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Namen diplomskega dela je bil preučiti, kako spreminjanje pogojev slajenja ječmena vpliva na kakovost kongresne sladice. Spreminjajoči dejavniki so bili temperatura (T) namakanja, odsotnost prezračevanja med namakanjem, čas in T kaljenja ter čas in T sušenja. V okviru diplomskega dela smo iz predhodno zaslajenega ječmena pripravili kongresne sladice, ki smo jih ovrednotili z določanjem ekstrakta, časa zasladitve, vrednosti pH, dinamične viskoznosti, vsebnosti prostega aminokislinskega dušika (FAN), vsebnosti skupnih fenolov in skupnih flavonoidov ter z določanjem sposobnosti lovljenja DPPH• radikala. Ugotovili smo očiten vpliv T namakanja, kaljenja in sušenja na kakovost kongresnih sladic. Stalna T namakanja in kaljenja je rezultirala v manjši akumulaciji (pri 10␃) ali izgubah (pri 20␃) ekstrakta in FAN v sladu, medtem ko so se kombinacije (nižja T namakanja + višja T kaljenja ali pa kombinacija nižje in višje T v času kaljenja) izkazale kot boljši režimi. Višje T sušenja so vodile do večjih izgub ekstrakta in FAN, a hkrati povečale vsebnost skupnih fenolnih spojin in flavonoidov ter antioksidativno učinkovitost. Krajši čas kaljenja je splošno vplival na slabše rezultate, za daljši čas kaljenja pa ne moremo z gotovostjo potrditi vpliva na izboljšanje rezultatov. The aim of diploma thesis was to investigate the impact of malting conditions on the Congress wort quality. The changing parameters were steeping temperature, lack of aeration during steeping, duration and temperature of germination and duration and temperature of kilning. Congress worts were prepared from pre-malted barley and were evaluated by determining the extract content, the time of starch convertion into sugars, the pH value, the dynamic viscosity, the free amino nitrogen (FAN) content, the total phenol and the total flavonoid content as well as the DPPH• radical scavenging ability. We found a significant effect of steeping, germination and kilning temperatures on the quality of Congress worts. A constant temperature of steeping and germination resulted in lesser accumulation (10␃) or greater losses (20␃) of extract and FAN content in malt, while their combinations (lower T of steeping + higher T of germination or a combination of lower and higher T in time of germination) were found to be better regimes. Higher kilning temperatures resulted in greater losses of extract and FAN, but at the same time increased the content of total phenolic compounds and flavonoids as well as antioxidant activity. A shorter germination time generally led to poorer results, meanwhile we could not directly confirm the positive effect of a longer germination time.

V doktorski disertaciji smo preučili vpliv različnih biotehnoloških procesov (kaljenja, fermentacije, encimske obdelave) na vsebnost in dostopnost ekstraktibilnih in vezanih fenolnih spojin v semenih pire in na njihovo in vitro ter in vivo antioksidativno aktivnost. Glavne identificirane fenolne spojine v pirinih semenih so bile ferulna, p-kumarna, kavna in p-hidroksibenzojska kislina. Pri iskanju optimalnih pogojev abiotskega stresa med kaljenjem semen za čim večji prirast fenolov, je kaljenje pri povečani slanosti in osmolarnosti brez aplicirane mehanske poškodbe najbolj povečalo vsebnost fenolnih spojin in izboljšalo njihovo antioksidativno aktivnost. Kombiniranje različnih biotehnoloških procesov predstavlja bistveno učinkovitejši način za povečanje vsebnosti fenolnih spojin kot posamezen proces. Največjo absolutno vsebnost ekstraktibilnih in vezanih posameznih fenolnih kislin smo določili v kaljenih semenih, fermentiranih s S. cerevisiae. Nadalje je obdelava kaljenih in fermentiranih semen s petimi hidrolitičnimi encimi znatno povečala vsebnost ekstraktibilnih fenolnih spojin, hkrati pa je imela negativen vpliv na vsebnost vezanih fenolnih spojin. Fenolne spojine iz kaljenih semen niso zaščitile modelnega organizma S. cerevisiae pred oksidacijo, medtem ko je večina ekstraktibilnih fenolnih spojin iz fermentiranih in encimsko obdelanih semen znižala znotrajcelično oksidacijo. Večji celični privzem fenolnih spojin ne pomeni nujno tudi večje antioksidativne aktivnosti in vivo, poleg količine je pomembna tudi oblika fenolnih spojin, ki vstopajo v celico. Rezultati kažejo na spremembe v sestavi ekstraktov med simulirano in vitro prebavo, saj so antioksidanti istega ekstrakta pokazali drugačen odziv proti različnim prostim radikalom v primerjavi z neobdelanimi semeni. Največjo vsebnost biološko dostopnih fenolnih spojin smo ugotovili v kaljenih semenih, fermentiranih s S. cerevisiae. Izgube fenolnih spojin po prebavi so bile velike, kljub temu pa so biološko obdelana semena imela še vedno znatno večjo vsebnost fenolnih spojin v primerjavi z neobdelanimi semeni. Within the scope of the doctoral dissertation, we investigated the influence of different biotechnological processes (germination, fermentation, enzymatic treatment) on the content and accessibility of extractable and bound phenolic compounds in spelt seeds, as well as on their antioxidant activity in vitro and in vivo. The major phenolic compounds identified in spelt seeds were ferulic, p-coumaric, caffeic and p-hydroxybenzoic acids. When searching for the optimal conditions of abiotic stress during seed germination to produce the greatest increase in phenolics, germination at increased salinity and osmolarity without applied mechanical damage showed the highest increase in phenolic compounds content and antioxidant activity. Combining different biotechnological processes represents the more effective way to increase the content of phenolic compounds than a single process. The highest absolute content of extractable and bound individual phenolic acids was found in germinated seeds fermented with S. cerevisiae. Moreover, treatment of germinated and fermented seeds with five hydrolytic enzymes significantly increased the content of extractable phenolic compounds, but at the same time had a negative effect on the content of bound phenolic compounds. Phenolic compounds of germinated seeds could not protect the model organism S. cerevisiae from oxidation, whereas most extractable phenolic compounds from fermented and enzymatic treated seeds reduced intracellular oxidation. Greater cellular uptake of phenolic compounds does not necessarily mean greater antioxidant activity in vivo, in addition to the quantity, the form of phenolic compounds entering the cell is also important. The results suggest changes in the composition of the extracts during simulated in vitro digestion, since antioxidants of the same extract showed a different response against various free radicals compared to the raw seeds. The highest content of bioaccessible phenolic compounds was found in germinated seeds fermented with S. cerevisiae. Losses of phenolic compounds after digestion were high, however, the bioprocessed seeds still contained higher content of phenolic compounds compared to raw seeds.

V sklopu magistrskega dela smo želeli preučiti vpliv kaljenja, namakanja, sušenja in kuhanja zrn na vsebnost nekaterih pomembnih komponent ajde, kvinoje in amaranta. V metanolnih ekstraktih smo določili vsebnost prostih fenolov in topnih konjugatov, za določanje vsebnosti vezanih fenolov pa je bila potrebna predhodna alkalna hidroliza rastlinskega matriksa. Posamezne frakcije fenolov smo ovrednotili s pomočjo Folin-Ciocalteujeve metode ter metode DPPH. Vsebnost fitinske kisline smo določili s pomočjo spektrofotometrične metode, za določanje vsebnosti topne in netopne prehranske vlaknine pa smo uporabili encimsko-gravimetrično metodo AOAC 991.43. Med preizkušenimi postopki bi pri vseh treh psevdožitih izpostavili 96 h kaljenje, ki je v zrnih znatno izboljšalo vsebnost in ekstraktibilnost celokupnih fenolov, njihov antioksidativni potencial ter najbolj pripomoglo k hidrolizi fitinske kisline. Kaljenje je precej povečalo vsebnost skupne prehranske vlaknine v ajdi in izboljšalo razmerje med topno in netopno frakcijo. Nadalje bi priporočali tudi 120 min sušenje zrn v pečici, zlasti v primeru prehranske vlaknine v amarantu in zmanjšane vsebnosti fitinske kisline v ajdi in kvinoji. Omenjen režim je precej doprinesel tudi k povečanju vsebnosti celokupnih fenolov in izboljšanju učinkovitosti antioksidantov v vseh treh vrstah psevdožit. Namakanje zrn v vodi se je izkazalo kot nekoliko manj primeren postopek, optimalni pogoji so bili odvisni od vrste psevdožita in preiskovanih parametrov. Kuhanje zrn je praviloma imelo negativen vpliv na večino analiziranih parametrov vseh treh psevdožit in ga zato odsvetujemo. The aim of the study was to analyse the respective impacts of germination, soaking, drying and cooking of grains on the nutritional components of buckwheat, quinoa and amaranth. Methanol extracts were utilised to determine the contents of free phenolic compounds and soluble conjugates, whilst alkaline hydrolysis of the sample plant matrix was necessary for the determination of bound phenolics content. Individual fractions of phenolics were evaluated using the Folin-Ciocalteu and DPPH assays, respectively. The content of phytic acid was determined with spectrophotometric method. The enzyme-gravimetric method AOAC 991.43 was used for the determination of soluble and insoluble dietary fibre contents. Amongst the preparation techniques of all three pseudocereals, the 96-hour germination is to be highlighted, as it substantially improved the content and extractability of total phenolics, their antioxidant potential and most contributed to the hydrolysis of phytic acid. Germination considerably increased the content of total dietary fibre in buckwheat grains and improved the ratio between the soluble and insoluble fractions. Furthermore, the study found that the process of drying the grains in the oven for 120 minutes is beneficial, which is particularly evident in the case of the dietary fibre of amaranth grains, and the decreased content of phytic acid in buckwheat and quinoa. The regimen also benefited in increasing contents of total phenolics and the efficacy of antioxidants in all three sorts of pseudocereals. Soaking of grains in water resulted as slighty less suitable technique as optimal conditions varied between the given pseudocereals and the analysed parameters. Cooking of grains had a negative impact on most of the investigated parameters and is therefore not recommended.

Namen diplomskega dela je s pregledom strokovne literature raziskati bioaktivne komponente iz žit, njihov vpliv na zdravje in možnosti za njihovo vključitev v funkcionalna živila. Funkcionalna živila so tista, ki v večji meri izkazujejo ugoden fiziološki učinek ali zmanjšano tveganje za kronične bolezni kot osnovna živila. V žitih najdemo veliko bioaktivnih komponent, ki pozitivno vplivajo na zdravje, senzorične in tehnološke lastnosti, kot so polifenolne spojine, vitamini, prehranska vlaknina in njene funkcionalne komponente – arabinoksilani, β-glukani, rezistentni škrob. Naštete bioaktivne komponente imajo antihiperzitivne, protimikrobne, prebiotične, probiotične, antioksidativne, protivnetne in imunomodulatorne lastnosti ter zmanjšujejo pojavnost bolezni srca in ožilja, sladkorne bolezni tipa 2, debelosti in raka. Naštete bioaktivne komponente ugodno vplivajo tudi na tehnološke lastnosti živil, saj služijo kot stabilizatorji, zgoščevalci, emulgatorji in nadomestki maščob. Ob vključitvi v funkcionalno živilo omogočajo izboljšavo hranilne vrednosti, kot je povišana vsebnost prehranske vlaknine ali zmanjšana vsebnost maščob, ter tehnoloških lastnosti, kot je izboljšan volumen izdelka in izboljšana tekstura, z minimalnim vplivom na senzorično vrednost. Neustrezen, tj. prevelik dodatek žitnih bioaktivnih komponent lahko vodi v preveč viskozen izdelek, ki ima majhen volumen, je trd, ima slabšo barvo in teksturo ali v živilu povzroči pojav nezaželenega okusa in arom. The aim of the thesis is to investigate the bioactive components of cereals, their impact on health and potential for their incorporation in functional foods by reviewing the literature. Functional foods are those that have beneficial physiological effect or reduced risk of chronic diseases compared to staple foods. Cereals contain many bioactive components that have a positive effect on health, sensory and technological properties, such as polyphenolic compounds, vitamins, dietary fiber and its functional components - arabinoxylans, β-glucan, and resistant starch. The listed bioactive components have antihypertensive, antimicrobial, prebiotic, probiotic, antioxidant, anti-inflammatory and immunomodulatory properties and reduce the incidence of cardiovascular diseases, type 2 diabetes, obesity and cancer. The listed bioactive components have a positive effect on the technological properties of foods, serving as stabilizers, thickeners, emulsifiers and fat substitutes. When included in a functional food, they enable the improvement of nutritional value, e.g., increased dietary fiber content or reduced fat content, and technological properties, e.g., improved product volume and texture, with minimal impact on its sensory value. Inappropriate, i.e., too large addition of cereal bioactive ingredients may result in a product with high viscosity, low volume, high strength, poor color and texture, and the appearance of undesirable taste and flavors.

V izvedbo magistrskega dela smo vključili 11 slovenskih sort hmelja in jih primerjali z znano nemško sorto Magnum. Iz hmeljnih briketov smo pri temperaturi 40 °C pripravili etanolne ekstrakte in jim določili vsebnost skupnih fenolnih spojin (SFS), skupnih flavonoidov (SF) in njihovih podskupin (flavonov in flavonolov (FF), flavanonov in dihidroflavonolov (FDH)) ter antioksidativni potencial (AOP). Zanimala nas je tudi korelacija med sorto hmelja in učinkovitostjo prehajanja SF, SFS, FF in FDH v pivo. V pivu smo določali še vsebnost alfa- in beta-kislin. Od slovenskih sort po vsebnosti SF, SFS in FF izstopa sorta Wolf. Več SF in SFS kot Magnum vsebujejo še sorte Fox, Aurora in Cardinal. Kolibri, Savinjski golding in Dragon so sorte z najmanjšo vsebnostjo SF in SFS. Najvišji AOP imajo sorte Dana, Gold in Aurora, medtem ko najnižji Savinjski golding. Daljši čas hladnega hmeljenja ugodno vpliva na večjo izluženost SF, SFS, FF in FDH v pivu, negativno pa na AOP piva. Največ SF so po sedmih dneh vsebovala piva hmeljena s sortami Wolf, Savinjski golding ali Bobek. Sorta Dana je po dodatku v pivo dala slabši rezultat kot Magnum. Po vsebnosti SFS in FF je izstopalo pivo s sorto Wolf. Največji prirast FDH smo potrdili pri pivu s sorto Aurora, najmanjši pri sorti Celeia. Pivu s sorto Dana smo določili enega najvišjih AOP. Najnižji AOP smo po sedmih dneh hmeljenja določili pivu z nemško sorto Magnum. Daljši čas hmeljenja je na večjo izluženost izo-alfa kislin vplival le pri štirih sortah: Wolf, Dragon, Aurora, Fox. Po enem dnevu hmeljenja smo največ kohumulona določili pivu s sorto Cardinal, največ n+adhumulona pivu s sorto Magnum, ksantohumola pa pivu s sorto Wolf vsi trije parametri so s časom hmeljenja pri omenjenih sortah postopoma upadli. In our master's thesis, we included 11 Slovenian hop varieties and compared them with the known German variety Magnum. Ethanol extracts were prepared from hop briquettes at 40°C and the content of total phenolic compounds (SFS), total flavonoids (SF) and their subclasses (flavones and flavonols (FF), flavanones and dihydroflavonols (FDH)) and antioxidant potential were determined (AOP). We were also interested in the correlation between hop variety and the efficiency of transfer of SF, SFS, FF and FDH into the beer. The content of alpha- and beta- acids was also determined in the beer. Among the Slovenian varieties, the Wolf variety stands out in terms of the content of SF, SFS and FF. Fox, Aurora and Cardinal also contain more SF and SFS than Magnum. Kolibri, Savinjski golding and Dragon are the varieties with the lowest content of SF and SFS. Dana, Gold and Aurora have the highest AOP, while Savinjski golding has the lowest. A longer period of dry hopping has a positive effect on the higher content of SF, SFS, FF and FDH in the beer and a negative effect on the AOP of the beer. After seven days of hopping, beers with the varieties Wolf, Savinjski golding and Bobek contained the most SF, meanwhile variety Dana resulted in lower values than Magnum. In terms of SFS and FF content, beer made with Wolf stood out. The highest increase in FDH content was found in beer with the Aurora variety, and the lowest with the Celeia variety. We determined one of the highest AOPs for beer with the Dana variety. After seven days of hopping, the lowest AOP was determined for beer with the German variety Magnum. Longer hopping time influenced the higher transfer of iso-alpha acids only in 4 varieties (Wolf, Dragon, Aurora, Fox). The highest cohumulone in beer was determined after one day of hopping for Cardinal, the most n + adhumulone for Magnum and xanthohumol for Wolf all three parameters gradually decreased with time of hopping.