1. Enhancing the properties and morphology of starch aerogels with nanocelluloseMilica Pantić, Mariusz Nowak, Gregor Lavrič, Željko Knez, Zoran Novak, Irena T. Žižović, 2024, izvirni znanstveni članek Ključne besede: starch aerogels, cellulose, supercritical impregnation, xanthohumol, usnic acid
Objavljeno v DKUM: 15.01.2025; Ogledov: 0; Prenosov: 1
 Celotno besedilo (11,15 MB) |
2. Optimization of the supercritical extraction and decarboxylation process of industrial hempTaja Žitek Makoter, Petra Kotnik, Teo Makoter, Željko Knez, Maša Knez Marevci, 2025, izvirni znanstveni članek Opis: Cannabinoids are the main active ingredients of Cannabis sativa L., obtained by a suitable extraction method and decarboxylation, in which the acid forms of the cannabinoids are converted into active forms. Supercritical CO2 extraction method and decarboxylation process were optimized for 7 cannabinoids (CBD, CBDA, THC, THCA, CBGA, CBN and CBC). The optimal extraction conditions for all cannabinoids were determined at a temperature of 60 °C and a pressure of 300 bar to 550 bar. At higher temperatures and reaction times, a significant depletion of neutral cannabinoids was observed. The optimal conditions of the decarboxylation process varied depending on the component. For the CBD component, which could be measured in the highest concentrations (560 mg/g), the optimal conditions were 140 °C and 10 min. The study can be an important model for predicting the behavior of cannabinoids under certain parameters.
Ključne besede: supercritical fluids, extraction, cannabinoids, decarboxilation, Cannabis sativa I
Objavljeno v DKUM: 08.01.2025; Ogledov: 0; Prenosov: 2
Celotno besedilo (10,15 MB) |
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4. Ellagitannin content in extracts of the chestnut wood aesculusTaja Žitek Makoter, Maša Knez Marevci, Željko Knez, 2024, izvirni znanstveni članek Ključne besede: antioxidant activity, chestnut wood, conventional extraction, extraction, fractionation, polyphenols, tannins, ultrasound extraction
Objavljeno v DKUM: 05.09.2024; Ogledov: 70; Prenosov: 10
Celotno besedilo (1,27 MB) |
5. Reinforcing ethyl cellulose aerogels with poly(lactic acid) for enhanced bone regenerationGabrijela Horvat, Jan Rožanc, Uroš Maver, Matjaž Finšgar, Željko Knez, Zoran Novak, 2024, izvirni znanstveni članek Opis: Developing double porous biodegradable and biocompatible scafolds that can incorporate and release drugs in a controlled manner holds immense potential in regenerative medicine. This study presents a synthesis method for preparing a macro-mesoporous scafold, where poly(lactic acid) adds to the macroporous region and mechanical properties, and ethyl cellulose adds to the surface area (182 m2 /g). High surface area enables the incorporation of model drug indomethacin with an entrapment efciency of 17.0% and its later controlled release profle. The resulting scafold has desirable mechanical properties in the range of a natural trabecular bone with a compressive modulus of 22.4 MPa. The material is stable in the simulated body fuids for 120 days before the slow degradation starts. In vitro studies demonstrate the material’s ability to support bone cell adhesion, proliferation, and diferentiation, promoting osteogenic activity. Overall, the unique combination of poly(lactic acid) and ethyl cellulose produces advanced materials with tailored macro and mesopore properties, remarkable mechanical properties, optimal degradation rate, and drug delivery potential, making it a promising candidate for bone scafolds in regenerative medicine and tissue engineering
Ključne besede: bio composite, polymer-matrix composites (PMCs), polymers, porosity/voids, secondary ion mass spectrometry
Objavljeno v DKUM: 23.08.2024; Ogledov: 130; Prenosov: 6
Celotno besedilo (2,87 MB) |
6. Antibacterial Komagataeibacter hansenii nanocellulose membranes with avocado seed bioactive compoundsKaja Kupnik, Mateja Primožič, Vanja Kokol, Željko Knez, Maja Leitgeb, 2024, izvirni znanstveni članek Ključne besede: bacterial nanocellulose membrane, avocado seed extracts, extraction, swelling, release, antibacterial activity
Objavljeno v DKUM: 23.08.2024; Ogledov: 70; Prenosov: 4
Celotno besedilo (1,80 MB) |
7. Multifunctional iron oxide nanoparticles as promising magnetic biomaterials in drug elivery : a ǂreviewKatja Vasić, Željko Knez, Maja Leitgeb, 2024, pregledni znanstveni članek Ključne besede: multifunctional biomaterials, bio-composites, nanocarriers, magnetic nanoparticles, modification, drug delivery
Objavljeno v DKUM: 20.08.2024; Ogledov: 72; Prenosov: 6
Celotno besedilo (5,66 MB) |
8. Mango peels as an industrial by-product: a sustainable source of compounds with antioxidant, enzymatic, and antimicrobial activityNika Kučuk, Mateja Primožič, Petra Kotnik, Željko Knez, Maja Leitgeb, 2024, izvirni znanstveni članek Opis: Plant waste materials are important sources of bioactive compounds with remarkable health-promoting benefits. In particular, industrial by-products such as mango peels are sustainable sources of bioactive substances, with antioxidant, enzymatic, and antimicrobial activity. Appropriate processing is essential to obtain highly bioactive compounds for further use in generating value-added products for the food industry. The objective of the study was to investigate and compare the biological activity of compounds from fresh and dried mango peels obtained by different conventional methods and unconventional extraction methods using supercritical fluids (SFE). The highest total phenolic content (25.0 mg GAE/g DW) and the total content of eight phenolic compounds (829.92 µg/g DW) determined by LC-MS/MS were detected in dried mango peel extract obtained by the Soxhlet process (SE). SFE gave the highest content of proanthocyanidins (0.4 mg PAC/g DW). The ethanolic ultrasonic process (UAE) provided the highest antioxidant activity of the product (82.4%) using DPPH radical scavenging activity and total protein content (2.95 mg protein/g DW). Overall, the dried mango peels were richer in bioactive compounds (caffeic acid, chlorogenic acid, gallic acid, catechin, and hesperidin/neohesperidin), indicating successful preservation during air drying. Furthermore, outstanding polyphenol oxidase, superoxide dismutase (SOD), and lipase activities were detected in mango peel extracts. This is the first study in which remarkable antibacterial activities against the growth of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) were evaluated by determining the microbial growth inhibition rate after 12 and 24 h incubation periods for mango peel extracts obtained by different methods. Ethanolic SE and UAE extracts from dried mango peels resulted in the lowest minimum inhibitory concentrations (MIC90) for all bacterial species tested. Mango peels are remarkable waste products that could contribute to the sustainable development of exceptional products with high-added value for various applications, especially as dietary supplements.
Ključne besede: mangifera indica, peels, bioactive substances, LC-MS/MS, proteins, enzymes, antibacterial activity
Objavljeno v DKUM: 12.08.2024; Ogledov: 104; Prenosov: 8
Celotno besedilo (6,49 MB) |
9. Alginate beads with encapsulated bioactive substances from mangifera indica peels as promising peroral delivery systemsNika Kučuk, Mateja Primožič, Željko Knez, Maja Leitgeb, 2024, izvirni znanstveni članek Opis: Since various bioactive substances are unstable and can degrade in the gastrointestinal tract, their stabilization is crucial. This study aimed to encapsulate mango peel extract (MPE) into edible alginate beads using the ionotropic gelation method for the potential oral delivery of bioactive substances. Mango peels, generally discarded and environmentally harmful, are rich in health-promoting bioactive substances. The alginate beads were examined for entrapment efficiency, particle size, morphology, thermal stability, physiochemical interactions, release profile under gastrointestinal conditions, and antibacterial efficacy. The study demonstrated the successful encapsulation of MPE with an efficiency of 63.1%. The in vitro release study showed the stability of the alginate beads in simulated gastric fluid with a maximum release of 45.0%, and sustained, almost complete release (99.4%) in simulated intestinal fluid, indicating successful absorption into the human body. In both fluids, the MPE release followed first-order kinetics. Encapsulation successfully maintained the antibacterial properties of MPE, with significant inhibitory activity against pathogenic intestinal bacteria. This is the first study on MPE encapsulation in alginate beads, presenting a promising oral delivery system for high-added-value applications in the food industry for dietary supplements, functional foods, or food additives. Their production is sustainable and economical, utilizing waste material and reducing environmental pollution.
Ključne besede: alginate beads, encapsulation, Mangifera indica, mango peels, characterization, in vitro release, antbacterial activity
Objavljeno v DKUM: 02.08.2024; Ogledov: 104; Prenosov: 18
Celotno besedilo (6,98 MB) |
10. Superkritični fluidi za izolacijo in formulacijo bioaktivnih snoviMaša Knez Marevci, Katja Andrina Kravanja, Željko Knez, 2024, pregledni znanstveni članek Ključne besede: podkritične tekočine, nadkritične tekočine, ekstrakcija, mikronizacija, impregnacija, nanašanje, sterilizacija
Objavljeno v DKUM: 30.07.2024; Ogledov: 141; Prenosov: 29
Celotno besedilo (401,35 KB)
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