Nemanja Krgović

Mr. Nemanja Krgović


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 October 2022 in Plants
Verified
Journal Article
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MJMiloš Jovanović
Miloš Jovanović
NKNemanja Krgović
Nemanja Krgović
Jelena ŽivkovićJelena Živković
Jelena Živković
TSTatjana Stević
Tatjana Stević
GZGordana Zdunić
Gordana Zdunić
Katarina ŠavikinKatarina Šavikin
Katarina Šavikin
Bilberry fruits (Vaccinium myrtillus L.) are one of the richest natural sources of anthocyanins and are widely used due to their pharmacological and nutritional properties. To ensure their maximum application potential, it is necessary to overcome the limitations of conventional extraction solvents and techniques. This study aimed to develop a green method for bilberry anthocyanin extraction using natural deep eutectic solvents (NaDES) integrated with ultrasound-assisted extraction (UAE) in order to define extraction conditions that will prevent decomposition of the anthocyanins or the loss of bioactivity. After a screening of ten different NaDES, choline chloride:sorbitol (1:1) was selected as the most effective. Furthermore, the influence analysis and optimization of the NaDES–UAE extraction conditions were carried out employing response surface methodology. The optimal conditions were found to be an extraction time of 37.63 min, a temperature of 48.38 °C, and 34.79% (w/w) water in NaDES. The extraction yields of target compounds under optimized extraction conditions were 0.27 mg/g DW of cyanidin-3-O-glucoside and 2.12 mg CGE/g DW of TAC. The obtained optimized extract showed promising radical scavenging and antimicrobial activity. A stability study with the optimized extract revealed that refrigerated storage at 4 °C in the dark provided the best anthocyanins preservation. Overall, the developed NaDES-UAE method showed promising application potential and can be considered as a high-efficiency green alternative to conventional anthocyanins extraction methods, enabling the preservation of active ingredients and the bioactivity of extracts.

20 November 2022 in Antioxidants
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MMMilica Martinović
Milica Martinović
NKNemanja Krgović
Nemanja Krgović
INIvana Nešić
Ivana Nešić
AZAna Zugic
Ana Zugic
VTVanja Milija Tadić
Vanja Milija Tadić
The aim of this study was to investigate the effect of the use of green solvents, natural deep eutectic solvents (NaDES), in comparison with conventional solvents on the extraction of free unbound phenolic compounds and the antioxidant activity of extracts of dried bilberry fruit, bilberry leaves and green tea leaves. After preparation of the extracts via ultrasound-assisted extraction using NaDES and conventional solvents (water and ethanol), spectrophotometric determination of total phenolic and flavonoid content, HPLC analysis of extracted polyphenols and antioxidant determination using FRAP, DPPH and ABTS assays were conducted. The results showed that NaDES have a great potential as agents for the extraction of phenolic compounds with potent antioxidant activity; the highest values of phenolic content and antioxidant activity were detected in the samples obtained by extraction using the NaDES combination betaine + urea. The bilberry leaves exhibited the highest flavonoid content among all extracts and turned out to be more active than bilberry fruits, to which they are often just a by-product during processing. The most active extract of all was the betaine-urea green tea leaves extract. Further research into the most active NaDES extracts should be performed.

18 January 2024 in Plants
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MRMilica Radan
Milica Radan
Nada Ćujić NikolićNada Ćujić Nikolić
Nada Ćujić Nikolić
SNSnežana Kuzmanović Nedeljković
Snežana Kuzmanović Nedeljković
ZMZorana Mutavski
Zorana Mutavski
NKNemanja Krgović
Nemanja Krgović
Katarina ŠavikinKatarina Šavikin
Katarina Šavikin
Recovering the bioactive components from pomegranate peel (PP) in the fruit-processing industry has attracted great attention in terms of minimizing the waste burden, as well as providing a new source of a multitude of functional compounds. The present study aimed to develop a feasible microencapsulation process of PP extract by using pectin and a pectin/2-hydroxypropyl-β-cyclodextrin (HP-β-CD) blend as coating materials. Microsized powders obtained by a spray drying technique were examined in terms of technological characteristics, exhibiting high powder yield and desirable moisture content, flowability, and cohesive properties. Assuming that the interactions with the used biopolymers occur on the surface hydrophobic domain, their presence significantly improved the thermal stability of the microencapsulated powders up to 200 °C. The health-promoting effects of PP have been associated with its high content in ellagitannins, particularly punicalagin. The obtained PP powders exhibited strong antioxidant and hypoglycemic potential, while an antimicrobial assay revealed their potent activity against Gram-positive bacteria. Additionally, an in vitro release study suggested that the used biopolymers can modify the release of target bioactive compounds, thus establishing a basis for developing an oral-controlled release system. Altogether, biowaste valorization from PP by the production of effective multifunctional microsized powders represents a sustainable way to obtain novel nutraceuticals and/or pharmaceuticals.

27 November 2023 in Plants
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SNSnežana Kuzmanović Nedeljković
Snežana Kuzmanović Nedeljković
MRMilica Radan
Milica Radan
Nada Ćujić NikolićNada Ćujić Nikolić
Nada Ćujić Nikolić
ZMZorana Mutavski
Zorana Mutavski
NKNemanja Krgović
Nemanja Krgović
Katarina ŠavikinKatarina Šavikin
Katarina Šavikin
The aim of the research was to develop microencapsulated powders of bilberry and chokeberry extracts via the spray drying technique. Two biopolymers, pectin alone and in combination with HP-β-CD, were used to preserve the antioxidant, hypoglycemic, photoprotective, and antimicrobial bioactivity of the berry leaf extracts. Moreover, the formed powders were characterized in terms of technological, chemical, and several biological properties. The obtained micro-sized powders (mean average particle diameter from 3.83 to 5.94 µm) demonstrated a process yield of up to 73%. The added biopolymers improved the flowability and cohesive properties of the powders and increased their thermal stability to 170 °C. The total content of polyphenolics in the powders ranged from 323.35 to 367.76 mg GAE/g DW for bilberry and from 186.85 to 227.59 mg GAE/g DW for chokeberry powders; meanwhile, chlorogenic acid was the predominant compound in powders. All samples showed stronger α-glucosidase inhibitory activity (IC50 values ranged from 5.00 to 19.59 µg/mL) compared with the reference standard. The study confirmed that spray drying is a suitable method for the preservation of the polyphenolic-rich extracts, while the addition of carriers has a positive effect on the improvement of microencapsulated powders’ properties.

11 October 2022 in Plants
Verified
Journal Article
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NKNemanja Krgović
Nemanja Krgović
MJMiloš Jovanović
Miloš Jovanović
Ana Z. Alimpić AradskiAna Z. Alimpić Aradski
Ana Z. Alimpić Aradski
TJTeodora Janković
Teodora Janković
TSTatjana Stević
Tatjana Stević
Katarina ŠavikinKatarina Šavikin
Katarina Šavikin
This study aimed to evaluate the potentials for skin-beneficial effects of the hydroethanolic extract of the aerial parts of ironwort (Sideritis raeseri Boiss. & Heldr. subsp. raeseri) and its fractions (petroleum ether, ethyl acetate, n-butanol and water). For these purposes, chemical analysis and in vitro antioxidant, anti-tyrosinase and antimicrobial assays, as well as determination of sun protection factor (SPF), were performed. The highest total phenolic content and quantity of individual flavonoids, chlorogenic acid and verbascoside were determined in the n-butanol fraction, which is in line with results obtained for antioxidant activity. The greatest antimicrobial activity against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa, the most common causative agents of the skin infections in humans, was exhibited by the ethyl acetate fraction. The strongest anti-tyrosinase activity was shown by the hydroethanolic extract (52.64% of inhibition at 100 μg/mL). Almost all tested samples showed photoprotective activity with SPF higher than 6 obtained at a low concentration of 0.1 mg/mL, which was more than 15 for the butanol fraction. These findings revealed that the hydroethanolic extract of S. raeseri aerial parts could be a valuable ingredient in the formulation of cosmetic and medicinal products intended to overcome various skin disorders.

9 August 2023 in Foods
Verified
Journal Article
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Marijana PonjavicMarijana Ponjavic
Marijana Ponjavic
VFVuk Filipovic
Vuk Filipovic
Evangelos TopakasEvangelos Topakas
Evangelos Topakas
Anthi KarnaouriAnthi Karnaouri
Anthi Karnaouri
Jelena ŽivkovićJelena Živković
Jelena Živković
Jasmina Nikodinovic-RunicJasmina Nikodinovic-Runic
Jasmina Nikodinovic-Runic
(1) Background: Bacterial nanocellulose (BNC) has gained in popularity over the years due to its outstanding properties such as renewability, biocompatibility, and bioavailability, and its use as an eco-friendly material of the future for replacing petrochemical products. (2) Methods: This research refers to the utilization of lignocellulose coming from wood waste via enzymatic hydrolysis to produce biopolymer BNC with an accumulation rate of 0.09 mg/mL/day. Besides its significant contribution to the sustainability, circularity, and valorization of biomass products, the obtained BNC was functionalized through the adsorption of black raspberry extract (BR) by simple soaking. (3) Results: BR contained 77.25 ± 0.23 mg GAE/g of total phenolics and 27.42 ± 0.32 mg CGE/g of total anthocyanins. The antioxidant and antimicrobial activity of BR was evaluated by DPPH (60.51 ± 0.18 µg/mL) and FRAP (1.66 ± 0.03 mmol Fe2+/g) and using a standard disc diffusion assay, respectively. The successful synthesis and interactions between BNC and BR were confirmed by FTIR analysis, while the morphology of the new nutrient-enriched material was investigated by SEM analysis. Moreover, the in vitro release kinetics of a main active compound (cyanidin-3-O-rutinoside) was tested in different release media. (4) Conclusions: The upcycling process of lignocellulose into enriched BNC has been demonstrated. All findings emphasize the potential of BNC–BR as a sustainable food industry material.