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IMPACT OF DRYING PROCESS ON MICROSTRUCTURE CHARACTERISTICS OF CULTIVATED BLUEBERRY (VACCINIUM CORYMBOSUM L.) : bachelor thesis
No full textKultivirana borovnica (Vaccinium corymbosum L.) je najvažnija komercijalna borovnica koja se konzumira u ljudskoj prehrani. Rod Vaccinium iz porodice Ericaceae obuhvaća velik broj vrsta koje za rast zahtijevaju dovoljnu količinu svjetlosti i kiselu sredinu pa se pronalaze u sredinama koje zadovoljavaju takvim uvjetima. Borovnice sadrže bogatstvo fitokemikalija koje pridonose zaštiti i očuvanju zdravlja ljudskog organizma. Različiti čimbenici (uzgoj, geografska regija, uvjeti skladištenja, zrelost, klima) utječu na njezin kemijski sastav i kvalitetu, a zbog visokog udjela vode i šećera, borovnica je bobičasto voće koje je vrlo lako podložno kvarenju. U ovom radu istražen je utjecaj različitih postupaka sušenja (konvekcijsko sušenje, vakuum sušenje, liofilizacija s različitim tehnikama smrzavanja) na mikrostrukturu plodova kultivirane borovnice. Nakon konvekcijskog i vakuumskog postupka sušenja, osušeni uzorci samljeveni su mlinom s noževima, a za liofilizirani uzorak ispitivana je razlika u mikrostrukturi plodova upotrebom mlina s noževima i kugličnog mlina. Za uspoređivanje razlika u mikrostrukturi svježih uzoraka i osušenih uzoraka primjenom konvekcijskog sušenja, vakuumskog sušenja te sušenja liofilizacijom, korištena je tehnika svjetlosne mikroskopije. Za sve uzorke korištena su ista povećanja (4 i 20 puta). Upotrebom pretražne elektronske mikroskopije istražena je i razlika u mikrostrukturi liofiliziranih plodova nakon različite predobrade uzoraka smrzavanjem (pri temperaturi od – 80 C i u struji tekućeg dušika na – 196 C) i nakon različitog načina mljevenja (mlin s noževima i kuglični mlin).Cultivated blueberry (Vaccinium corymbosum L.) is the most important commercial blueberry consumed in the human diet. The genus Vaccinium from the Ericaceae family includes a large number of species that require a sufficient amount of light and an acidic environment for growth, so they are found in environments that meet such conditions. Blueberries contain a wealth of phytochemicals that contribute to the protection and preservation of the health of the human body. Various factors (cultivation, geographical region, storage conditions, maturity, climate) affect its chemical composition and quality, and due to the high content of water and sugar, the blueberry is a berry that is very susceptible to spoilage. In this paper, the influence of different drying procedures (convection drying, vacuum drying, lyophilization with different freezing techniques) on the microstructure of cultivated blueberry fruits was investigated. After the convection and vacuum drying process, the dried samples were ground with a knife mill, and for the lyophilized sample, the difference in the microstructure of the fruits was examined using a knife mill and ball mill. To compare the differences in the microstructure of fresh samples and dried samples using convection drying, vacuum drying and lyophilization drying, the technique of light microscopy was used. The same magnifications (4 and 20 times) were used for all samples. Using scanning electron microscopy, the difference in the microstructure of lyophilized fruits was investigated after different pretreatment of samples by freezing (at a temperature of - 80 C and in a stream of liquid nitrogen at -196 C) and after different methods of grinding (knife and ball mill)
METABOLIC ANALYSIS OF URINE: DISCOVERING PREECLAMPSIA BIOMARKERS USING HS-SPME/GC-MS : diploma thesis
No full textPreeklampsija je bolest koja se javlja kod trudnih žena povezana s abnormalnom placentacijom koja se manifestira prvenstveno povišenim krvnim tlakom, a može se razviti ili tijekom trudnoće ili nakon nje. Može uzrokovati trajno oštećenje tkiva što dovodi do drastičnog opadanja kvalitete života i zdravlja djeteta ili majke, a u konačnici može dovesti i do njihove smrti. Nažalost, ova bolest još je nedovoljno istražena i ponekad se ne stigne primijetiti dovoljno rano da ne ostavi posljedice. Ideja ovog rada je obradom uzoraka urina zdravih trudnica i trudnica koje boluju od preeklampsije koristeći metodu HS-SPME/GC-MS, detektirati prisutne hlapljive organske spojeve. Korištenjem spektara masa i knjižnica spektara masa NIST, cilj je identificirati pojedini metabolit koji bi potencijalno mogao poslužiti kao biomarker za preeklampsiju.Preeclampsia is a disease that occurs in pregnant women and is associated with abnormal placental development. It primarily manifests as high blood pressure and can develop during or after pregnancy. It can cause permanent tissue damage, leading to a decline in the quality of life and health of the child or mother, and ultimately may even lead to their death. Unfortunately, this disease is still insufficiently understood and sometimes goes unnoticed until it is too late to prevent its consequences. The idea of this study is to analyze urine samples from healthy pregnant women and pregnant women with preeclampsia using the HS-SPME/GC-MS method to detect volatile organic compounds. By using mass spectra and NIST-mass libraries, the goal is to identify specific metabolites that could potentially serve as biomarkers for preeclampsia
PRODUCTION TECHNOLOGY OF WORT-BASED FUNCTIONAL BEVERAGE : diploma thesis
No full textFunkcionalni napitci su jedna od kategorija unutar koncepta funkcionalne hrane. Najpopularnija su i najraširenija kategorija funkcionalne hrane zahvaljujući svojoj praktičnosti, mogućnosti da zadovolje zahtjeve potrošača za poželjnim hranjivim tvarima i funkcionalnim sastojcima, jednostavnosti distribucije te mogućnosti mijenjanja veličine, oblika i izgleda ambalaže. Razvoj funkcionalnog napitka je složen proces, a funkcionalnost konačnog proizvoda ovisi o odabiru početnih sirovina i sastojaka, načinu (metodi) obrade, skladištenja, isporuke i postizanja odgovarajućih senzorskih svojstava. U ovom diplomskom radu proizveden je funkcionalni napitak na bazi sladovine dobivene od ječmenog slada koristeći Grainfather sustav. Tehnologija proizvodnje napitka može se podijeliti u dvije faze, a to su dobivanje sladovine (ukomljavanje) te fermentacija sladovine pomoću bakterija mliječne kiseline. Funkcionalnost proizvoda dijelom proizlazi iz same sirovine (ječma) koji sadrži fitokemikalije, a dijelom se postiže i tehnološkim (sladovanje) te biološkim postupkom (fermentacija). U proizvodnji su korištene bakterije mliječne kiseline koje svojim djelovanjem poboljšavaju organoleptička svojstva i produžuju rok trajanja napitka te imaju probiotičko djelovanje. Proizvedeni napitak karakterizira kiselkast okus zbog niske pH vrijednosti (3,65) koja je rezultat nastanka mliječne kiseline tijekom procesa fermentacije. Iako je GC-MS analizom utvrđeno da hlapljive spojeva arome u najvećem udjelu čine alkoholi poput etanola i 3-metilbutan-1-ola do izražaja najviše dolazi citrusni miris (po limunu) koji se pripisuje limonenu, spoju iz skupine terpena. Funkcionalnost napitka postignuta je izborom ječmenog slada kao sirovine te procesom fermentacije pomoću bakterija mliječne kiseline koje na taj način indirektno utječu na funkcionalnost proizvoda stvaranjem različitih poželjnih kao i smanjenjem nepoželjnih spojeva. Mikrobiološkom analizom je potvrđeno da bakterije mliječne kiseline u ovom napitku i direktno utječu na funkcionalnost kao probiotici zbog visokog broja bakterija (2,2×10 6 CFU/mL).Functional beverages are one of the categories within the concept of functional foods. They are the most popular and widely used category of functional foods because of their practicality, ability to meet consumer demand for desirable nutrients and functional components, ease of distribution and the ability to change size, shape and appearance of the packaging. The development of a functional beverage is a complex process, and the functionality of the final product depends on the selection of starting raw materials and ingredients, processing, storage, and delivery methods and the achievement of appropriate sensory characteristics. In this diploma thesis, a functional beverage based on barley malt wort was produced using the Grainfather system. The production technology of the beverage can be divided into two phases, namely the production of the wort (brewing) and the fermentation of the wort by lactic acid bacteria. The functionality of the product results on the one hand from the raw material itself (barley) due to its phytochemicals and on the other hand from the technological (malting) and biological (fermentation) processes. The lactic acid bacteria, used in the production process improve the organoleptic properties, extend the shelf life of the beverage and have a probiotic effect. The beverage produced is characterized by a sour taste due to the low pH value (3,65), resulting from the formation of lactic acid during the fermentation process. Although the GC-MS analysis showed that the volatile aroma substances are predominantly alcohols, such as ethanol and 3-methylbutan-1-ol, the citrus aroma (lemon-like), which is attributed to the compound from the terpene group limonene is most prominent. The functionality of the beverage is achieved through the selection of barley malt as raw material and the fermentation process using lactic acid bacteria, which indirectly affect the functionality of the product by forming various desirable compounds and reducing undesirable ones. The microbiological analysis confirmed that the lactic acid bacteria in this beverage also have direct impact on the functionality as probiotics due to the high number of bacteria (2,2×10 6 CFU/mL)
Chemical profile of essential oil from in vitro cultivated Ruta chalepensis L. : bachelor thesis
No full textRuta chalepensis L. je biljka karakteristična za područje Mediterana, ali je široko rasprostranjena i uzgajana širom svijeta, osobito u tropskim područjima. Eterično ulje R. chalepensis L. često se koristi u medicinske svrhe zbog svojih aromaterapijskih i farmaceutskih svojstava. Uz brojne prednosti, R. chalepensis posjeduje i neke toksične spojeve zbog čega je nužno pažljivo rukovanje i upotreba iste. Eterična ulja su smjese isparljivih spojeva s izraženim i karakterističnim mirisima. Dobivaju se iz raznih dijelova biljke, a ističu se svojim mirisima i ljekovitim svojstvima. Plinska kromatografija spregnuta sa spektrometrijom masa jedna je od najčešće korištenih tehnika za analizu isparljivih spojeva eteričnih ulja. Navedena tehnika omogućuje vrlo preciznu kvalitativnu i kvantitativnu analizu, čak kada je dostupna vrlo mala količina ispitivanog uzorka. U ovom radu opisane su izolacija i analiza eteričnog ulja R. chalepensis L. uzgojene na staničnoj liniji. Eterično ulje izolirano je iz biljnog materijala koristeći vodenu destilaciju te je provedena analiza tehnikom plinska kromatografija-spektrometrija masa. U sva tri eterična ulja najzastupljeniji spojevi su undekan-2-on, tridekan-2,4-dion, 2-undecil-acetat i dekanal. Također su pronađeni furanokumarini kalepensin, psoralen, metoksalen i bergapten.Ruta chalepensis L. is plant characteristic for the Mediterranean region but is widely distributed and cultivated worldwide, especially in tropical areas. The essential oil of R. chalepensis L. is often used for medicinal purposes due to its aromatherapy and pharmaceutical properties. Despite its numerous benefits, R. chalepensis contains some toxic compounds, necessitating careful handling and usage. Essential oils are mixtures of volatile compounds with distinct and characteristic scents. They are obtained from various parts of the plant and are known for their aromas and medicinal properties. Gas chromatography hyphenated with mass spectrometry is one of the most used techniques for analyzing volatile compounds in essential oils. This technique allows for very precise qualitative and quantitative analysis, even when only a small amount of the sample is available. This thesis describes the isolation and analysis of the essential oil of R. chalepensis L. grown on a cell line. The essential oil was isolated from plant material using water distillation, and analysis was carried out using gas chromatography-mass spectrometry. In all three essential oils, the most prevalent compounds are undecan-2-one, tridecan-2,4-dione, 2- undecyl acetate, and decanal. Furanocoumarins with toxic properties, including 3-(α,α-dimethylallyl)- psoralen (kalepensin), psoralen, methoxsalen, and bergapten, were also identified
THE PROCESSES OF PASSIVATION OF ALUMINIUM, TITANIUM AND STAINLESS STEEL : bachelor thesis
No full textU ovom radu opisuju se postupci pasivacije aluminija, titanija i njihovih legura te nehrđajućeg čelika. Pasivacijom površine stvara se oksidni film koji štiti metale od agresivne okoline. Pregledom literature prikazani su različiti načini postizanja pasivacije metala. Spontanom pasivacijom aluminija nastaje oksidni film koji pruža dobru zaštitu u atmosferskim uvjetima dok anodnom oksidacijom nastaje deblji oksidni film otporan u agresivnim sredinama. Na površini titanija i njegovih legura oksidni fim dobrih svojstava nastaje anodnom oksidacijom ili eloksiranjem. Postupak pasivacije nehrđajućih čelika opisan je prema normama ASTM A380 i ASTM A967. Pasivnost nehrđajućeg čelika povećava se prisutnošću kroma kao i nikla, molibdena, titanija ili niobija. Također, naznačena je važnost primjene pasivacije jer povećava zaštitu materijala od korozije, produljuje vijek trajanja proizvoda, uklanja nečistoće s površine metala te smanjuje potrebu za održavanjem.This paper describes the passivation processes for aluminum, titanium and its alloys, and stainless steel. Surface passivation involves the creation of an oxide film that protects the metals from an aggressive environment. A review of the literature shows that there are various ways of passivating metals. Spontaneous passivation of aluminum creates an oxide film that provides good protection under atmospheric conditions, while anodic oxidation creates a thicker oxide film that is resistant to aggressive environments. An oxide layer with good properties is produced on the surface of titanium and its alloys by anodic oxidation or anodization. The process of passivation of stainless steels is described in ASTM A380 and ASTM A967 standards. The passivity of stainless steel is increased by the presence of chromium as well as nickel, molybdenum, titanium or niobium. It also shows the importance of passivation, as it increases the corrosion protection of the materials, extends the life of the product, removes impurities from the metal surface and reduces the need for maintenance
IMPACT OF EXTRACTION SOLVENT ON THE PHENOLIC COMPOSITION AND ANTIOXIDANT PROPERTIES OF SEA FENNEL EXTRACTS : diploma thesis
No full textMotar (Crithmum maritimum L.) je halofit koji je odavno poznat u mediteranskoj kuhinji, no zadnjih godina istraživanja sve više ukazuju na njegov ekonomski potencijal i širu primjenu u prehrambene i medicinske svrhe. Biljku odlikuje bogat izvor bioloških aktivnih komponenti uključujući vitamin C, minerale, fenolne spojeve, klorogensku kiselinu te snažna antioksidacijska moć. U ovom istraživanju proučavan je utjecaj različitih ekstrakcijskih otapala na izolaciju fenolnih spojeva iz motra te antioksidacijska aktivnost ekstrakata, korištenjem DPPH (engl. 2,2-diphenyl-1-picryl-hidrazyl-hidrate) i FRAP (engl. Ferric Reducing Antioxidant Power) metoda. Vodenim i etanolnim ekstraktima dobivenih primjenom ultrazvučne ekstrakcije (60 C, 60 Hz, 30 min) ispitan je i utjecaj na inhibicijsku sposobnost oksidacije sezamovog ulja Rancimat metodom (120 C, 20 L/h). Rezultati su pokazali da odabir ekstrakcijskog otapala ima utjecaj na ekstrakciju ukupnih fenola, ukupnih flavonoida, ukupnih tanina te na antioksidacijska svojstva ekstrakata motra. Ekstrakt dobiven korištenjem 50%-tnog etanola ima najviši udio ukupnih fenola i ukupnih flavonoida, dok ekstrakt pripravljen s 96%-tnim etanolom sadrži najviši udio ukupnih tanina. Na temelju dobivenih rezultata može se zaključiti da alkoholni ekstrakti motra pokazuju bolju antioksidacijsku aktivnost od vodenog ekstrakta, te da se s povećanjem udjela alkohola produljuje vrijeme indukcije ulja. S druge strane, vodeni ekstrakt ima negativan učinak na stabilnost ulja, odnosno pro oksidacijsko djelovanje.Sea fennel (Crithmum maritimum L.) is a halophyte that has long been known in Mediterranean cuisine, but its economic potential and uses in food and medicine have recently become an increasing focus of research. The plant is characterized by a rich source of bioactive components, including vitamin C, minerals, phenolic compounds, chlorogenic acid, and potent antioxidant properties. In this study, the influence of different extraction solvents on the isolation of phenolic compounds from sea fennel and the antioxidant capacity of the extracts obtained were investigated using the DPPH (2,2-diphenyl-1-picryl- hydrazyl-hydrate) and FRAP (Ferric Reducing Antioxidant Power) methods. The impact on the oxidative stability of sesame oil was also studied using water and ethanol extracts obtained by ultrasound-assisted extraction (60 °C, 60 Hz, 30 min) by the Rancimat method (120 °C, 20 L/h). The results showed that the choice of extraction solvent had an effect on the extraction of total phenols, total flavonoids, total tannins, and antioxidant properties of sea fennel. The extract with 50% ethanol had the highest content of total phenols and total flavonoids, while the extract with 96% ethanol had the highest content of total tannins. The results indicate that alcohol extracts of sea fennel have better antioxidant activity than water extract, and increasing the alcohol content in the extract prolongs the induction time of sesame oil. The water extracts, on the other hand, had negative effects on oil stability and prooxidant activity
Thermal properties of PEO/Na Alg/LiBOB composites : diploma thesis
No full textModifikacija poli(etilen-oksida) (PEO) provedena je dodatkom različitih udjela soli litijevog bis(oksalata)borata (LiBOB) polimernoj mješavini PEO/NaAlg s ciljem poboljšanja vodljivosti pripravljenog krutog polimernog elektrolita (engl. Solid polymer electrolyte (SPE)) uslijed snižavanja udjela kristalne faze. Uspješno su pripravljeni samo neki filmovi kompozita metodom izlijevanja filma iz otopine. Primjenom infracrvene spektroskopije s Fourierovom transformacijom (FT-IR) utvrdilo se postojanje interakcija između eterske skupine PEO-a i kationa Li + iz LiBOB-a. Uočeni su pomaci određenih vibracijskih vrpci kao i promjene njihovih intenziteta. Pomoću diferencijalne pretražne kalorimetrije (DSC) provedeno je ispitivanje utjecaja različitih udjela litijevog bis(oksalata)borata na toplinska svojstva i kristalnost PEO-a. Dodatak litijeve soli LiBOB-a utječe na promjenu toplinskih svojstava PEO-a uz smanjenje stupnja kristalnosti PEO-a koje je najizraženije kod kompozita s najvećim udjelom soli. Primjenom neizotermne termogravimterije (TG) istraživan je utjecaj soli na toplinsku postojanost PEO/NaAlg-LiBOB kompozita. Toplinska razgradnja kompozita odvija se kroz maksimalno osam razgradnih stupnjeva. Sol narušava toplinsku postojanost početne mješavine pri čemu je utjecaj soli najizraženiji kod najvećeg udjela soli u kompozitu.The modification of properties of poly(ethylene oxide) (PEO) was performed by adding different content of salt lithium bis(oxalate)borate to polymer blend PEO/NaAlg with the aim of improving conductivity of solid polymer electrolyte (SPE) due to the lowering of its crystalline phase. Only some films of polymer blend PEO/NaAlg complexed with lithium bis(oxalate)borate have been successfully prepared by solution cast technique. Fourier transform infrared spectroscopy (FT-IR) confirmed the interaction between the ether group of PEO and the Li + cation from LiBOB. Shifts of certain vibration bands and changes in their intensities were observed. Differential scanning calorimetry (DSC) has been applied to investigate the influence of lithium bis(oxalate)borate on the thermal properties and crystallinity of PEO. The addition of salt has a effect on the thermal proporties of PEO while reducing its crystalinity, which is most pronounced in the composite with the highest salt content. By using non-isothermal thermogravimetry (TG), the effect of added salt on thermal stability of PEO/NaAlg/LiBOB composite was investigated. PEO/NaAlg-LiBOB composites degrades throught maximum eight degradation steps. The salt impairs the thermal stability of the initial polymer blend, with the influence of salt being most pronounced at the highest salt content in the composite
Establishing acceptance criteria for the surface preparation of ships steel structures for coatings protection : diploma thesis
No full textNajzastupljenija metoda zaštite brodskih čeličnih konstrukcija od korozije je primjenom premaza, a kvaliteta antikorozivne zaštite jedan je od osnovnih uvjeta za osiguranje dugotrajnosti konstrukcija. U ovom radu određeni su kriteriji prihvatljivosti određenih stupnjeva pripreme površine brodograđevnih limova tipa A za nanošenje sustava premaza. Na uzorke brodograđevnog čelika, koji su pripremljeni na različite stupnjeve čistoće, nanesen je sustav od tri premaza te su ispitana fizikalna, mehanička i antikorozivna svojstva sustava premaza prema važećim HR normama. Također, određene su emisije hlapivih organskih spojeva tijekom postupka antikorozivne zaštite.The most common method of corrosion protection of ship's steel structures is by coatings, and the quality of corrosion protection is one of the basic construction requirements for ensuring its’s longevity. In this paper, the criterion of acceptability of surface preparation degrees of ship-construction steel sheets (type A) before application of protective coating systems was established. A system of three coatings was applied on the surface of ship-construction steels samples which were prepared by different preparation methods and preparation grades. Afterwards physical, mechanical and anticorrosive properties of the protective coating system were tested according to the valid Croatian standards. Also, emissions of volatile organic compounds during the corrosion protection process were determined
Impact of PBT impeller speed on copper sorption on zeolite : bachelor thesis
No full textU radu je praćena i ispitana kinetika sorpcije bakra na NaX zeolitu te utrošak snage miješanja za ispitivani proces. Eksperimenti su provedeni u staklenom kotlastom reaktoru opremljenom s razbijalima virova. Miješanje je provedeno uz korištenje turbinskog miješala s ravnim lopaticama nagnutim pod kutom od 45° (PBT) pri četiri različite brzine vrtnje u izotermnim uvjetima. Kinetička analiza eksperimentalnih podataka Weber-Morrisovim i Blanchardovim kinetičkim modelima pokazala je da je ispitivana reakcija sorpcije bakra na površini NaX zeolita reakcija drugog reda i da se proces odvija u kinetičkom području.The kinetics of copper sorption on NaX zeolite and the mixing power consumption for the investigated process were monitored and investigated. The experiments were performed in a glass batch reactor equipped with baffles. Mixing was performed using a turbine impeller with flat blades inclined at an angle of 45° (PBT) at four different speeds in isothermal conditions. Kinetics analysis of experimental data by Weber-Morris and Blanchard kinetics models showed that the investigated copper sorption reaction on the surface of NaX zeolite is a second order reaction and that the process takes place in the kinetic region
Volatile compunds of brandy from plum, apple and pear : master thesis
No full textVoćne rakije spadaju u jaka alkoholna piće dobivena alkoholnom fermentacijom i destilacijom etilnog alkohola prirodnog podrijetla iz plodova voćki. Minimalni udio alkohola u voćnim rakijama je 37,5 % vol. Cilj ovog istraživanja bio je ustanoviti i usporediti profil hlapljivih spojeva tri različita uzorka voćne rakije. Hlapljivi spojevi izolirani su mikroekstrakcijom vršnih para na krutoj fazi (HS-SPME), koristeći svijetlo plavo i sivo vlakno i identificirani uz pomoć vezanog sustava plinska kromatografija- spektrometrija masa (GC-MS). Identificirano je ukupno 25 hlapljivih spojeva od kojih je 14 estera, 4 aldehida, 4 viša alkohola, 2 monoterpena, 1 seskviterpen. Najzastupljeniji hlapljivi spojevi su viši alkoholi 3-metilbutan-1-ol te etilni esteri etil-dekanoat i etil-oktanoat. Uočene su razlike u aromatskim profilima uzoraka ovisno o različitim recepturama i proizvodnim procesima.Fruit brandies belong to strong alcoholic beverages obtained by alcoholic fermentation and distillation of ethyl alcohol of natural origin from the fruits of fruit trees. The minimum alcohol content in fruit brandy is 37,5% vol. The aim of this research was to establish and compare the profile of volatile compounds of three different samples of fruit brandy. Volatile compounds were isolated by headspace solid phase microextraction (HS-SPME), using a light blue and gray fiber and were identified by a hyphenated system gas chromatography-mass spectrometry (GC-MS). A total of 25 volatile compounds were identified, of which 14 were esters, 4 aldehydes, 4 higher alcohols, 2 monoterpenes, 1 sesquiterpene. The most common volatile compounds are higher alcohols 3-methylbutan-1-ol and ethyl esters ethyl decanoate and ethyl octanoate. Differences in the aromatic profiles of the samples were observed depending on different recipes and production processes