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Spirulina is rich in various antioxidants and nutraceuticals and it has proven to be effective in the treatment of various pathological conditions. This study explores the antioxidant effect of fermented and non-fermented Spirulina extracts on the proteome level using the yeast Saccharomyces cerevisiae as a model organism. Yeast cells were treated with fermented Spirulina water extract (SV), non-fermented Spirulina water extract (NFV), fermented Spirulina ethanol extract (SE), and non-fermented Spirulina ethanol extract (NFE). Cell lysates were prepared, and label-free quantitative proteome analysis was performed. In SV, when compared to NFV samples, the levels of most differentially expressed proteins were upregulated. Alternatively, SE compared to NFE samples showed a significant downregulation for the majority of the analyzed proteins involved in different cellular processes. Additionally, a higher downregulation of stress response related proteins was observed in SE compared to NFE samples, while their abundance in SV samples increased compared to NFV. This study provided a global view, on a proteome level, of how cells cope with exogenous antioxidants and remodel their cellular processes to maintain metabolic and redox balance. Furthermore, it combined for the first time the analysis of different extract effect, including the contribution of lactic acid fermentation to the cell activity.
Jasmina Masten Rutar; Berta Cillero-Pastor; Ronny Mohren; Nataša Poklar Ulrih; Nives Ogrinc; Polona Jamnik. Insight into the Antioxidant Effect of Fermented and Non-Fermented Spirulina Water and Ethanol Extracts at the Proteome Level Using a Yeast Cell Model. Antioxidants 2021, 10, 1366 .
AMA StyleJasmina Masten Rutar, Berta Cillero-Pastor, Ronny Mohren, Nataša Poklar Ulrih, Nives Ogrinc, Polona Jamnik. Insight into the Antioxidant Effect of Fermented and Non-Fermented Spirulina Water and Ethanol Extracts at the Proteome Level Using a Yeast Cell Model. Antioxidants. 2021; 10 (9):1366.
Chicago/Turabian StyleJasmina Masten Rutar; Berta Cillero-Pastor; Ronny Mohren; Nataša Poklar Ulrih; Nives Ogrinc; Polona Jamnik. 2021. "Insight into the Antioxidant Effect of Fermented and Non-Fermented Spirulina Water and Ethanol Extracts at the Proteome Level Using a Yeast Cell Model." Antioxidants 10, no. 9: 1366.
Cinnamic and coumaric acids belong to the large family of phenylpropanoids with C6-C3 skeleton. Main biosynthetic route involves deamination of phenylalanine into trans-cinnamic acid, followed by hydroxylation into coumaric acids. In plants, p-coumaric acid is a predominant isomer that is preferentially bound to cell wall polysaccharides by ester bond. Food processing in general results in the release of bound acids that can be absorbed in the gastrointestinal tract. The maximum plasma concentration of coumaric acid is reached in minutes after ingestion, and halftime in blood circulation is longer than that of more hydroxylated cinnamates. Pure compounds as also complex plant extracts with high cinnamic and coumaric acid content have beneficial effects in amelioration of diabetes, carcinogenesis, or uncontrolled inflammation. Additionally normal physiological functioning of lipid and bone metabolism and neuroprotective and eye-protective effects were confirmed. Most experimental results were obtained on model animals and human and animal cell cultures; there is nevertheless lack of human intervention studies with pure compounds. Low acute toxicity in mammals and pronounced toxic effect on certain pathogenic microorganism, together with antioxidant activity of the molecules, point to the potential application for food conservation. A large number of patents related to the production and application of cinnamic and coumaric acids in food and other sectors were issued in the recent years.
Nataša Poklar Ulrih; Iztok Prislan; Blaž Cigić. Coumaric and Cinnamic Acids in Food. Handbook of Dietary Phytochemicals 2021, 1105 -1143.
AMA StyleNataša Poklar Ulrih, Iztok Prislan, Blaž Cigić. Coumaric and Cinnamic Acids in Food. Handbook of Dietary Phytochemicals. 2021; ():1105-1143.
Chicago/Turabian StyleNataša Poklar Ulrih; Iztok Prislan; Blaž Cigić. 2021. "Coumaric and Cinnamic Acids in Food." Handbook of Dietary Phytochemicals , no. : 1105-1143.
Studying the interactions between lipid membranes and various bioactive molecules (e.g., polyphenols) is important for determining the effects they can have on the functionality of lipid bilayers. This knowledge allows us to use the chosen compounds as potential inhibitors of bacterial and cancer cells, for elimination of viruses, or simply for keeping our healthy cells in good condition. As studying those effect can be exceedingly difficult on living cells, model lipid membranes, such as liposomes, can be used instead. Liposomal bilayer systems represent the most basic platform for studying those interactions, as they are simple, quite easy to prepare and relatively stable. They are especially useful for investigating the effects of bioactive compounds on the structure and kinetics of simple lipid membranes. In this review, we have described the most basic methods available for preparation of liposomes, as well as the essential techniques for studying the effects of bioactive compounds on those liposomes. Additionally, we have provided details for an easy laboratory implementation of some of the described methods, which should prove useful especially to those relatively new on this research field.
Luka Šturm; Nataša Poklar Ulrih. Basic Methods for Preparation of Liposomes and Studying Their Interactions with Different Compounds, with the Emphasis on Polyphenols. International Journal of Molecular Sciences 2021, 22, 6547 .
AMA StyleLuka Šturm, Nataša Poklar Ulrih. Basic Methods for Preparation of Liposomes and Studying Their Interactions with Different Compounds, with the Emphasis on Polyphenols. International Journal of Molecular Sciences. 2021; 22 (12):6547.
Chicago/Turabian StyleLuka Šturm; Nataša Poklar Ulrih. 2021. "Basic Methods for Preparation of Liposomes and Studying Their Interactions with Different Compounds, with the Emphasis on Polyphenols." International Journal of Molecular Sciences 22, no. 12: 6547.
The COVID-19 pandemic caused a large and involuntary shift to work from home (WFH) or teleworking, and widespread adoption of web-based platforms. This study aims to uncover the attitude and perception of WFH and online education among students and employees of the University of Ljubljana. A web-based questionnaire survey was conducted in November 2020, and more than 1300 valid responses were received. The lack of daily commuting, improved eating habits, and more time available for a family were the main reported advantages of WFH. The main issues, highlighted by respondents, were higher stress levels, lower study/work efficiency, and poorer working environment at home. When comparing the online educational process with the traditional one, the absence of traditional laboratory work, inadequate social interactions, and limitations of online knowledge assessment were identified as drawbacks by both students and educators. A significant difference between students and educators was observed in their opinion on the efficiency of online lectures compared to traditional ones, with the former being significantly more favored by students than educators. Overall, the majority of the respondents from all groups wish for the pre-COVID-19 study/work mode to be established as soon as possible. This implies that the perceived drawbacks of online education outweigh its advantages.
Varineja Drašler; Jasna Bertoncelj; Mojca Korošec; Tanja Pajk Žontar; Nataša Poklar Ulrih; Blaž Cigić. Difference in the Attitude of Students and Employees of the University of Ljubljana towards Work from Home and Online Education: Lessons from COVID-19 Pandemic. Sustainability 2021, 13, 5118 .
AMA StyleVarineja Drašler, Jasna Bertoncelj, Mojca Korošec, Tanja Pajk Žontar, Nataša Poklar Ulrih, Blaž Cigić. Difference in the Attitude of Students and Employees of the University of Ljubljana towards Work from Home and Online Education: Lessons from COVID-19 Pandemic. Sustainability. 2021; 13 (9):5118.
Chicago/Turabian StyleVarineja Drašler; Jasna Bertoncelj; Mojca Korošec; Tanja Pajk Žontar; Nataša Poklar Ulrih; Blaž Cigić. 2021. "Difference in the Attitude of Students and Employees of the University of Ljubljana towards Work from Home and Online Education: Lessons from COVID-19 Pandemic." Sustainability 13, no. 9: 5118.
Onion production generates abundant waste with high contents of bioactive compounds. These might have several beneficial functional properties for fortification of foods. To understand the variety and potential for further use, we examined various parts of the plants (edible/inedible waste/outer skin of onion), as well as extraction in water/ethanol and by shaking/sonication. Quercetin content and antioxidant capacity were initially determined for extracts of edible and waste parts of red, yellow and white onions, and red shallots. Ethanol extracts of the waste fraction had the highest quercetin content and antioxidant capacity. Except white onion, which contained no quercetin, the dried waste ethanol extracts contained up to 15 mg quercetin g−1 and had an antioxidant capacity of nearly 40 mg Trolox equivalents g−1. Furthermore, the dried skin ethanol extract of yellow onion, which is commercially the most available fraction, contained 8 mg quercetin g−1, with antioxidant capacity of 25 mg Trolox equivalents g−1 and high antimicrobial activity. Dried yellow onion skin showed good stability for the quercetin content under various storage conditions (4, 25, 37, 40 °C; dark/light; dry/moist air/in water). Bacteria, bacterial spores, yeast and mould counts remained unchanged for dried onion skin over 5 days under storage conditions that can promote food spoilage, indicating exceptional microbial stability. Finally, two different applications are demonstrated for dried yellow onion skin: tablets for home use (tablets as more convenient form of storage and for simple dosing in cooking), and a stabilisation additive (prolonged shelf-life of olive oil). Both represent efficient and straightforward approaches through waste prevention and food fortification.
Ilja Gasan Osojnik Črnivec; Mihaela Skrt; Danijela Šeremet; Meta Sterniša; David Farčnik; Erna Štrumbelj; Aleš Poljanšek; Nika Cebin; Lea Pogačnik; Sonja Smole Možina; Miha Humar; Draženka Komes; Nataša Poklar Ulrih. Waste streams in onion production: Bioactive compounds, quercetin and use of antimicrobial and antioxidative properties. Waste Management 2021, 126, 476 -486.
AMA StyleIlja Gasan Osojnik Črnivec, Mihaela Skrt, Danijela Šeremet, Meta Sterniša, David Farčnik, Erna Štrumbelj, Aleš Poljanšek, Nika Cebin, Lea Pogačnik, Sonja Smole Možina, Miha Humar, Draženka Komes, Nataša Poklar Ulrih. Waste streams in onion production: Bioactive compounds, quercetin and use of antimicrobial and antioxidative properties. Waste Management. 2021; 126 ():476-486.
Chicago/Turabian StyleIlja Gasan Osojnik Črnivec; Mihaela Skrt; Danijela Šeremet; Meta Sterniša; David Farčnik; Erna Štrumbelj; Aleš Poljanšek; Nika Cebin; Lea Pogačnik; Sonja Smole Možina; Miha Humar; Draženka Komes; Nataša Poklar Ulrih. 2021. "Waste streams in onion production: Bioactive compounds, quercetin and use of antimicrobial and antioxidative properties." Waste Management 126, no. : 476-486.
Lutein is a challenging compound to incorporate into food, as it is poorly soluble and unstable in aqueous solutions. In this study, the aim was to prepare stable encapsulates of lutein and lutein esters using feasible and straightforward techniques. Fine suspensions based on polyoxyethylene sorbitan monooleate and medium-chain triglyceride oil micelle-like units with 3.45% lutein esters or 1.9% lutein equivalents provided high encapsulation efficiencies of 79% and 83%, respectively. Lutein encapsulated in fine suspensions showed superior stability, as 86% was retained within the formulation over 250 days at 25 °C in the dark. Under the same storage conditions, only 38% of lutein remained in corresponding formulations. Higher encapsulation efficiencies were achieved with lecithin emulsions, at up to 99.3% for formulations with lutein, and up to 91.4% with lutein esters. In lecithin emulsions that were stored for 250 days, 17% and 80% of lutein and lutein esters, respectively, were retained within the formulations.
Zala Gombač; Ilja Osojnik Črnivec; Mihaela Skrt; Katja Istenič; Andreja Knez Knafelj; Igor Pravst; Nataša Poklar Ulrih. Stabilisation of Lutein and Lutein Esters with Polyoxyethylene Sorbitan Monooleate, Medium-Chain Triglyceride Oil and Lecithin. Foods 2021, 10, 500 .
AMA StyleZala Gombač, Ilja Osojnik Črnivec, Mihaela Skrt, Katja Istenič, Andreja Knez Knafelj, Igor Pravst, Nataša Poklar Ulrih. Stabilisation of Lutein and Lutein Esters with Polyoxyethylene Sorbitan Monooleate, Medium-Chain Triglyceride Oil and Lecithin. Foods. 2021; 10 (3):500.
Chicago/Turabian StyleZala Gombač; Ilja Osojnik Črnivec; Mihaela Skrt; Katja Istenič; Andreja Knez Knafelj; Igor Pravst; Nataša Poklar Ulrih. 2021. "Stabilisation of Lutein and Lutein Esters with Polyoxyethylene Sorbitan Monooleate, Medium-Chain Triglyceride Oil and Lecithin." Foods 10, no. 3: 500.
Dietary supplements based on algae, known for their nutritional value and bioactive properties, are popular products among consumers today. While commercial algal products are regarded safe by numerous studies, information about the production and origin of such products is scarce. In addition, dietary supplements are not as strictly regulated as food and medicinal drugs. We characterized different algal products (kelps: Laminariales, Spirulina spp., Chlorella spp., and Aphanizomenon flos-aquae), obtained on Slovenian market, based on their elemental composition (X-ray fluorescence, inductively coupled plasma–mass spectrometry), antioxidative potential [DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, total phenolic content], and stable isotope values [carbon (C), nitrogen (N), and sulfur (S); elemental analyzer isotope ratio mass spectrometry (EA-IRMS) method]. Antioxidative potential is consistent among products of the same type, with A. flos-aquae samples having 4.4 times higher antioxidative potential compared to Chlorella spp. and 2.7 times higher compared to Spirulina spp. Levels of toxic trace elements (arsenic, cadmium, mercury, and lead) are below the maximum allowed values and as such do not pose risk to consumers' health. Samples of Spirulina spp. have relatively high δ15N (7.4 ‰ ± 4.4‰) values, which indicate use of organic nitrogen sources in certain samples. Likewise, different elemental composition and isotopic ratios of stable elements (C, N, and S) for the samples with Spirulina spp. or Chlorella spp. are the consequence of using different nutrient sources and algae-growing techniques. Statistical analysis (principal component analysis) has confirmed that all tested A. flos-aquae samples originate from the same source, supposedly Klamath Lake (Oregon, USA). Hawaiian Spirulina pacifica can also be differentiated from all the other samples because of its characteristically high metal content (iron, manganese, zinc, cobalt, nickel, vanadium). Chlorella spp. and Spirulina spp. require further analyses with larger number of samples, as differentiation is not possible based on results of this study.
Jan Kejžar; Marta Jagodic Hudobivnik; Marijan Nečemer; Nives Ogrinc; Jasmina Masten Rutar; Nataša Poklar Ulrih. Characterization of Algae Dietary Supplements Using Antioxidative Potential, Elemental Composition, and Stable Isotopes Approach. Frontiers in Nutrition 2021, 7, 1 .
AMA StyleJan Kejžar, Marta Jagodic Hudobivnik, Marijan Nečemer, Nives Ogrinc, Jasmina Masten Rutar, Nataša Poklar Ulrih. Characterization of Algae Dietary Supplements Using Antioxidative Potential, Elemental Composition, and Stable Isotopes Approach. Frontiers in Nutrition. 2021; 7 ():1.
Chicago/Turabian StyleJan Kejžar; Marta Jagodic Hudobivnik; Marijan Nečemer; Nives Ogrinc; Jasmina Masten Rutar; Nataša Poklar Ulrih. 2021. "Characterization of Algae Dietary Supplements Using Antioxidative Potential, Elemental Composition, and Stable Isotopes Approach." Frontiers in Nutrition 7, no. : 1.
A bigger mechanistic picture of electrophilic aromatic substitution (EAS) is summarized and important “missing” postulates in EAS are unified.
Nikola Stamenković; Nataša Poklar Ulrih; Janez Cerkovnik. An analysis of electrophilic aromatic substitution: a “complex approach”. Physical Chemistry Chemical Physics 2021, 23, 5051 -5068.
AMA StyleNikola Stamenković, Nataša Poklar Ulrih, Janez Cerkovnik. An analysis of electrophilic aromatic substitution: a “complex approach”. Physical Chemistry Chemical Physics. 2021; 23 (9):5051-5068.
Chicago/Turabian StyleNikola Stamenković; Nataša Poklar Ulrih; Janez Cerkovnik. 2021. "An analysis of electrophilic aromatic substitution: a “complex approach”." Physical Chemistry Chemical Physics 23, no. 9: 5051-5068.
BACKGROUND Grape skins anthocyanins were extracted by a combination of ethanolic‐ultrasonic assisted methods and further encapsulated by freeze‐drying in soy phosphatidylcholine vesicles with the addition of different polymers, such as pectin, acacia gum, and whey proteins isolate. The goal of this research was to microencapsulate anthocyanin compounds extracted from grape skins, to characterize the stability and behavior of the vesicles and further to use them to obtain a newly light formulated mayonnaise. RESULTS The particle size ranged from 900 nm in control to 250 nm in whey proteins loaded vesicles. The powders showed higher encapsulation efficiency for all variants, ranging from 81 to 96%. Vibrational spectroscopy revealed a better inclusion of anthocyanins in polysaccharides‐based coacervates, whereas in protein‐based coacervates a possible interaction of anthocyanins with the amine groups was observed. The vesicles were tested for in vitro release, and the results confirmed the gradual release of the anthocyanins in both stages of digestion, with a residual content of about 50% in the vesicles. The powders displayed high stability during storage in the dark at 4 °C. The panelist positively appreciated the newly light formulated mayonnaises enriched with 10% dried vesicles compared with the control sample, in particular samples with acacia gum. CONCLUSION The study revealed that polymer‐loaded vesicles obtained presented stability in simulated gastrointestinal fluids and have proved successful in obtaining a new light enriched mayonnaises.
Oana Emilia Constantin; Nicoleta Stănciuc; Yinzhuo Yan; Ioana Otilia Ghinea; Claudia Ungureanu; Adrian Cîrciumaru; Deliang Wang; Natasa Poklar Ulrih; Gabriela Râpeanu. Polymers and protein‐associated vesicles for the microencapsulation of anthocyanins from grape skins used for food applications. Journal of the Science of Food and Agriculture 2020, 101, 2676 -2686.
AMA StyleOana Emilia Constantin, Nicoleta Stănciuc, Yinzhuo Yan, Ioana Otilia Ghinea, Claudia Ungureanu, Adrian Cîrciumaru, Deliang Wang, Natasa Poklar Ulrih, Gabriela Râpeanu. Polymers and protein‐associated vesicles for the microencapsulation of anthocyanins from grape skins used for food applications. Journal of the Science of Food and Agriculture. 2020; 101 (7):2676-2686.
Chicago/Turabian StyleOana Emilia Constantin; Nicoleta Stănciuc; Yinzhuo Yan; Ioana Otilia Ghinea; Claudia Ungureanu; Adrian Cîrciumaru; Deliang Wang; Natasa Poklar Ulrih; Gabriela Râpeanu. 2020. "Polymers and protein‐associated vesicles for the microencapsulation of anthocyanins from grape skins used for food applications." Journal of the Science of Food and Agriculture 101, no. 7: 2676-2686.
Cordycepin is the major bioactive component extracted from Cordyceps militaris. In recent years, cordycepin has received increasing attention owing to its multiple pharmacological activities. This study reviews recent researches on the anti‐inflammatory effects and the related activities of cordycepin. The results from our review indicate that cordycepin exerts protective effects against inflammatory injury for many diseases including acute lung injury (ALI), asthma, rheumatoid arthritis, Parkinson's disease (PD), hepatitis, atherosclerosis, and atopic dermatitis. Cordycepin regulates the NF‐κB, RIP2/Caspase‐1, Akt/GSK‐3β/p70S6K, TGF‐β/Smads, and Nrf2/HO‐1 signaling pathways among others. Several studies focusing on cordycepin derivatives were reviewed and found to down metabolic velocity of cordycepin and increase its bioavailability. Moreover, cordycepin enhanced immunity, inhibited the proliferation of viral RNA, and suppressed cytokine storms, thereby suggesting its potential to treat COVID‐19 and other viral infections. From the collected and reviewed information, this article provides the theoretical basis for the clinical applications of cordycepin and discusses the path for future studies focusing on expanding the medicinal use of cordycepin. Taken together, cordycepin and its analogs show great potential as the next new class of anti‐inflammatory agents.
Lu Tan; Xiaominting Song; Yali Ren; Miao Wang; Chuanjie Guo; Dale Guo; Yucheng Gu; Yuzhi Li; Zhixing Cao; Yun Deng. Anti‐inflammatory effects of cordycepin: A review. Phytotherapy Research 2020, 35, 1284 -1297.
AMA StyleLu Tan, Xiaominting Song, Yali Ren, Miao Wang, Chuanjie Guo, Dale Guo, Yucheng Gu, Yuzhi Li, Zhixing Cao, Yun Deng. Anti‐inflammatory effects of cordycepin: A review. Phytotherapy Research. 2020; 35 (3):1284-1297.
Chicago/Turabian StyleLu Tan; Xiaominting Song; Yali Ren; Miao Wang; Chuanjie Guo; Dale Guo; Yucheng Gu; Yuzhi Li; Zhixing Cao; Yun Deng. 2020. "Anti‐inflammatory effects of cordycepin: A review." Phytotherapy Research 35, no. 3: 1284-1297.
The influence of actively/passively encapsulated oleuropein on DPPC liposomes thermal and structural properties, and its antioxidant capacity against lipid peroxidation were investigated. Also, an oleuropein-rich olive leaf extract was encapsulated in soy phosphatidylcholine (PL-90 g) and incorporated in model and commercial drinks. Oleuropein induced a concentration-dependent broadening and splitting of the gel-to-liquid phase transition temperature. Fluorescence measurements revealed a fluidizing effect on liposomes below their gel-to-liquid phase transition temperature, and a higher lipid ordering above, especially to active encapsulation. Oleuropein also showed an antioxidant effect against lipid peroxidation in PL-90 g liposomes. PL-90 g Liposomes with olive leaf extract showed a mean diameter of 405 ± 4 nm and oleuropein encapsulation efficiency of 34% and delayed oleuropein degradation at pH 2.0 and 2.8 model drinks. In conclusion, greater effects were observed on the structure and fluidity of DPPC liposomes when oleuropein was actively encapsulated, while its incorporation into acidic foods in encapsulated form could enhance its stability.
Rodrigo González-Ortega; Luka Šturm; Mihaela Skrt; Carla Daniela Di Mattia; Paola Pittia; Nataša Poklar Ulrih. Liposomal Encapsulation of Oleuropein and an Olive Leaf Extract: Molecular Interactions, Antioxidant Effects and Applications in Model Food Systems. Food Biophysics 2020, 16, 84 -97.
AMA StyleRodrigo González-Ortega, Luka Šturm, Mihaela Skrt, Carla Daniela Di Mattia, Paola Pittia, Nataša Poklar Ulrih. Liposomal Encapsulation of Oleuropein and an Olive Leaf Extract: Molecular Interactions, Antioxidant Effects and Applications in Model Food Systems. Food Biophysics. 2020; 16 (1):84-97.
Chicago/Turabian StyleRodrigo González-Ortega; Luka Šturm; Mihaela Skrt; Carla Daniela Di Mattia; Paola Pittia; Nataša Poklar Ulrih. 2020. "Liposomal Encapsulation of Oleuropein and an Olive Leaf Extract: Molecular Interactions, Antioxidant Effects and Applications in Model Food Systems." Food Biophysics 16, no. 1: 84-97.
Propolis is a complex mixture of different biologically active compounds. Among these, phenols (especially flavonoids) and terpenes are the most important and abundant. As these compounds are gaining attention in development of suppressors of cancer and microbial disease, studies of their interactions with lipid membranes are becoming more and more relevant. In this article, the interactions of most of the important compounds from propolis (phenols: mostly flavonoids, and terpenes) with different kinds of model membranes are reviewed. Knowledge from these studies can be used for further development of new cancer suppressors and anti-microbial drugs, as well as for many more uses.
Luka Šturm; Nataša Poklar Ulrih. Propolis flavonoids and terpenes, and their interactions with model lipid membranes: a review. Advances in Biomembranes and Lipid Self-Assembly 2020, 25 -52.
AMA StyleLuka Šturm, Nataša Poklar Ulrih. Propolis flavonoids and terpenes, and their interactions with model lipid membranes: a review. Advances in Biomembranes and Lipid Self-Assembly. 2020; ():25-52.
Chicago/Turabian StyleLuka Šturm; Nataša Poklar Ulrih. 2020. "Propolis flavonoids and terpenes, and their interactions with model lipid membranes: a review." Advances in Biomembranes and Lipid Self-Assembly , no. : 25-52.
White mustard (Sinapis alba L.) seeds were investigated for their phenolic profile and antioxidant potential. Sinapic acid was identified in significant quantities, as sinapine, and also as methyl and ethyl sinapate, which are generally less reported in the literature. p-Hydroxybenzoic and sinapic acid were the main phenolic acids in both the free fraction and the fraction released from the soluble bound form, with higher p-hydroxybenzoic acid than sinapic acid. 4-Hydroxy-3-nitrophenylacetic acid and its alkyl esters were also identified. Among the flavonoids, the most abundant were quercetin and epicatechin. In addition to radical-scavenging activities, the mustard seed methanolic extract showed reducing power and chelating activity. On the basis of results of its effect in emulsion, bulk oil and oleogel oxidation assays and the polar nature of the principal antioxidant components, it would be best suitable in bulk oil and oleogel lipid systems, for the prevention of lipid peroxidation.
Neda Martinović; Tomaž Polak; Nataša Poklar Ulrih; Helena Abramovič. Mustard Seed: Phenolic Composition and Effects on Lipid Oxidation in Oil, Oil-in-Water Emulsion and Oleogel. Industrial Crops and Products 2020, 156, 112851 .
AMA StyleNeda Martinović, Tomaž Polak, Nataša Poklar Ulrih, Helena Abramovič. Mustard Seed: Phenolic Composition and Effects on Lipid Oxidation in Oil, Oil-in-Water Emulsion and Oleogel. Industrial Crops and Products. 2020; 156 ():112851.
Chicago/Turabian StyleNeda Martinović; Tomaž Polak; Nataša Poklar Ulrih; Helena Abramovič. 2020. "Mustard Seed: Phenolic Composition and Effects on Lipid Oxidation in Oil, Oil-in-Water Emulsion and Oleogel." Industrial Crops and Products 156, no. : 112851.
Two-layer functional coatings for polyethylene (PE) and polypropylene (PP) films were developed for the active packaging concept. Prior to coating, the polymer films were activated by O2 and NH3 plasma to increase their surface free energy and to improve the binding capacity and stability of the coatings. The first layer was prepared from a macromolecular chitosan solution, while the second (upper) layer contained chitosan particles with embedded catechin or pomegranate extract. Functionalized films were analyzed physico-chemically to elemental composition using ATR-FTIR spectroscopy and XPS. Further, oxygen permeability and wettability (Contact Angle) were examined. The antimicrobial properties were analyzed by the standard ISO 22196 method, while the antioxidative properties were determined with an ABTS assay. Functionalized films show excellent antioxidative and antimicrobial efficacy. A huge decrease in oxygen permeability was achieved in addition. Moreover, a desorption experiment was also performed, confirming that the migration profile of a compound from the surfaces was in accordance with the required overall migration limit. All these properties indicate the great potential of the developed active films/foils for end-uses in food packaging.
Sanja Potrč; Tjaša Kraševac Glaser; Alenka Vesel; Nataša Poklar Ulrih; Lidija Fras Zemljič. Two-Layer Functional Coatings of Chitosan Particles with Embedded Catechin and Pomegranate Extracts for Potential Active Packaging. Polymers 2020, 12, 1855 .
AMA StyleSanja Potrč, Tjaša Kraševac Glaser, Alenka Vesel, Nataša Poklar Ulrih, Lidija Fras Zemljič. Two-Layer Functional Coatings of Chitosan Particles with Embedded Catechin and Pomegranate Extracts for Potential Active Packaging. Polymers. 2020; 12 (9):1855.
Chicago/Turabian StyleSanja Potrč; Tjaša Kraševac Glaser; Alenka Vesel; Nataša Poklar Ulrih; Lidija Fras Zemljič. 2020. "Two-Layer Functional Coatings of Chitosan Particles with Embedded Catechin and Pomegranate Extracts for Potential Active Packaging." Polymers 12, no. 9: 1855.
Enzymes from thermophilic organisms are of particular importance for use in industrial applications, due to their exceptional stability and activity. Pernisine, from the hyperthermophilic archaeon Aeropyrum pernix , is a proteolytic enzyme that can degrade infective prion proteins and thus has a potential use for disinfection of prion-contaminated surfaces. Like other subtilisin-like proteases, pernisine needs to mature through an autocatalytic process to become an active protease. In the present study, we address the maturation of pernisine and show that the process is regulated specifically at high temperatures by the propeptide. Furthermore, we demonstrate the importance of a unique Ca 2+ -binding insertion for stabilization of mature pernisine. Our results provide a novel understanding of thermostable subtilisin autoactivation, which might advance the development of these enzymes for commercial use.
Miha Bahun; Marko Šnajder; Dušan Turk; Nataša Poklar Ulrih. Insights into the Maturation of Pernisine, a Subtilisin-Like Protease from the Hyperthermophilic Archaeon Aeropyrum pernix. Applied and Environmental Microbiology 2020, 86, 1 .
AMA StyleMiha Bahun, Marko Šnajder, Dušan Turk, Nataša Poklar Ulrih. Insights into the Maturation of Pernisine, a Subtilisin-Like Protease from the Hyperthermophilic Archaeon Aeropyrum pernix. Applied and Environmental Microbiology. 2020; 86 (17):1.
Chicago/Turabian StyleMiha Bahun; Marko Šnajder; Dušan Turk; Nataša Poklar Ulrih. 2020. "Insights into the Maturation of Pernisine, a Subtilisin-Like Protease from the Hyperthermophilic Archaeon Aeropyrum pernix." Applied and Environmental Microbiology 86, no. 17: 1.
Pernisine is a subtilisin-like serine proteinase secreted by the hyperthermophilic archaeon Aeropyrum pernix. The significant properties of this proteinase are remarkable stability and ability to degrade the infectious prion proteins. Here we show the production of pernisine in the periplasm of Escherichia coli. This strategy prevented the aggregation of pernisine in the cytoplasm and increased the purity of the isolated pernisine. The thermostability of this recombinant pernisine was significantly increased compared with previous studies. In addition, several truncated pernisine variants were constructed and expressed in E. coli to identify the minimally active domain. The catalytic domain of pernisine consists of the αẞα structurally similar core flanked by the N-terminal and C-terminal outer regions. The deletion of the C-terminal α helix did not affect the pernisine activity at 90 °C. However, the complete deletion of the C-terminal outer region resulted in loss of proteolytic activity. The pernisine variant, in which the N-terminal outer region was deleted, had a reduced activity at 90 °C. These results underline the importance of the Ca2+ binding sites predicted in these outer regions for stability and activity of pernisine. • Aggregation of produced pernisine was prevented by translocation into periplasm. • Thermostability of mature pernisine was increased. • The outer regions of the catalytic core are required for pernisine thermostability.
Miha Bahun; Kevin Hartman; Nataša Poklar Ulrih. Periplasmic production of pernisine in Escherichia coli and determinants for its high thermostability. Applied Microbiology and Biotechnology 2020, 104, 7867 -7878.
AMA StyleMiha Bahun, Kevin Hartman, Nataša Poklar Ulrih. Periplasmic production of pernisine in Escherichia coli and determinants for its high thermostability. Applied Microbiology and Biotechnology. 2020; 104 (18):7867-7878.
Chicago/Turabian StyleMiha Bahun; Kevin Hartman; Nataša Poklar Ulrih. 2020. "Periplasmic production of pernisine in Escherichia coli and determinants for its high thermostability." Applied Microbiology and Biotechnology 104, no. 18: 7867-7878.
The aim of this study was to characterize the properties of lactoferrin (LF) obtained in a process developed for its isolation from acid whey derived from the production of fresh curd cheese, using a unique technology of ion-exchange chromatography on CIM® monolithic columns. The freeze-dried lactoferrin samples produced on the pilot plant (capacity 1 m3) were examined for the purity, iron-binding capacity, antibacterial activity, and pH- and temperature-stability. Apo-LF inhibited several tested strains (enterobacteria, Staphylococcus, Streptococcus salivarius) except clostridia, lactic acid bacteria, and bifidobacteria. Sample of LF intentionally saturated with Fe3+ lost its antibacterial activity, indicating the involvement of mechanisms based on depriving bacteria of an iron source. All samples, regardless of the iron-saturation level, exhibited stability in pH range 4.0 to 11.0. LF with higher iron content (A-value = 41.9%) showed better thermal stability. Heat treatment up to 72 °C/3 s did not reduce antimicrobial activity against E. coli O157: H7 tox-. Higher purity (above 91%), higher iron-binding capacity and higher inhibitory activity against E. coli O157: H7 tox- compared to some similar products from the market was observed. These results demonstrate a high potential of monolithic ion-exchange chromatography for industrial processing of acid whey as a source of LF that can be used in new products with high-added value. The upscaling of the process is ongoing on a demonstration plant (10–30 m3/day capacity).
Bojana Bogovič Matijašić; Jernej Oberčkal; Petra Mohar Lorbeg; Diana Paveljšek; Nina Skale; Borut Kolenc; Špela Gruden; Nataša Poklar Ulrih; Marko Kete; Maja Zupančič Justin. Characterisation of Lactoferrin Isolated from Acid Whey Using Pilot-Scale Monolithic Ion-Exchange Chromatography. Processes 2020, 8, 804 .
AMA StyleBojana Bogovič Matijašić, Jernej Oberčkal, Petra Mohar Lorbeg, Diana Paveljšek, Nina Skale, Borut Kolenc, Špela Gruden, Nataša Poklar Ulrih, Marko Kete, Maja Zupančič Justin. Characterisation of Lactoferrin Isolated from Acid Whey Using Pilot-Scale Monolithic Ion-Exchange Chromatography. Processes. 2020; 8 (7):804.
Chicago/Turabian StyleBojana Bogovič Matijašić; Jernej Oberčkal; Petra Mohar Lorbeg; Diana Paveljšek; Nina Skale; Borut Kolenc; Špela Gruden; Nataša Poklar Ulrih; Marko Kete; Maja Zupančič Justin. 2020. "Characterisation of Lactoferrin Isolated from Acid Whey Using Pilot-Scale Monolithic Ion-Exchange Chromatography." Processes 8, no. 7: 804.
The dielectric properties of six refined edible oils with different fatty-acid compositions were determined for oils incubated at 180 °C up to 40 h. The oil degradation was evaluated by the dielectric dispersion and dielectric loss in the frequency range from 40 Hz to 2 MHz at 25 °C, refractive index, density, saponification number, and specific absorption coefficient at 232 and 268 nm. The dependence of the dielectric properties on frequency has been evaluated with Corach, Cole–Cole, and the universal power law models, giving the novel strategies for the interpretation of the dielectric spectra of thermally treated oils. The derived parameters—the dielectric constant, the electrical conductivity, the relaxation time τ and the exponents α, p, and n—are discussed with respect to the increased oxidation evidenced by specific absorption coefficients and polar products, as measured by the dielectric constant of the thermally treated oils. The specific refraction, specific polarization, orientation polarization, and dipole moment were determined using Lorenz–Lorentz, Debye and Onsager relationship. All above parameters obtained increased during the thermal treatment, except specific refraction, the electrical conductivity and the relaxation time. The dielectric constant-macroscopic parameter was compared with microscopic parameter polarization and dipole moment; the linear dependence was found to be .
Nataša Šegatin; Tanja Pajk Žontar; Nataša Poklar Ulrih. Dielectric Properties and Dipole Moment of Edible Oils Subjected to ‘Frying’ Thermal Treatment. Foods 2020, 9, 900 .
AMA StyleNataša Šegatin, Tanja Pajk Žontar, Nataša Poklar Ulrih. Dielectric Properties and Dipole Moment of Edible Oils Subjected to ‘Frying’ Thermal Treatment. Foods. 2020; 9 (7):900.
Chicago/Turabian StyleNataša Šegatin; Tanja Pajk Žontar; Nataša Poklar Ulrih. 2020. "Dielectric Properties and Dipole Moment of Edible Oils Subjected to ‘Frying’ Thermal Treatment." Foods 9, no. 7: 900.
Sprouts and microgreens are a rich source of various bioactive compounds. Seeds of lentil, fenugreek, alfalfa, and daikon radish seeds were germinated and the contents of the polyamines agmatine (AGM), putrescine (PUT), cadaverine (CAD), spermidine (SPD), and spermine (SPM) in ungerminated seeds, sprouts, and microgreens were determined. In general, sprouting led to the accumulation of the total polyamine content. The highest levels of AGM (5392 mg/kg) were found in alfalfa microgreens, PUT (1079 mg/kg) and CAD (3563 mg/kg) in fenugreek sprouts, SPD (579 mg/kg) in lentil microgreens, and SPM (922 mg/kg) in fenugreek microgreens. A large increase in CAD content was observed in all three legume sprouts. Conversely, the nutritionally beneficial polyamines AGM, SPD, and SPM were accumulated in microgreens, while their contents of CAD were significantly lower. In contrast, daikon radish sprouts exhibited a nutritionally better profile of polyamines than the microgreens. Freezing and thawing of legume sprouts resulted in significant degradation of CAD, PUT, and AGM by endogenous diamine oxidases. The enzymatic potential of fenugreek sprouts can be used to degrade exogenous PUT, CAD, and tyramine at pH values above 5.
Irena Kralj Cigić; Sašo Rupnik; Tjaša Rijavec; Nataša Poklar Ulrih; Blaž Cigić. Accumulation of Agmatine, Spermidine, and Spermine in Sprouts and Microgreens of Alfalfa, Fenugreek, Lentil, and Daikon Radish. Foods 2020, 9, 547 .
AMA StyleIrena Kralj Cigić, Sašo Rupnik, Tjaša Rijavec, Nataša Poklar Ulrih, Blaž Cigić. Accumulation of Agmatine, Spermidine, and Spermine in Sprouts and Microgreens of Alfalfa, Fenugreek, Lentil, and Daikon Radish. Foods. 2020; 9 (5):547.
Chicago/Turabian StyleIrena Kralj Cigić; Sašo Rupnik; Tjaša Rijavec; Nataša Poklar Ulrih; Blaž Cigić. 2020. "Accumulation of Agmatine, Spermidine, and Spermine in Sprouts and Microgreens of Alfalfa, Fenugreek, Lentil, and Daikon Radish." Foods 9, no. 5: 547.
Knotweed is a flowering plant that is native to temperate and subtropical regions in the northern hemisphere. We evaluated Japanese (Reynoutria japonica Houtt.) and Bohemian (Fallopia x bohemica) knotweed rhizome and flower ethanol extracts and compared them in terms of their biological activities. The specific polyphenols were identified and quantified using HPLC/DAD, and the antioxidant activity was determined using 2,2-diphenly-1-picrylhydrazyl (DPPH) and cellular antioxidant capacity assays. The anticancer activity was evaluated as the difference between the cytotoxicity to cancer cells compared with control cells. The antimicrobial activity was determined using bacteria and yeast. The antidiabetic activity was tested as the ability of the extracts to inhibit α-amylase. Both rhizome extracts were sources of polyphenols, particularly polydatin and (−)-epicatechin; however, the cellular assay showed the highest antioxidant capacity in the flower extract of F. bohemica. The PaTu cell line was the least sensitive toward all knotweed extracts. The flower extracts of both species were less toxic than the rhizomes. However, the activity of the tested extracts was not specific for cancer cells, indicating a rather toxic mode of action. Furthermore, all used extracts decreased the α-amylase activity, and the rhizome extracts were more effective than the flower extracts. None of the extracts inhibited bacterial growth; however, they inhibited yeast growth. The results confirmed that rhizomes of Reynoutria japonica Houtt. could become a new source of bioactive compounds, which could be used for the co-treatment of diabetes and as antifungal agents.
Lea Pogačnik; Tina Bergant; Mihaela Skrt; Nataša Poklar Ulrih; Jitka Viktorová; Tomáš Ruml. In Vitro Comparison of the Bioactivities of Japanese and Bohemian Knotweed Ethanol Extracts. Foods 2020, 9, 544 .
AMA StyleLea Pogačnik, Tina Bergant, Mihaela Skrt, Nataša Poklar Ulrih, Jitka Viktorová, Tomáš Ruml. In Vitro Comparison of the Bioactivities of Japanese and Bohemian Knotweed Ethanol Extracts. Foods. 2020; 9 (5):544.
Chicago/Turabian StyleLea Pogačnik; Tina Bergant; Mihaela Skrt; Nataša Poklar Ulrih; Jitka Viktorová; Tomáš Ruml. 2020. "In Vitro Comparison of the Bioactivities of Japanese and Bohemian Knotweed Ethanol Extracts." Foods 9, no. 5: 544.