, sladki namazi, instant kavni napitki, čokoladni izdelki, slani prigrizki, sladoledi, rastlinski nadomestki smetan, ocvrt krompirček, dunajski zrezki, hamburgerji) in jim določili maščobnokislinsko (MK) sestavo po AOAC 966.06 metodi s pomočjo plinske kromatografije ob uporabi in situ transesterifikacije. Med vsemi preiskovanimi vzorci je bilo 18 takšnih, v katerih delež TMK presega 2 % od skupnih maščob. To so izdelki, ki sodijo med slane prigrizke, jušne koncentrate in sladolede. Med vsemi analiziranimi skupinami živil vsebujejo največ TMK slani prigrizki. Ugotovili smo, da sedem od skupno desetih skupin vzorcev (jušni koncentrati, slani prigrizki, instant kavni napitki, hamburgerji, sladoledi, rastlinski nadomestki smetan in čokoladni izdelki) vsebuje več trans-C18:1 MK kot pa trans-C18:2. Jušni koncentrati, čokoladni izdelki in slani prigrizki vsebujejo največ t10-C18:1 in t9-C18:1, ki ju najdemo v delno hidrogeniranih rastlinskih oljih. Delež t11-C18:1 pa je najvišji v skupinah hamburgerji in sladoledi. V skupinah ocvrt krompirček in dunajski zrezki smo analizirali največ izomere t9,c12-C18:2, ki nastaja v visokih koncentracijah pri rafinaciji in cvrenju. Skupini instant kavni napitki in rastlinski nadomestki smetan sta se izkazali za najbolj aterogeni in trombogeni skupini živil. The purpose of this MSc thesis was to determine the content of trans fatty acid (TFA) in 102 samples of selected Slovenian supermarket foods. Samples were divided into 10 groups (instant soups, chocolate spreads, instant coffee drinks, chocolate products, salty snacks, ice creams, vegetable whipped creams, French fries, Wiener schnitzels, hamburgers). The fatty acid (FA) composition was determined according to AOAC 966.0 with method in situ transesterification and gas chromatography procedure. The content of TFA exceeded the maximum reference value (below 2 % of TFA) in 18 samples (salty snacks, instant soups and ice creams). Among all the analysed foods, samples in group salted snacks had the highest content of TFA. Most groups of food contained more trans-C18: 1 than trans-C18:2. Based on the results, we found that instant soups, chocolate products and salty snacks contained the highest amount of t10-C18:1 and t9-C18:1. Both of these FA can be found in partially hydrogenated vegetable oils. Group of hamburgers and ice creams on the other hand had the highest content of t11-C18:1. In group of French fries and Wiener schnitzels the highest content of t9,c12-C18:2 was found because this products are prepared by frying food in oil at high temperatures. Instant coffee drinks and vegetable whipped creams proved to be the most atherogenic and thrombogenic food group due to their high content of saturated fatty acids.

Namen magistrske naloge je bil določiti vsebnost skupnih fenolnih spojin, skupnih flavonoidov ter posameznih skupin flavonoidov in ugotoviti antioksidativni potencial (AOP) cvetnega prahu osmukanca. Zanimal nas je vpliv shranjevanja in sušenja cvetnega prahu na preiskovane lastnosti. Izvlečke fenolnih spojin smo pripravili s solventno ekstrakcijo z uporabo 96 % oz. 60 % etanola. AOP smo določili z metodo lovljenja prostega radikala DPPH∙ in z metodo beljenja β-karotena, ki temelji na sposobnosti zaviranja lipidne oksidacije v emulziji. V svežem cvetnem prahu osmukancu, kjer smo izvedli ekstrakcijo s 96 % etanolom, smo določili vsebnost skupnih fenolnih spojin 6-13 mg galne kisline/g suhe snovi in vsebnost flavonoidov 5-13 mg rutina/g suhe snovi. Izvlečki, ki smo jih pridobili s 96 % etanolom, so vsebovali manj skupnih fenolnih spojin in več skupnih flavonoidov od izvlečkov, pridobljenih s 60 % etanolom. Med skladiščenjem svežega cvetnega prahu osmukanca v hladilniku, se vsebnost skupnih fenolnih spojin ne spremeni, zmanjša se vsebnost skupnih flavonoidov. Med sušenjem se zmanjša vsebnost skupnih fenolnih spojin, predvsem flavonoidov. Eden od vzorcev je pokazal AOP, primerljiv z AOP galne kisline, ostali vzorci so bili slabši lovilci DPPH∙. V emulziji izvlečki cvetnega prahu osmukanca, ki smo jih pripravili s 96 % etanolom, kažejo večjo učinkovitost od izvlečkov, pripravljenih s 60 % etanolom. Izvlečki so v emulziji pokazali učinkovitost, primerljivo s sintetičnim antioksidantom butiliranim hidroksitoluenom. The purpose of this graduation thesis was to determine total phenolic content, total flavonoid content and individual groups of flavonoids, and to determine the antioxidative potential (AOP) of bee pollen. The extracts of phenolic compounds were prepared by the solvent extraction with 96 % and 60 % ethanol. AOP was determined with the DPPH∙ radical scavenging method and the method of bleaching β-carotene which is based on the ability to inhibit lipid oxidation in the emulsion. In fresh bee pollen where extraction with 96 % ethanol was used we determined the total phenolic content of 6-13 mg gallic acid/g of dry matter and total flavonoid content of 5-13 of rutin/g of dry matter. The extracts obtained with 96 % ethanol, contained less total phenolic compounds and more total flavonoids than the extracts obtained with 60 % ethanol. During storage of bee pollen in the refrigerator, the content of phenolic compounds remained unchanged, the content of total flavonoids decreased. During drying the content of phenolic compounds decreased, especially flavonoids. One of the samples showed AOP, which was comparable to AOP of gallic acid, other samples showed lower DPPH∙ scavenging activity. Extracts prepared with 96 % ethanol were more efficient in emulsion than those prepared with 60 % ethanol. In emulsion the extracts showed efficacy comparable to the synthetic antioxidant butylated hydroxytoluene.

V okviru magistrske naloge smo pripravili oleogele iz sončničnega, oljčnega, žafranikinega, lanenega olja in olja oljne ogrščice. Oljem smo določili maščobnokislinsko sestavo in jodovo število z namenom, da ugotovimo, kako nenasičenost olja vpliva na teksturne lastnosti oleogelov. Teksturni lastnosti, ki smo ju določili, sta trdota in lepljivost. Oleogele smo pripravili tako iz svežih kot iz močno oksidiranih olj in iz olj z dodatkom rožmarinovega izvlečka. Kot oleogelator smo uporabili čebelji vosek pri 1,5 %, 2 %, 3 %, 5 % in 7 % (w/w). Ohlajali smo jih po treh različnih postopkih in jih izpostavili različnim pogojem skladiščenja, da bi ugotovili, kako vsebnost voska, temperatura ohlajanja in shranjevanja vplivajo na teksturne lastnosti oleogelov in sposobnost vezanja olja (OBC). Ugotovili smo, da na teksturne lastnosti oleogelov in OBC vplivajo vsebnost čebeljega voska, temperatura ohlajanja in skladiščenja oleogela in vrsta olja. Preiskovani oleogeli so termoreverzibilni. Stopnjo oksidiranosti olj in oleogelov smo spremljali z določanjem peroksidnega števila. Rožmarinovim izvlečkom v olju oz. v oleogelu smo določili tudi antioksidativni potencial. Dodatek antioksidanta, kljub temu da preprečuje lipidno peroksidacijo v oleogelu, oslabi 3D mrežo oleogela in s tem vpliva na teksturne lastnosti. Ugotovili smo tudi, da trdna struktura oleogelov upočasni lipidno peroksidacijo v oleogelu in ohrani antioksidativni potencial rožmarinovega izvlečka. In this master's thesis oleogels were prepared from sunflower, olive, safflower, linseed and rapeseed oil. In order to find out how oil unsaturation degree affects the oleogels texture properties, fatty acid composition and iodine value of oils were determined. Texture properties measured included firmness and stickiness. Oleogels were made from fresh and highly oxidized oils as well as from oils with added rosemary extract. Beeswax was used as oleogelator at 1.5%, 2%, 3%, 5% and 7% (w/w). Oleogels were subjected to three different cooling processes and to different storage conditions in order to determine how oleogelator amount, the cooling and storage temperature affect the oleogels texture properties and oil binding capacity (OBC). We found out that the texture properties and OBC of oleogels are influenced by the beeswax content, the cooling and storage temperature, and oil type. The investigated oleogels are thermoreversible. The degree of lipid peroxidation in oils and oleogels was monitored by the peroxide value. The antioxidant potential of rosemary extract in oil and in oleogel was determined. The addition of the antioxidant, despite the fact that it prevents oxidation of oil in the oleogel, weakens the 3D structure of oleogel and so affects the texture properties. We also found out that the solid structure of oleogels slows down lipid peroxidation in the oleogel and preserves the antioxidant potential of rosemary extract.

V okviru diplomskega dela smo želeli ugotoviti, ali ima kaljenje semen navadnega rička (Camelina sativa L.) vpliv na antioksidativno učinkovitost (AU) pripravljenih izvlečkov. V analizo smo dobili metanolne izvlečke iz nekaljenih in kaljenih (24, 48, 72 in 96 ur) semen. AU smo določili kot sposobnost lovljenja 1,1-difenil-2-pikrilhidrazil radikala (DPPH·) in kot učinkovitost pri preprečevanju razbarvanja β-karotena v emulziji linolne kisline in vode. Rezultate pri prvi omenjeni metodi smo predstavili kot volumen izvlečka, ki je potreben za 50 % inhibicijo začetne vsebnosti DPPH· v reakcijski zmesi (EV50). Pri drugi metodi pa smo učinkovitost v emulziji (AUe) izrazili kot zmanjšanje razbarvanja β-karotena v emulziji, ki vsebuje izvleček, glede na obseg razbarvanja v emulziji brez izvlečka. Vsi preiskovani izvlečki fenolnih spojin iz nekaljenih in kaljenih semen so pri obeh metodah pokazali, da imajo antioksidativno učinkovitost. Pri metodi DPPH· je le izvleček iz semen, katerih kaljenje je trajalo 24 ur (EV50 = 24,8 ± 0,9 µL), pokazal večjo AU, kot jo je imel izvleček iz nekaljenih semen. V emulziji so imeli vsi izvlečki iz kaljenih semen slabšo učinkovitost od izvlečka iz nekaljenih semen (AUe = 83 ± 1 %). AUe izvlečka iz semen kaljenih 24 ur je bila blizu AUe izvlečka iz nekaljenih semen. In the frame of diploma work we aimed to determine whether the germination of seeds of Camelina sativa L. has an influence on the antioxidant effectiveness (AE) of prepared extracts. For analysis we obtained methanolic extracts from non-germinated and germinated (24, 48, 72 and 96 h) seeds. AE was determined as the ability to scavenge free 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) and as the effectiveness in preventing a discoloration of β-carotene in the emulsion of linoleic acid and water. The results of the first mentioned method were presented as the volume of the extract needed for the inhibition of 50 % of the initial DPPH· amount in the reaction mixture (EV50). In the second method, the effectiveness in emulsion (AEe) was expressed as a decrease in β-carotene discoloration in the emulsion containing an extract according to the extent of discoloration in emulsion without extract. All of the investigated extracts of phenolic compounds from non-germinated and germinated seeds showed to have an antioxidant effectiveness in both methods. At DPPH· method only the extract from seeds germinated for 24 h (EV50 = 24.8 ± 0.9 μL) showed higher AE than the extract from non-germinated seeds. In the emulsion all of the extracts from germinated seeds had lower effectiveness than extract from non-germinated seeds (AEe = 83 ± 1 %). The AEe of extract from seeds germinated for 24 h was close to AEe of extract from non-germinated seeds.

Cilj diplomskega dela je bila določitev vsebnosti skupnih fenolnih spojin v nekaljenem in kaljenem semenu navadnega rička (Camelina sativa L.). Zanimale so nas razlike v koncentraciji fenolnih spojin med nekaljenimi semeni in kaljenimi ter spremembe koncentracije fenolnih spojin tekom same kalitve (24 ur, 48 ur, 72 ur in 96 ur). Fenolne spojine varujejo živila pred oksidacijo, potekom roka uporabe in ščitijo človeka pred različnimi kroničnimi boleznimi. Živilo z visoko vsebnostjo fenolnih spojin tako predstavlja bolj zdrav način prehranjevanja. Suho snov v semenih smo določili s 5 urnim sušenjem vzorca na 105 °C in določanjem razlike v masi pred in po sušenju. Suha snov je z daljšim časom kaljenja začela padati, kar sovpada z vsrkavanjem vode v seme. Izvlečke navadnega rička smo pripravili z ekstrakcijo z metanolom ob stresanju, nato pa smo vsebnost fenolnih spojin določili s Folin-Ciocalteu metodo. Za lažje primerjanje vzorcev smo vsebnost skupnih fenolnih spojin podali kot ekvivalent klorogenske kisline v 1 g suhe snovi vzorca (mg KK/g DW). Vsebnost skupnih fenolnih spojin je bila dosti višja v kaljenih semenih kot v nekaljenih. Prav tako smo opazili rast vsebnosti skupnih fenolnih spojin tekom kalitve. Zaradi tega lahko kaljenje semen predstavlja naravno alternativo za izboljšanje hranilne vrednosti živila, namesto dodajanja sintetičnih aditivov in dodatkov. The aim of the graduation thesis was to determine the content of the total phenolic compounds in the non-germinated and germinated camelina seed (Camelina sativa L.). We were interested in differences in the concentration of phenolic compounds in non-germinated and germinated seeds and in changes of concentration of phenolic compounds during germination (24 hours, 48 hours, 72 hours and 96 hours). Phenolic compounds protect food from oxidation, prolong shelf life, and also protect people from various chronic diseases. A food with a high content of phenolic compounds thus represents a healthier way of eating. The dry matter in the seeds was determined by drying the sample at 105 °C for 5 hours and determining the difference in mass before and after drying. The dry matter began to decrease with a longer time of germination, which coincides with the absorption of water into the seed. The extracts of camelina were prepared by extraction in methanol by shaking. Subsequently, the content of phenolic compounds was determined by the Folin-Ciocalteu method. To facilitate sample comparison, the total content of phenolic compounds was given as the equivalent of chlorogenic acid per 1g of the dry sample (mg KK/g DW). The content of the total phenolic compounds was much higher in germinated seeds than in non-germinated ones. We also observed the growth of total phenolic compounds throughout germination. For this reason, seed germination may present a more natural way to improve the nutritional value of foods, instead of adding synthetic additives.

Tunina je vir več esencialnih hranil, vsebuje številne vitamine in minerale ter je bogata z nenasičenimi omega-3 maščobnimi kislinami zaradi česar velja za zdravo in kakovostno hrano. Vendar pa so raziskave pokazale, da vsebuje tunina tudi velike količine težkih kovin, kar potencialno ogroža človekovo zdravje. Arzen, kadmij, živo srebro in svinec so toksični elementi, ki se pogosto akumulirajo v mesu rib, kar lahko ob prevelikem vnosu vodi do zdravstvenih težav. Evropska komisija je v dokumentu No 1881/2006 tako določila maksimalne vrednosti, ki so dovoljene za težke kovine. Meja za vsebnost živega srebra je 1 mg/kg tunine, za svinec je 0,3 mg/kg tunine ter za kadmij 0,1 mg/kg tunine. V obravnavanih raziskavah za večino vzorcev niso zaznali prekoračenih maksimalnih dovoljenih količin v mesu rib. Tune, ki so vsebovale previsoke koncentracije težkih kovin, so bile ujete na industrijsko razvitem, onesnaženem in vulkansko aktivnem območju. V raziskavah so potrdili povezavo med velikostjo ribe in akumulacijo težkih kovin. Literaturni podatki kažejo, da je z velikostjo ribe koncentracija težkih kovin višja. Kljub temu, da je vsebnost toksičnih elementov, ki so jih določili v tunini, pod postavljeno mejo, priporočajo raziskovalci zmerno uživanje ribjega mesa, da ne pride do prekoračitve dopustnih tedenskih vnosov težkih kovin. Tuna fish is a source of more essential nutrients, contains vitamins and minerals, and is rich in unsaturated omega- 3 fatty acids. Therefore, fish are considered as healthy and good quality food. However, research shows that in addition to all benefits that consumption of tuna meat shows, tuna also contain large quantities of heavy metals that can potentially threaten human health. Arsenic, lead, cadmium and mercury are toxic elements, which are often accumulated in fish meat. The European Commission has therefore set maximum concentration limits for heavy metals in document: No 1881/2006. The limit for total mercury is 1 mg/kg of tuna, lead is 0.3 mg/kg of tuna and for cadmium is 0.1 mg/kg of tuna. According to studies, in most samples, maximal allowed quantities in fish meat were not exceeded. Samples, which contained excessive concentrations of heavy metals, were obtained from fish caught in a polluted and volcanic active area. Research has confirmed the correlation between the fish size and the accumulation of heavy metals. According to literature data, a higher concentration of heavy metals was detected in adult fish. Despite the fact that toxic elements in the tuna are detected below the limit, researchers recommend moderate consumption of fish meat in order to avoid excess of tolerable weekly intake.

V okviru magistrske naloge smo pripravili oleogel emulzije. Svežim oleogel emulzijam in oleogel emulzijam po 4 tednih shranjevanja smo določili trdoto, kohezivnost, konsistenco, jih umestili v barvni spekter CIE (L*,a*,b*) ter si s svetlobnim mikroskopom podrobneje ogledali njihovo strukturo. Oleogel emulzije smo pripravili iz sončničnega olja in vode v različnih razmerjih ter z dodatkom različnih kombinacij in vsebnosti čebeljega voska, zmesi mono- in digliceridov (Glicemul), kappa-karagenana (κ-karagenan) in kalijev klorid (KCl). Postopek, ki smo ga uporabili za pripravo oleogel emulzij, je zajemal tri stopnje: priprava oljne in vodne faze, združevanje obeh faz in homogenizacijo v ledeni kopeli. Ugotovili smo, da ima oleogelator (vosek, Glicemul) največji vpliv na teksturne lastnosti in barvo oleogel emulzij. Pri enaki koncentraciji oleogelatorja so oleogel emulzije z voskom manj trde, bolj lepljive, barva vzorcev pa je bolj izrazita v primerjavi z oleogel emulzijami z Glicemulom. 3 % čebeljega voska ali Glicemula v oljni fazi je najnižja koncentracija, ki omogoča nastanek čvrste oleogel emulzije. Z večanjem količine oleogelatorja se veča trdota, kohezivnost in konsistenca oleogel emulzij. κ karagenan v oleogel emulzijah z voskom deluje optimalno, kadar razmerje sestavin κ karagenan:vosek znaša 1:3 ali več. V oleogel emulzijah z Glicemulom je pri odmerjanju κ karagenana pomembno razmerje vode in Glicemula. Oleogel emulzija, ki vsebuje več voska in κ karagenana, je po shranjevanju mehkejša v primerjavi z oleogel emulzijami, ki ne vsebujejo hidrokoloida. Struktura oleogel emulzije z mono- in digliceridi je po 4 tednih shranjevanja stabilna oz. se lahko v določenih primerih še bolj učvrsti. Učinek KCl na teksturne lastnosti oleogel emulzij se razlikuje glede na razmerje med oljem in vodo ter glede na vsebnost voska. In this master’s thesis the oleogel-based emulsions were made of different combinations and ratios of sunflower oil, beewax, mixture of mono- and diglycerides (Glicemul), water, kappa-carrageenan (κ-carrageenan) and potassium chloride (KCl). Oleogel-based emulsions were analysed on firmness, cohezivness, consistency and CIE (L*,a*,b*) color values. Structure of oleogel emulsions were investigated on optical microscope. Oleogel-based emulsions were prepared in three stages: preparation of oil phase and water phase, combining them and homogenization in icy bath. We discovered that both oleogelators have the biggest effect on textural traits and color of oleogel-based emulsions. When the concentrations of oleogel-based emulsions were the same, those with wax were less hard, stickier and the color of samples was more distinct comparing to oleogel based emulsions with Glicemul. 3 % of beewax or Glicemul in oil phase is the lowest concentration, which enables creation of firm oleogel-based emulsion. When the quantity of oleogelator increases, so does the firmness, cohezivness and consistency of oleogel based emulsions. The κ-carrageenan in oleogel-based emulsions with wax works most optional when components ratios are 1:3 or more, in favor of wax. In oleogel-based emulsions with Glicemul, the proportion of water and Glicemul is important, when dosing κ carrageenan. Oleogel-based emulsion containing more wax and κ-carrageenan is softer after storage compared to oleogel based emulsions that do not contain hydrocolloids. The structure of mono and diglycerides in oleogel-based emulsions is after 4 weeks of storage stable or in some cases it can become even more firm. The effect of KCl on the texture traits of oleogel-based emulsions differs according to the ratio of oil and water to wax content.

Industrijska konoplja (Cannabis sativa L.) je vsestransko uporabna rastlina. Človeštvo jo goji že dolgo časa, saj je nekoč predstavljala pomemben vir vlaken, ki so se uporabljala za različne namene, od tkanja perila do izdelovanja jader. V današnjem obdobju je vse večji poudarek na prehranski vrednosti njenih semen, saj so bogat vir beljakovin in esencialnih maščobnih kislin. Vsebujejo tudi številna makro- in mikrohranila, poleg tega pa so prisotne tudi antioksidativne snovi, kamor uvrščamo tudi fenolne spojine. Olje semen industrijske konoplje je prepoznano kot funkcionalno živilo. Rezultati raziskav potrjujejo, da so med fenolnimi spojinami v semenih oziroma njihovem olju, prisotni predvsem flavonoidi. Ti vključujejo tudi posebno skupino tako imenovanih kanflavinov, ki so spojine značilne za industrijsko konopljo. Ugotovili so, da so poleg flavonoidov prisotni tudi nekateri predstavniki stilbenov in lignanov. Omenjene spojine niso samo dobri antioksidanti, temveč izkazujejo tudi druge pozitivne učinke. Industrial hemp (Cannabis sativa L.) is a widely used plant. It has been grown for a very long time, because it used to be an important source of fibres which were used for different purposes, from making clothes to sails. Nowadays its seeds are becoming more and more popular, mainly for their nutritional value, as they represent an important source of protein and essential fatty acids. They contain many beneficial macro- and micro-nutrients, alongside antioxidants, such as phenolic compounds. The oil of hemp seeds has been recognized as functional food. The results of different studies show that among phenolic compounds present in seeds or oil, flavonoids are the most abundant. They include a special group of so called cannflavins, which are unique to hemp. It has been found that beside flavonoids, some representatives of stilbenes and lignans are also present. All of these compounds aren't just good antioxidants, but have also shown some other beneficial effects.