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The effect of supplements on which copper was sorbed on the pH value of humus : bachelor thesis
No full textU završnom radu ispitan je utjecaj različitih dodataka humusu na pH vrijednost humusa nakon uzgoja štitaste ognjice. Na temelju određenih pH vrijednosti može se zaključiti kako se aktualni aciditet humusa očekivano mijenja ovisno o dodatcima koji su u njega dodani. pH vrijednost aktualnog aciditeta humusa koji je zalijevan isključivo vodenom otopinom bakrovog(II) sulfata pentahidrata (pH = 4,72) znatno odstupa od pH vrijednosti ostalih uzoraka humusa te ga svrstava u grupu ultra jako kiselih tala. Ovakvo tlo ne bi trebalo biti pogodno za rast i razvoj štitaste ognjice. No usprkos tome, štitasta ognjica nije pokazala vidljive znakove fitotoksičnosti u promatranom periodu uzgoja.In this bachelor thesis, the effect of various humus supplements on its pH value after having a thyroid gland was examined. Based on the obtained pH values, it can be concluded that the actual humus acidity changes, as it was expected, depending on the added supplements. The actual acidity pH value of humus, which was watered solely with an aqueous solution of copper(II) sulfate pentahydrate (pH = 4.72), is significantly different from the pH value of other humus samples what classifies it as ultra-acidic soils. Such soil should not be suitable for the growth and development of garden candytuft. Despite this, the garden candytuft did not show any visible signs of phytotoxicity during the observed growing period
Biological potential of blackberries : bachelor thesis
No full textCilj ovoga rada bilo je istražiti biološki potencijal kupine i njenih nusproizvoda. Bogat kemijski i nutritivnim sastav ovog bobičastog voća ukazuje na brojna pozitivna biološka svojstva i vrlo važnu ulogu u prehrambenoj industriji. Zbog osjetljivosti plodova i sklonosti kvarenju, kupine se prerađuju u različite proizvode, a tijekom proizvodnje zaostaju jako vrijedni nusproizvodi kao što su trop, lišće i korijen . Brojne znanstvene studije ukazuju na mogućnost primjene nusproizvoda kupine za obogaćivanje drugih proizvoda ili pak kao zamjena za sintetske antioksidanse. Pregledom dostupne literature i dosadašnjih istraživanja biološkog potencijala kupine i njenih nusproizvoda, možemo potvrditi opravdanost njihove primjene u prehrambenoj industriji.The aim of this study was to investigate the biological potential of blackberries and their by-products. The rich chemical and nutritional composition of this berry fruit indicates its numerous biological properties and a very important role in the food industry. Due to the sensitivity of the fruit and its perishability, blackberries are processed into various products and during production, valuable by-products such as trop, leaves and roots remain. Numerous scientific studies indicate the possibility of using blackberry by- products to enrich other products or as a substitute for synthetic antioxidants. By reviewing the available literature and previous research on the biological potential of blackberries and its by-products, we can confirm the justification of their possible application in the food industry
Genetically modified food : bchelor thesis
No full textRazvoj biotehnologije doveo je do stvaranja genetski modificiranih orgnizama i genetski modificirane hrane. GMO predstavlja sve organizme kojima je genetski materijal izmijenjen na način koji se ne odvija prirodnim putem, a GM hrana je hrana proizvedena od genetski modificiranih biljaka ili životinja. GM hrana se nalazi na tržištu još od 1994. nakon predstavljanja Flavr Savr rajčica koje su proizvedene kako bi sporije sazrijevale. Postoji širok znanstveni konsenzus da GM hrana koja se trenutno nalazi na tržištu, ne predstavlja veći zdravstveni rizik od konvencionalne hrane. Ipak se smatra kontroverznom. S ciljem zaštite okoliša i zdravlja ljudi, uspostavljen je sustav regulacije transgenih organizama i njihovih produkata u Europskoj Uniji koji vrijedi i na području Hrvatske. Uredbe koje se trebaju poštovati na području Hrvatske su: 2018/350/EZ i 2009/41/EZ. U sklopu završnog rada provedeno je istraživanje u studentskoj populaciji putem anonimne ankete u svrhu dobivanja uvida o stavu ispitanika, odnosno mlađe populacije, prema GM hrani, prihvaćanju GM hrane na našem tržištu i deklariranju.The development of biotechnology has led to the creation of genetically modified organisms and genetically modified food. GMOs represent all organisms whose genetic material been modified in a way that does not occur naturally, and GM food is food produced from genetically modified plants or animals. GM foods have been on the market since 1994 after the introduction of Flavr Savr tomatoes that were produce to ripen more slowly. There is a broad scientific consensus that GM foods currently on the market do not pose a greater health risk than conventional foods. However, it is consider controversial. With the aim of protecting the environment and human health, a system of regulation of transgenic organisms and their products been established in the European Union, which is also valid in Croatia. Regulations to be respected in Croatia are 2018/350 / EC and 2009/41 / EC. As part of the final work, a survey was conduct in the student population through an anonymous survey in order to gain insight into the attitude of respondents, i.e. the younger population, towards GM food, acceptance of GM food in our market and declaration
Boron doped diamond electrodes : bachelor thesis
No full textDijamant dopiran borom (BDD) osim svojih vrhunskih svojstava materijala, nudi elektrokemičaru nekoliko značajnih svojstava čineći ga intrigantnim materijalom za elektrokemijska istraživanja. To uključuje najširi raspon potencijala elektrodnih materijala; niske pozadinske i kapacitivne struje; smanjeno nakupljanje naslaga u usporedbi s drugim elektrodama, sposobnost izdržavanja ekstremnih potencijala, korozivnog i visokog temperaturnog i tlačnog okruženja. Međutim, BDD nije tipičan materijal za elektrodu, to je poluvodič dopiran borom kako bi postigao karakteristike polumetala. Dopiranje borom omogućuje dijamantu da postane p-tipom poluvodiča i koristi se za različita elektroanalitička ispitivanja štetnih tvari kao što su teški metali, herbicidi, pesticidi, farmaceutici, ali i za određivanje različitih proteina. Uskoro možemo očekivati i sve veću primjenu BDD elektrode kao elektrokemijskog senzora.Boron doped diamond (BDD), in addition to its superior material properties, offers several notable attributes to the electrochemist making it an intriguing material for electrochemical research. These include the widest solvent window of all electrode materials; low background and capacitive currents; reduced fouling compared to other electrodes and; the ability to withstand extreme potentials, corrosive and high temperature and pressure environments. However, BDD is not your typical electrode material, it is a semi-conductor doped degenerately with boron to present semi-metallic characteristics. Boron doping allows the diamond to become a p-type semiconductor and is used for various electroanalytical tests of harmful substances such as heavy metals, herbicides, pesticides, pharmaceuticals, but also for the determination of various proteins. We can soon expect the increasing use of the BDD electrode as an electrochemical sensor
Determination of heavy metal ion concentration by electrochemical methods : bachelor thesis
No full textU ovom radu je ispitana mogućnost uklanjanja Cu 2+ iona iz vodene otopine CuSO 4 ×5H 2 O elektrokemijskim putem tj. procesom elektrotaloženja na elektrodi od Pt. Svrha mjerenja je bila snimanjem potenciodinamičkih polarizacijskih krivulja (i-E ovisnosti) u otopinama poznatih koncentracija (c = 1.0, 2.5, 5.0, 7.5 i 10 mM) te očitavanjem graničnih difuzijskih struja (i d ) odrediti nepoznatu koncentraciju Cu 2+ iona u CuSO 4 ×5H 2 O otopini. i-E ovisnosti su snimane u području potencijala od potencijala otvorenog strujnog kruga do –3.0 V uz različite brzine promjene potencijala (1, 5, 10, 20 i 50 mV/s). Kod većih koncentracija Cu 2+ iona, na površini Pt elektrode se taloži deblji sloj crvenkasto-smeđe prevlake bakra. Nadalje, granična difuzijska struja, i d , raste linearno s porastom koncentracije Cu 2+ iona u otopini elektrolita. Konstruiran je dijagram i d = f(c) te su određene nepoznate koncentracije Cu 2+ iona u tri nasumično pripremljene CuSO 4 ×5H 2 O otopine. Ustanovljeno je da se elektrokemijskim putem uspješno mogu ukliniti Cu 2+ ioni iz vodenih otopina te odrediti njihova koncentracijaIn this paper, the possibility of removing heavy metal ions, specifically Cu 2+ ions from an aqueous solution of CuSO 4 ×5H 2 O by electrochemical means (i.e. electrodeposition on the Pt electrode), was investigated. The purpose of the measurement was to determine the unknown concentration of Cu 2+ ions in CuSO 4 ×5H 2 O solution by recording potentiodynamic polarization curves (i-E dependences) in solutions of known concentrations (c = 1.0, 2.5, 5.0, 7.5 and 10 mM) and reading the limiting diffusion currents (i d ). i-E dependences were recorded in the potential range from the open circuit potential to –3.0 V at different scan rates (1, 5, 10, 20 and 50 mV/s). At higher concentrations of Cu 2+ ions, a thicker layer of copper coating is deposited on the Pt electrode surface. Furthermore, the limiting diffusion current, i d , increases linearly with increasing concentration of Cu 2+ ions in the electrolyte solution. A diagram i d = f(c) was constructed and unknown concentrations of Cu 2+ ions in three CuSO 4 ×5H 2 O solutions were determined. Heavy metal ions can be successfully electrochemically removed from polluted waters and their concentration can be determined
Immortelle, Helichrysum italicum (Roth)G. Don and traditional medicine of Mediterranean : bachelor thesis
No full textSmilje (Helichrysum italicum (Roth) G. Don) je samonikla biljka iz porodice glavočika (Asteraceae) i roda Helichrysum. Tipična je za područje Mediterana. Najviše se uzgaja zbog eteričnog ulja koje ima značajnu komercijalnu upotrebu. Kemijski sastav eteričnog ulja smilja na raznim područjima Mediterana bitno se razlikuje. Najčešći spojevi su: α-pinen, limonen, γ- kurkumen dok je neril-acetat najtraženiji kemijski spoj na tržištu zbog velikog značaja u kozmetičkoj industriji. Najviše ga ima u eteričnom ulju iz područja Korzike- 33,7-38,9%, dok ga eteričnom ulju iz Hrvatske ima 5,75–20,79%. Brojna ljekovita svojstva raznih ekstrakta smilja korištena u tradicionalnoj medicini, poslužila su kao temelj za znanstvena istraživanja. Od farmakološkog djelovanja, najviše se ističu antioksidativno i protuupalno. Veliki potencijal pruža antimikrobno djelovanje, pogotovo za razvoj novih lijekova.Immortelle (Helichrysum italicum (Roth) G. Don) is a wild plant from the Asteraceae family and the genus Helichrysum. It is a typical plant of the Mediterranean area. Mostly, it is cultivated because of the commercial use of its essential oil. The chemical composition of the essential oil of immortelle differs significantly in different areas of the Mediterranean. The most common compounds are α-pinene, limonene, γ-curcumene, while neryl-acetate is the most treasured chemical compound on the market because of its great importance in the cosmetic industry. It is mostly found in essential oil from the Corsica region - 33.7-38.9%, while in Croatia there is 5.75–20.79% of neryl-acetate in essential oil. Numerous medicinal properties of various immortelle extracts that are used in traditional medicine have served as the basis for scientific research. The most prominent pharmacological actions are antioxidant and anti-inflammatory activities. The antimicrobial activity has great potential, especially for the development of new drugs
Glucosinolate profile of horseradish (Armoracia rusticana). Conventional vs. microwave assisted isolation of volatiles : bachelor thesis
No full textGlukozinolati su sekundarni metaboliti koji se sintetiziraju iz aminokiselina. Pronađeni su u 16 porodica reda Brassicales, od kojih je najznačajnija porodica Brassicaceae (kupusnjača) u koju se ubrajaju brojne biljke svakodnevno korištene u prehrani, kao što su kupus, brokula, cvjetača i druge. Po kemijskoj strukturi glukozinolati su β- tioglukozidni-N-hidroksisulfatis varijabilnim bočnim lancem. Glukozinolati su kemijski i biološki neaktivni spojevi, a njihovom razgradnjom nastaju hlapljivi sumporovi spojevi koji imaju niz ljekovitih djelovanja. Oni se razgrađuju enzimskim, termičkim i kemijskim putem. U ovom radu primijenjene su različite metode razgradnje uključujući hidrodestilaciju u modificiranoj aparaturi po Clevengeru (100 °C, 150 min), mikrovalnu destilaciju i ekstrakciju (500 W, 98 °C, 15 - 30 min) koji su primjer termičke razgradnje te autoliza, nakon koje je uslijedila ekstrakcija s diklormetanom, koja je primjer enzimske razgradnje. Cilj rada bio je izolirati i identificirati sumporove spojeve iz hrena (Armoracia rusticana P. Gaertn., B. Mey. et Scherb.). Korijen i lišće hrena sakupljeno je u samoniklom nasadu u Konavlima (u blizini Dubrovnika, Hrvatska) u ožujku 2019. godine. Za identifikaciju spojeva korištene su GC-MS i HPLC-DAD tehnika. Analizom hlapljivih spojeva identificiran je alil-izotiocijanat, kao glavni produkt razgradnje glukozinolata koji potječe od sinigrina, zajedno s feniletil-izotiocijanatom i benzenpropanonitrilom, koji potječu od glukozinolata glukonasturcina. U listu hrena prisutan je samo sinigrin, dok je u korijenu uz sinigrin prisutan i glukonasturcin. Kasnije je potvrđeno HPLC-DAD tehnikom preko desulfatiziranih (desulfoglukozinolata) produkata.Glucosinolates are secondary metabolites that are synthesized from amino acid. They were found in 16 families of Brassicales, among the most important Brassicaceae family, which includes well-known plants of everyday nutrition such as cabbage, broccoli, cauliflower and others. Chemically these are β-thioglucoside-N-hydroxysulfates with a variable side chain. Glucosinolates are chemically and bioloyically inactice compounds, and with their degradation occur volatile sulfur compound which have a number of medicinal effects. They can be broken down by enzymatic, thermal and chemical ways. In our study we used different methods of degradation which includes hydrodistillation in a modified apparatus by Clevenger (100 °C, 150 min), microwave assisted distillation and extraction (500 W, 98 °C, 15 - 30 min), which are an example of thermal degradation, and autolysis followed by extraction with dichloromethane which is an example of enzymatic degradation. The aim of this study was to isolate and identify sulfur compounds from the horseradish (Armoracia rusticana P. Gaertn., B. Mey. et Scherb.). The roots and the leaves of horseradish were collected from the wild-growing population in Konavle (near Dubrovnik, Croatia) in March 2019. GC-MS and HPLC-DAD techniques were used to identify compounds. Analysis of the volatile compounds hasidentified the presence of allyl isothiocyanate, as the main glucosinolate degradation product originating form sinigrin, along with phenylethyl isothiocyanate and benzenpropanonitrile, originating from glucosinolate gluconasturtiin. Only sinigrin was present in the leaf of horseradish, while at the root, along with sinigrin, the presence of gluconasturtiin was also confirmed. It was later confirmed with HPLC-DAD technique acros desulfated (desulfoglucosinolates) products
Chemical properties of sea water : bachelor thesis
No full textJadransko more spada u plitko, poluzatvoreno more koje je jako osjetljivo na razne promjene u morskom okolišu. Veliku ulogu u promjeni svojstava (onečišćenja) ovog akvatorija imaju ljudske aktivnosti koje kontinuirano dovode do onečišćenja morskog ekosustava, zatim klimatske promjene i sve izraženiji razvoj industrije na moru. Stanje kakvoće Jadranskog mora je važno pratiti zbog gospodarske uporabe mora, zaštite zdravlja ljudi te održavanja biološke raznolikosti. Tema ovog rada je prikaz i opis najčešće određivanih pokazatelja Jadranskog mora i konkretni prikaz analiza uzoraka mora prikupljenih na području Splita. Uz standardne pokazatelje kao što su temperatura i praćenje razina mora, rad se bavi prikazom i načinom određivanja kloriniteta, saliniteta, sadržaja otopljenog kisika te sadržajem kalcija i magnezija.The Adriatic Sea is a shallow, semi-enclosed sea that is very sensitive to various changes in the marine environment. Human activities that continuously lead to pollution of the marine ecosystem, climate change and the increasingly pronounced development of the marine industry play a major role in changing the properties (pollution) of this area. The quality of the Adriatic Sea is important to monitor for the economic use of the sea, the protection of human health and the maintenance of biological diversity. The topic of this thesis is the presentation and description of the most frequently determined indicators of the Adriatic Sea, and a concrete presentation of the sea samples analysis collected in the area of Split. In addition to the usual indicators such as temperature and monitoring of sea levels, the thesis deals with the presentation and methods of determining chlorinity, salinity, the amount of dissolved oxygen and the content of calcium and magnesium
Influence of harvest location on chemical composition and biological activity of sea fennel : diploma thesis
No full textMotar (Crithmum maritimum L.) je vjerojatno jedan od najpoznatijih halofita na području Mediterana. Ova biljka se od davnina koristi u prehrambene i ljekovite svrhe obzirom da je odlikuje prisutnost visokih koncentracija vitamina C, polifenola, karotenoida te ostalih bioaktivnih spojeva. Cilj ovog rada bio je istražiti razlike u kemijskom sastavu i biološkim svojstvima motra prikupljenog sa tri različite lokacije; na riječnom staništu, staništu na samom ušću te na morskom staništu. Korištenjem uređaja za mikrovalnu ekstrakciju pripravljeni su biljni ekstrakti (94°C, 500 W, 30 min) kojima je određen udio ukupnih fenola, flavonoida te ukupnih tanina, dok je sadržaj klorogenske kiseline, koja je dominantan fenolni spoj u motru, određen primjenom visokodjelotvorne tekućinske kromatografije. Uzorcima je testirana i antioksidacijska aktivnost metodom određivanja redukcijske aktivnosti uzoraka (engl. Ferric Reducing Antioxidant Power, FRAP) te korištenjem dviju metoda određivanja sposobnosti hvatanja molekula slobodnog radikala pri čemu je korišten dušikov monoksid (NO • ) i 2,2-difenil-1-pikrilhidrazil radikal (DPPH). Na temelju dobivenih rezulata može se zaključiti da lokacija uzorkovanja biljke motar ima veliki utjecaj na kemijski sastav i antioksidacijska svojstva ekstrakata. Također, rezultati ukazuju na važnost individualnih fenolnih spojeva (klorogenske kiseline) na biološka svojstva ekstrakata.Sea fennel (Crithmum maritimum L.) is probably one of the most known halophytes in the Mediterranean region. This plant has been used from the earliest times for nutritional and medicinal purposes because it is characterized by a high concentration of vitamin C, polyphenols, carotenoids, and other bioactive compounds. The aim of this study was to explore the differences in chemical composition and biological properties of sea fennel collected from three different locations: river habitat, estuarine habitat, and marine habitat. Extracts of sea fennel were prepared by microwave-assisted extraction (94°C, 500 W, 30 min). Obtained extracts were tested for total phenolics, flavonoids, and tannins, while the content of chlorogenic acid, which is the dominant phenolic compound in sea fennel, was determined by using high-performance liquid chromatography. The antioxidant activity of the samples was also tested by Ferric Reducing Antioxidant Power (FRAP) assay, and using two free radical scavenging methods using nitric oxide (NO•), and 2,2-diphenyl-1-picrilhydrazil radical (DPPH). From the obtained results it could be concluded that the sea fennel harvest location has great effect on the chemical composition and antioxidant activity of the extracts. Furthermore, the results point out the importance of the individual phenolics (chlorogenic acid) on the overall activity of the sea fennel extracts
Antioxidant potential of blackberries : master thesis
No full textSlobodni radikali i druge reaktivne vrste mogu prouzročiti oksidaciju i biomolekularna oštećenja kada oksidacijske vrste dosegnu antioksidativnu obranu organizma, što rezultira oksidativnim stresom. To je povezano sa starenjem i razvojem patologija kao što su rak, kardiovaskularne bolesti, neurodegenerativni poremećaji, dijabetes i upale. Da bi se spriječio ili usporio oksidativni stres izazvan slobodnim radikalima, treba unositi dovoljne količine antioksidansa. Voće i povrće sadrži široku paletu antioksidativnih spojeva (fitokemikalija) koji mogu pomoći u zaštiti staničnih sustava od oksidacijskih oštećenja i smanjiti rizik od kroničnih bolesti. O antioksidativnim učincima bobičastog voća mogu se pronaći brojna istraživanja. Antioksidacijski učinak bobičastog voća u prvom se redu pripisuje fenolnim spojevima, uglavnom flavonioidima i antocijanima. U ovom radu ispitan je antioksidacijski potencijal soka te ekstrakata ploda kupine, lista kupine i nusproizvoda nastalog pri proizvodnji soka. Uz metodu određivanja ukupnog udjela fenola u testiranim uzorcima, korištene metode za određivanje antioksidacijskog djelovanja uključuju FRAP (eng. Ferric reducing antioxidant power), DPPH (eng. DPPH free radical scavenging) te ORAC (eng. Oxygen radical absorbance capacity) metodu. Dobiveni rezultati ukazuju na dobra antioksidacijska svojstva svih testiranih ekstrakata kupine gdje se posebno ističe ekstrakt lista kupine s najvećom antioksidacijskim potencijalom.Free radicals and other reactive species can cause oxidation and biomolecular damage when oxidative species exceed the body’s antioxidant defenses, resulting in oxidative stress. This is associated with aging and the development of diseases/conditions such as cancer, cardiovascular diseases, neurodegenerative disorders, diabetes and inflammation. To prevent or slow down oxidative stress caused by free radicals, sufficient amounts of antioxidants should be ingested. Fruits and vegetables contain a wide range of antioxidant compounds (phytochemicals) that can help protect cellular systems from oxidative damage and reduce the risk of chronic diseases. Numerous studies that describe the antioxidant effects of berries could be found. This effect is primarily attributed to phenolic compounds, mainly flavonoids and anthocyanins. In this paper, the antioxidant potential of blackberry juice and extracts, as well as extracts of blackberry leaves and juice by-products was investigated. Besides the total phenol content, samples were tested via FRAP (Ferric reducing antioxidant power), DPPH (DPPH free radical scavenging) and ORAC (Oxygen radical absorbance capacity) antioxidant assays. The obtained results indicate good antioxidant properties of all tested blackberry extracts, however the blackberry leaf extract stand out with the highest antioxidant potential