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Namen magistrskega dela je bil preizkusiti delovanje protimikrobno učinkovitih fenolnih izvlečkov v kombinaciji s biopolimerom hitozanom za funkcionalizacijo aktivne embalaže živil. Delce izvlečkov smo kapsulirali v delce hitozana in jih naknadno dispergirali v makromolekularni raztopini hitozana ter formulacijo kot zunanjo plast dvoslojnega hitozanskega premaza nanesli na polimlečno-kislinske (PLA) folije z metodo valjčkanja. Fizikalni in kemijski nanos formulacij na površino folije smo spremljali z analizama ATR-FTIR in XPS, ki sta jasno pokazali prisotne funkcionalne skupine in kemijsko sestavo izvlečkov ter hitozana na površini. Omočljivost smo spremljali z analizo kontaktnega kota, ki se je pri vseh vzorcih zmanjšal in s tem pripomogel k zmanjšanju potencialne kondenzacije, kar je izjemnega pomena za praktično uporabo. Pri poskusu desorpcije z analizama ATR-FTIR in XPS smo zaznali migracijo elementov s površine folij, kar nakazuje na nestabilnost premazov. Rezultati analize SEM potrjujejo pokritost folij z različnimi nanosi, hkrati pa razkrivajo njihovo nehomogenost, kar bi lahko izboljšali s spremembo tehnologije nanosa. Novo razvite funkcionalizirane folije izkazujejo dobre antioksidativne lastnosti in več kot 95,0 % protimikrobno aktivnost proti patogeni bakteriji Staphylococcus aureus. Funkcionalizacija folij PLA s hitozanskimi premazi, obogatenimi z izbranimi izvlečki je bila uspešna ob sočasnem zagotavljanju hidrofilnih, antioksidativnih in protimikrobnih lastnosti. The aim of this work was to test the performance of antimicrobial-effective phenolic extracts in combination with biopolymer chitosan for the functionalization of active food packaging material. Particles of the extracts were encapsulated in chitosan biopolymer particles and dispersed in a macromolecular chitosan solution. Formulations were then applied as two-layer chitosan coatings of polylactic acid (PLA) films with the rolling method. The physical and chemical deposition of the formulations to the foil surface was monitored by ATR-FTIR and XPS analyses, which clearly showed the presence of functional groups and the chemical composition of the extracts and chitosan on the surface. The wettability was monitored with contact angle measurements, which decreased in all cases and thus contributed to the anti-fog foil properties, which are extremely important for practical use. In the desorption experiment with ATR-FTIR and XPS analysis, we detected the migration of elements from the surface of the foils, which indicates the instability of the coatings. The results of the SEM analysis confirm the coverage of the foils with different coatings, but simultaneously reveal the inhomogeneity of the coating, which could be improved by changing the coating technology. The newly developed functionalized films show good antioxidant properties and more than 95,0 % antimicrobial activity against the pathogenic bacteria Staphylococcus aureus. Functionalization of PLA films with biopolymer coatings with chitosan enriched with selected phenolic extracts was successful while providing hydrophilic, antioxidant, and antimicrobial properties. |
