Lignin is a unique and complex, a natural amorphous polymer. The exact chemical structure is not known well. Lignin is extremly versatile product which is found in all vascular plants, mostly between the cells, but also within the cells and in the cells walls. It provides plants a solid structure, it makes vegetables firm and crunchy and it enables trees to grow taller. The purpose of this thesis was the development and introduction of methods for the determination of lignin in healthy and diseased plants tissue in hop plants with spectrophotometric method. In this thesis we analysed the different parts of the hop plants (roots, leaves, vines and cones) with multiple extractions and compare what is the difference content of lignin in the diseased (e.g. citrus bark cracking viroid – CBCVd) and healthy hops. We presumed that the healthy plant has a higher content of lignin as the diseased plant, but we did not completely confirm that with the measurements. We found that in some parts of the plants are not significant differences in the content of lignin, while elsewhere they were. We have proved that the minimum content of lignin contain roots, followed by cones, leaves and vines. In this thesis we checked whether the wavelength used for measuring the absorbance in the literature appropriate. We have confirmed that the wavelength of 280 nm is suitable for work. We also confirmed that the method for determining the lignin in plant parts of hops with UV-Vis spectrophotometric method is accurate, precision (repeatability and reproducibility) and suitable for further analysis determination of lignin. Linearity test showed that the method is in the operating range of 0,53 mg to 6,6 mg of linear.

zelenjavi omogoča, da je bolj hrustljava in čvrsta, drevesom pa višjo rast. Namen diplomskega dela je bil razvoj in vpeljava metode za določanje lignina v rastlinskem tkivu zdravih in obolelih hmeljnih rastlin s spektrofotometričnim postopkom. V diplomskem delu smo z večkratnimi ekstrakcijami analizirali različne dele hmelja (korenine, liste, trto in storžke) ter primerjali razliko vsebnosti lignina v obolelem (npr. z viroidom razpokanosti skorje agrumov - CBCVd) in zdravem hmelju. Predpostavljali smo, da ima zdrava rastlina višjo vsebnost lignina kot obolela, česar z meritvami nismo povsem potrdili. Ugotovili smo, da pri nekaterih delih rastlin ni signifikantnih razlik pri vsebnosti lignina, drugje pa so. Tako smo dokazali, da najmanjšo vsebnost lignina vsebujejo korenine, sledijo jim storžki, listi in trta. Prav tako smo v diplomskem delu preverili ali je valovna dolžina, ki se uporablja za merjenje absorbance v literaturi, primerna. Potrdili smo, da je za delo primerna valovna dolžina 280 nm. Potrdili smo tudi, da je metoda za določanje lignina v rastlinskih delih hmelja z UV-Vis spektrofotometričnim postopkom točna, natančna (ponovljiva in obnovljiva) ter primerna za nadaljnje analize določanja lignina. Test linearnosti je pokazal, da je metoda v delovnem območju od 0,53 mg do 6,6 mg linearna.

Lignin je edinstven in kompleksni naravni amorfni polimer katerega natančna kemična struktura ni dobro znana. Je izjemno vsestranski izdelek, ki se nahaja v rastlinah, predvsem v celicah, med celicami in v celičnih stenah. Rastlinam zagotavlja trdno strukturo