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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.
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.
The aim was to investigate the effects of the cold dehulling of buckwheat seeds on their germination, total phenolic content (TPC), antioxidant activity (AA) and phenolics composition. Cold dehulling had no negative effects on germination rate and resulted in faster rootlet growth compared to hulled seeds. Although the dehulling of the seeds significantly decreased TPC and AA, the germination of dehulled seeds resulted in 1.8-fold and 1.9-fold higher TPC and AA compared to hulled seeds. Liquid chromatography coupled to mass spectrometry identified several phenolic compounds in free and bound forms. Rutin was the major compound in hulled seeds (98 µg/g dry weight), orientin and vitexin in 96-h germinated dehulled seeds (2205, 1869 µg/g dry weight, respectively). During germination, the increases in the major phenolic compounds were around two orders of magnitude, which were greater than the increases for TPC and AA. As well as orientin and vitexin, high levels of other phenolic compounds were detected for dehulled germinated seeds (e.g., isoorientin, rutin; 1402, 967 µg/g dry weight, respectively). These data show that dehulled germinated seeds of buckwheat have great potential for use in functional foods as a dietary source of phenolic compounds with health benefits.
Andrej Živković; Tomaž Polak; Blaž Cigić; Tomaž Požrl. Germinated Buckwheat: Effects of Dehulling on Phenolics Profile and Antioxidant Activity of Buckwheat Seeds. Foods 2021, 10, 740 .
AMA StyleAndrej Živković, Tomaž Polak, Blaž Cigić, Tomaž Požrl. Germinated Buckwheat: Effects of Dehulling on Phenolics Profile and Antioxidant Activity of Buckwheat Seeds. Foods. 2021; 10 (4):740.
Chicago/Turabian StyleAndrej Živković; Tomaž Polak; Blaž Cigić; Tomaž Požrl. 2021. "Germinated Buckwheat: Effects of Dehulling on Phenolics Profile and Antioxidant Activity of Buckwheat Seeds." Foods 10, no. 4: 740.
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.
Doris Kokalj; Emil Zlatić; Blaž Cigić; Matej Bernard Kobav; Rajko Vidrih. Postharvest flavonol and anthocyanin accumulation in three apple cultivars in response to blue-light-emitting diode light. Scientia Horticulturae 2019, 257, 1 .
AMA StyleDoris Kokalj, Emil Zlatić, Blaž Cigić, Matej Bernard Kobav, Rajko Vidrih. Postharvest flavonol and anthocyanin accumulation in three apple cultivars in response to blue-light-emitting diode light. Scientia Horticulturae. 2019; 257 ():1.
Chicago/Turabian StyleDoris Kokalj; Emil Zlatić; Blaž Cigić; Matej Bernard Kobav; Rajko Vidrih. 2019. "Postharvest flavonol and anthocyanin accumulation in three apple cultivars in response to blue-light-emitting diode light." Scientia Horticulturae 257, no. : 1.
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 2019, 1 -40.
AMA StyleNataša Poklar Ulrih, Iztok Prislan, Blaž Cigić. Coumaric and Cinnamic Acids in Food. Handbook of Dietary Phytochemicals. 2019; ():1-40.
Chicago/Turabian StyleNataša Poklar Ulrih; Iztok Prislan; Blaž Cigić. 2019. "Coumaric and Cinnamic Acids in Food." Handbook of Dietary Phytochemicals , no. : 1-40.
Florijan Cajzek; Jasna Bertoncelj; Ivan Kreft; Nataša Poklar Ulrih; Tomaž Polak; Tomaž Požrl; Igor Pravst; Ivana Polišenská; Kateřina Vaculová; Blaž Cigić. Preparation of β‐glucan and antioxidant‐rich fractions by stone milling of hull‐less barley. International Journal of Food Science & Technology 2019, 55, 681 -689.
AMA StyleFlorijan Cajzek, Jasna Bertoncelj, Ivan Kreft, Nataša Poklar Ulrih, Tomaž Polak, Tomaž Požrl, Igor Pravst, Ivana Polišenská, Kateřina Vaculová, Blaž Cigić. Preparation of β‐glucan and antioxidant‐rich fractions by stone milling of hull‐less barley. International Journal of Food Science & Technology. 2019; 55 (2):681-689.
Chicago/Turabian StyleFlorijan Cajzek; Jasna Bertoncelj; Ivan Kreft; Nataša Poklar Ulrih; Tomaž Polak; Tomaž Požrl; Igor Pravst; Ivana Polišenská; Kateřina Vaculová; Blaž Cigić. 2019. "Preparation of β‐glucan and antioxidant‐rich fractions by stone milling of hull‐less barley." International Journal of Food Science & Technology 55, no. 2: 681-689.
D. Kokalj; D. Gođevac; Boban Anđelković; Blaž Cigić; E. Zlatić; J. Hribar; R. Vidrih. Nuclear magnetic resonance as a tool for the assessment of postharvest changes in the metabolome of the skin of sweet cherry (Prunus avium L.). Acta Horticulturae 2019, 483 -488.
AMA StyleD. Kokalj, D. Gođevac, Boban Anđelković, Blaž Cigić, E. Zlatić, J. Hribar, R. Vidrih. Nuclear magnetic resonance as a tool for the assessment of postharvest changes in the metabolome of the skin of sweet cherry (Prunus avium L.). Acta Horticulturae. 2019; (1235):483-488.
Chicago/Turabian StyleD. Kokalj; D. Gođevac; Boban Anđelković; Blaž Cigić; E. Zlatić; J. Hribar; R. Vidrih. 2019. "Nuclear magnetic resonance as a tool for the assessment of postharvest changes in the metabolome of the skin of sweet cherry (Prunus avium L.)." Acta Horticulturae , no. 1235: 483-488.
Alberto Fiore; Blaž Cigić; Vito Verardo. Bioactive Compounds from Food Byproducts. Journal of Food Quality 2019, 2019, 1 -2.
AMA StyleAlberto Fiore, Blaž Cigić, Vito Verardo. Bioactive Compounds from Food Byproducts. Journal of Food Quality. 2019; 2019 ():1-2.
Chicago/Turabian StyleAlberto Fiore; Blaž Cigić; Vito Verardo. 2019. "Bioactive Compounds from Food Byproducts." Journal of Food Quality 2019, no. : 1-2.
Light influences postharvest formation of bioactive compounds in fruit and vegetables. The objectives of this study were to determine the physicochemical changes and phenylalanine ammonia lyase and flavonoid 3′-hydroxylase activities in sweet cherries (Prunus avium L.) irradiated with light-emitting diodes. Cherries were stored under light-emitting diodes for 10 days, exposed to UV-B and blue light, and to the combination of white, blue and green light. Irradiation with blue light significantly increased the anthocyanin content (cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside) and significantly influenced the CIE color parameters hue, C* and ΔE. Combined white-blue-green light provoked similar but less pronounced effects, while UV-B light was similar to control (in the dark). Blue and white-blue-green light increased phenylalanine ammonia lyase activity. Light irradiation had no significant effects on ascorbic acid and the phenolic profile. Highly significant correlations were found between anthocyanins and phenylalanine ammonia lyase on the one side, and the color parameters hue, C* and ΔE on the other.
Doris Kokalj; Emil Zlatić; Blaž Cigić; Rajko Vidrih. Postharvest light-emitting diode irradiation of sweet cherries (Prunus avium L.) promotes accumulation of anthocyanins. Postharvest Biology and Technology 2018, 148, 192 -199.
AMA StyleDoris Kokalj, Emil Zlatić, Blaž Cigić, Rajko Vidrih. Postharvest light-emitting diode irradiation of sweet cherries (Prunus avium L.) promotes accumulation of anthocyanins. Postharvest Biology and Technology. 2018; 148 ():192-199.
Chicago/Turabian StyleDoris Kokalj; Emil Zlatić; Blaž Cigić; Rajko Vidrih. 2018. "Postharvest light-emitting diode irradiation of sweet cherries (Prunus avium L.) promotes accumulation of anthocyanins." Postharvest Biology and Technology 148, no. : 192-199.
Trolox, gallic acid, chlorogenic acid, caffeic acid, catechin, epigallocatechin gallate, and ascorbic acid are antioxidants used as standards for reaction with chromogenic radicals, 2,2-diphenyl-1-picrylhydrazyl (DPPH⋅) and 2,2′-azino-bis-3-ethylbenzotiazolin-6-sulfonic acid (ABTS⋅+), and Folin–Ciocalteu (FC) reagent. The number of exchanged electrons has been analyzed as function of method and solvent. A majority of compounds exchange more electrons in FC assay than in ABTS and DPPH assays. In reaction with chromogenic radicals, the largest number of electrons was exchanged in buffer (pH 7.4) and the lowest reactivity was in methanol (DPPH) and water (ABTS). At physiological pH, the number of exchanged electrons of polyphenols exceeded the number of OH groups, pointing to the important contribution of partially oxidized antioxidants, formed in the course of reaction, to the antioxidant potential. For Trolox, small impact on the number of exchanged electrons was observed, confirming that it is more suitable as a standard compound than the other antioxidants.
Helena Abramovič; Blaž Grobin; Nataša Poklar Ulrih; Blaž Cigić. Relevance and Standardization of In Vitro Antioxidant Assays: ABTS, DPPH, and Folin–Ciocalteu. Journal of Chemistry 2018, 2018, 1 -9.
AMA StyleHelena Abramovič, Blaž Grobin, Nataša Poklar Ulrih, Blaž Cigić. Relevance and Standardization of In Vitro Antioxidant Assays: ABTS, DPPH, and Folin–Ciocalteu. Journal of Chemistry. 2018; 2018 ():1-9.
Chicago/Turabian StyleHelena Abramovič; Blaž Grobin; Nataša Poklar Ulrih; Blaž Cigić. 2018. "Relevance and Standardization of In Vitro Antioxidant Assays: ABTS, DPPH, and Folin–Ciocalteu." Journal of Chemistry 2018, no. : 1-9.
Antioxidant potential (AOP) is not only the property of the matrix analyzed but also depends greatly on the methodology used. The 2,2'-azino-bis-3-etilbenzotiazolin-6-sulfonic acid (ABTS•+), 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and Folin-Ciocalteu (FC) methods were applied to estimate how the method and the composition of the assay solvent influence the AOP determined for coffee, tea, beer, apple juice and dietary supplements. Large differences between the AOP values depending on the reaction medium were observed, with the highest AOP determined mostly in the FC assay. In reactions with chromogenic radicals several fold higher values of AOP were obtained in buffer pH 7.4 than in water or methanol. The type of assay and solvent composition have similar influences on the reactivity of a particular antioxidant, either pure or as part of a complex matrix. The reaction kinetics of radicals with antioxidants in samples reveals that AOP depends strongly on incubation time, yet differently for each sample analyzed and the assay applied.
Helena Abramovič; Blaž Grobin; Nataša Poklar Ulrih; Blaž Cigić. The Methodology Applied in DPPH, ABTS and Folin-Ciocalteau Assays Has a Large Influence on the Determined Antioxidant Potential. Acta Chimica Slovenica 2017, 64, 491 -499.
AMA StyleHelena Abramovič, Blaž Grobin, Nataša Poklar Ulrih, Blaž Cigić. The Methodology Applied in DPPH, ABTS and Folin-Ciocalteau Assays Has a Large Influence on the Determined Antioxidant Potential. Acta Chimica Slovenica. 2017; 64 (2):491-499.
Chicago/Turabian StyleHelena Abramovič; Blaž Grobin; Nataša Poklar Ulrih; Blaž Cigić. 2017. "The Methodology Applied in DPPH, ABTS and Folin-Ciocalteau Assays Has a Large Influence on the Determined Antioxidant Potential." Acta Chimica Slovenica 64, no. 2: 491-499.
Aminopeptidases, together with other proteases, execute and regulate the total and specifically limited protein breakdown involved in plant physiology, raising the possibility of their involvement in response to drought. We have identified, in leaves of Phaseolus vulgaris L., five aminopeptidases (E.C.3.4.11) whose levels of activity changed when three week old plants were subjected to drought. First, second and third trifoliate leaves were investigated separately. The aminopeptidases were first identified then isolated using ion exchange chromatography of leaf extracts. Three, named PvAP1, PvAP2 and PvAP4, are metallo aminopeptidases with broad substrate specificity, active against substrates conjugated to alanine and lysine. Two others, PvAP3 and PvAP5, are apparently serine aminopeptidases, the former active against substrates conjugated to phenylalanine and leucine, and the latter characterised by narrow specificity against substrates conjugated to phenylalanine. Their apparent molecular weights range from ∼37 kDa to ∼80 kDa. Levels of activity of individual aminopeptidases in both watered and drought stressed plants are shown to depend on the age of leaves. In watered plants they were generally highest in young, and very low in older, trifoliate leaves, the latter with the exception of PvAP5. Drought initiated an almost general increase of their activities, although to different extents, with the exception of PvAP4 and PvAP5 in young trifoliate leaves. Thus, in such studies it is necessary to investigate the effects of drought separately in leaves of different ages in order to elucidate the different complex and probably specific roles of aminopeptidases in the response of common bean to drought.
Maruška Budič; Blaž Cigić; Maja Šoštarič; Jerica Sabotič; Vladimir Meglič; Janko Kos; Marjetka Kidrič. The response of aminopeptidases of Phaseolus vulgaris to drought depends on the developmental stage of the leaves. Plant Physiology and Biochemistry 2016, 109, 326 -336.
AMA StyleMaruška Budič, Blaž Cigić, Maja Šoštarič, Jerica Sabotič, Vladimir Meglič, Janko Kos, Marjetka Kidrič. The response of aminopeptidases of Phaseolus vulgaris to drought depends on the developmental stage of the leaves. Plant Physiology and Biochemistry. 2016; 109 ():326-336.
Chicago/Turabian StyleMaruška Budič; Blaž Cigić; Maja Šoštarič; Jerica Sabotič; Vladimir Meglič; Janko Kos; Marjetka Kidrič. 2016. "The response of aminopeptidases of Phaseolus vulgaris to drought depends on the developmental stage of the leaves." Plant Physiology and Biochemistry 109, no. : 326-336.
The impact of malting on the profile of the phenolic compounds and the antioxidant properties of two buckwheat varieties was investigated. The highest relative increases in phenolic compounds were observed for isoorientin, orientin, and isovitexin, which are consequently major inducible phenolic compounds during malting. Only a minor relative increase was observed for the most abundant phenolic compound, rutin. The radical-scavenging activity of buckwheat seeds was evaluated using ABTS and DPPH assays. A considerable increase in total phenolic compounds and higher antioxidant activity were observed after 64 h of germination, whereas kilning resulted in decreased total phenolic compounds and antioxidant activity. Higher antioxidant activities for extracts were found for buffered solvents than for pure methanol and water. Changes in the composition of the phenolic compounds and increased antioxidant content were confirmed by several methods, indicating that buckwheat malt can be used as a food rich in antioxidants.
Petra Terpinc; Blaž Cigić; Tomaž Polak; Janez Hribar; Tomaž Požrl. LC–MS analysis of phenolic compounds and antioxidant activity of buckwheat at different stages of malting. Food Chemistry 2016, 210, 9 -17.
AMA StylePetra Terpinc, Blaž Cigić, Tomaž Polak, Janez Hribar, Tomaž Požrl. LC–MS analysis of phenolic compounds and antioxidant activity of buckwheat at different stages of malting. Food Chemistry. 2016; 210 ():9-17.
Chicago/Turabian StylePetra Terpinc; Blaž Cigić; Tomaž Polak; Janez Hribar; Tomaž Požrl. 2016. "LC–MS analysis of phenolic compounds and antioxidant activity of buckwheat at different stages of malting." Food Chemistry 210, no. : 9-17.
The objective of this study is to investigate the effects of irradiation from light-emitting diodes (LEDs) on several fruits during storage. To improve storage and increase the contents of some bioactive compounds, apple, tomato and red bell pepper fruits were exposed to yellow light emitted from the diodes at 590 nm. The contents of ascorbic acid, total phenolics, total flavonoids and several pigments were investigated, along with the antioxidant potential. The colour parameters (L*, a* and b*) and firmness of the fruit were also determined. After 7 days of LED light irradiation, there was significantly higher total phenolic content and antioxidant potential in apple peel extracts. The irradiated fruit of tomato had significantly higher levels of total phenolic compounds, and the fruit of red bell pepper had significantly higher antioxidant potential. LED light had no effects on the colour parameters, although there was a tendency to accelerate colour development. Apple fruit irradiated with LED light was significantly less firm. Among twelve analysed pigments, significantly more β-carotene was detected in LED light-irradiated apple and bell pepper fruit, more α-tocopherol and γ-tocopherol in bell pepper fruit, and more lutein in apple peel and bell pepper fruit. The applied LED light slightly accelerated the ripening of the studied fruit, and affected the synthesis of some of the secondary metabolites.
Doris Kokalj; Janez Hribar; Blaž Cigić; Emil Zlatić; Lea Demšar; Lovro Sinkovič; Helena Šircelj; Grega Bizjak; Rajko Vidrih. Influence of Yellow Light-Emitting Diodes at 590 nm on Storage of Apple, Tomato and Bell Pepper Fruit. Food Technology and Biotechnology 2016, 54, 228 -235.
AMA StyleDoris Kokalj, Janez Hribar, Blaž Cigić, Emil Zlatić, Lea Demšar, Lovro Sinkovič, Helena Šircelj, Grega Bizjak, Rajko Vidrih. Influence of Yellow Light-Emitting Diodes at 590 nm on Storage of Apple, Tomato and Bell Pepper Fruit. Food Technology and Biotechnology. 2016; 54 (2):228-235.
Chicago/Turabian StyleDoris Kokalj; Janez Hribar; Blaž Cigić; Emil Zlatić; Lea Demšar; Lovro Sinkovič; Helena Šircelj; Grega Bizjak; Rajko Vidrih. 2016. "Influence of Yellow Light-Emitting Diodes at 590 nm on Storage of Apple, Tomato and Bell Pepper Fruit." Food Technology and Biotechnology 54, no. 2: 228-235.
The intensity of mechanical stress and the temperature significantly affect the levels of individual and total glucosinolates in shredded white cabbage (cv. Galaxy). Mild processing (shredding to 2 mm thickness) at 8°C resulted in the accumulation of glucosinolates (40% increase) in comparison with unshredded cabbage, which was already seen 5 min after the mechanical stress. Severe processing (shredding to 0.5 mm thickness) at 20°C, however, resulted in an initial 50% decrease in glucosinolates. The glucosinolates accumulated in all of the cabbage samples 30 min from processing, resulting in higher levels than in unshredded cabbage, except for the severe processing at 20°C where the increase was not sufficient to compensate for the initial loss. Glucobrassicin and neoglucobrassicin were the major glucosinolates identified in the cabbage samples. Mechanical stress resulted in an increase in the relative proportion of glucobrassicin and in a decrease in neoglucobrassicin.
Tomaž Požrl; Blaž Cigić; Lea Demšar; Janez Hribar; Tomaž Polak. Mechanical Stress Results in Immediate Accumulation of Glucosinolates in Fresh-Cut Cabbage. Journal of Chemistry 2015, 2015, 1 -7.
AMA StyleTomaž Požrl, Blaž Cigić, Lea Demšar, Janez Hribar, Tomaž Polak. Mechanical Stress Results in Immediate Accumulation of Glucosinolates in Fresh-Cut Cabbage. Journal of Chemistry. 2015; 2015 ():1-7.
Chicago/Turabian StyleTomaž Požrl; Blaž Cigić; Lea Demšar; Janez Hribar; Tomaž Polak. 2015. "Mechanical Stress Results in Immediate Accumulation of Glucosinolates in Fresh-Cut Cabbage." Journal of Chemistry 2015, no. : 1-7.
The reactivity of tocopherols with 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied in model systems in order to establish a method for quantifying vitamin E in plant oils. The method was optimized with respect to solvent composition of the assay medium, which has a large influence on the course of reaction of tocopherols with DPPH. The rate of reaction of α-tocopherol with DPPH is higher than that of γ-tocopherol in both protic and aprotic solvents. In ethyl acetate, routinely applied for the analysis of antioxidant potential (AOP) of plant oils, reactions of tocopherols with DPPH are slower and concentration of tocopherols in the assay has a large influence on their molar reactivity. In 2-propanol, however, two electrons are exchanged for both α- and γ-tocopherols, independent of their concentration. 2-propanol is not toxic and is fully compatible with polypropylene labware. The chromatographically determined content of tocopherols and their molar reactivity in the DPPH assay reveal that only tocopherols contribute to the AOP of sunflower oil, whereas the contribution of tocopherols to the AOP of linseed oil is 75%. The DPPH assay in 2-propanol can be applied for rapid and cheap estimation of vitamin E content in plant oils where tocopherols are major antioxidants.
Tjaša Prevc; Alenka Levart; Irena Kralj Cigić; Janez Salobir; Natasa Poklar Ulrih; Blaž Cigić. Rapid Estimation of Tocopherol Content in Linseed and Sunflower Oils-Reactivity and Assay. Molecules 2015, 20, 14777 -14790.
AMA StyleTjaša Prevc, Alenka Levart, Irena Kralj Cigić, Janez Salobir, Natasa Poklar Ulrih, Blaž Cigić. Rapid Estimation of Tocopherol Content in Linseed and Sunflower Oils-Reactivity and Assay. Molecules. 2015; 20 (8):14777-14790.
Chicago/Turabian StyleTjaša Prevc; Alenka Levart; Irena Kralj Cigić; Janez Salobir; Natasa Poklar Ulrih; Blaž Cigić. 2015. "Rapid Estimation of Tocopherol Content in Linseed and Sunflower Oils-Reactivity and Assay." Molecules 20, no. 8: 14777-14790.
Tjaša Prevc; Nataša Šegatin; Polonca Kralj; Nataša Poklar Ulrih; Blaž Cigić. Influence of metal ions and phospholipids on electrical properties: A case study on pumpkin seed oil. Food Control 2015, 54, 287 -293.
AMA StyleTjaša Prevc, Nataša Šegatin, Polonca Kralj, Nataša Poklar Ulrih, Blaž Cigić. Influence of metal ions and phospholipids on electrical properties: A case study on pumpkin seed oil. Food Control. 2015; 54 ():287-293.
Chicago/Turabian StyleTjaša Prevc; Nataša Šegatin; Polonca Kralj; Nataša Poklar Ulrih; Blaž Cigić. 2015. "Influence of metal ions and phospholipids on electrical properties: A case study on pumpkin seed oil." Food Control 54, no. : 287-293.
The reactivity of SO2 with the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and in Folin Ciocalteu (FC) assays was analysed under different experimental conditions. There was significantly higher reactivity between SO2 and DPPH in buffered methanol than in methanol alone. When DPPH and FC assays were performed in a mixture of caftaric acid and SO2, there were synergistic effects that were more pronounced with the FC assay. Phenolics are an important parameter of wine quality, and their accurate characterisation in wine is essential. Analysis of white wines with DPPH and FC assays overestimates the contribution of phenolics to the antioxidant potential (AOP). SO2 contributes (from 20% to 45%) to the AOP of the white wines analysed. As SO2 reactivity depends highly on buffer composition, pH, time of incubation and other compounds, e.g. phenolics and aldehydes, different experimental protocols can produce large variations in AOPs, and therefore control of experimental conditions is extremely important.
Helena Abramovič; Tatjana Košmerl; Nataša Poklar Ulrih; Blaž Cigić. Contribution of SO2 to antioxidant potential of white wine. Food Chemistry 2015, 174, 147 -153.
AMA StyleHelena Abramovič, Tatjana Košmerl, Nataša Poklar Ulrih, Blaž Cigić. Contribution of SO2 to antioxidant potential of white wine. Food Chemistry. 2015; 174 ():147-153.
Chicago/Turabian StyleHelena Abramovič; Tatjana Košmerl; Nataša Poklar Ulrih; Blaž Cigić. 2015. "Contribution of SO2 to antioxidant potential of white wine." Food Chemistry 174, no. : 147-153.
Model vegetable oil mixtures with significantly different basic oil quality indices (free fatty acid, iodine, and Totox values) were prepared by adding oleic acids, synthetic saturated triglycerides, or oxidized safflower oil (Carthamus tinctorius) to the oleic type of sunflower oil. Dielectric constants, dielectric loss factors, quality factors, and electrical conductivities of model lipids were determined at frequencies from 50 Hz to 2 MHz and at temperatures from 293.15 to 323.15 K. The dependence of these dielectric parameters on basic oil quality indices was investigated. Adding oleic acids to sunflower oil resulted in lower dielectric constants and conductivities and higher quality factors. Reduced iodine values resulted in increased dielectric constants and quality factors and decreased conductivities. Higher Totox values resulted in higher dielectric constants and conductivities at high frequencies and lower quality factors. Dielectric constants decreased linearly with temperature, whereas conductivities followed the Arrhenius law.
Tjaša Prevc; Blaž Cigić; Rajko Vidrih; Nataša Poklar Ulrih; Nataša Šegatin. Correlation of Basic Oil Quality Indices and Electrical Properties of Model Vegetable Oil Systems. Journal of Agricultural and Food Chemistry 2013, 61, 11355 -11362.
AMA StyleTjaša Prevc, Blaž Cigić, Rajko Vidrih, Nataša Poklar Ulrih, Nataša Šegatin. Correlation of Basic Oil Quality Indices and Electrical Properties of Model Vegetable Oil Systems. Journal of Agricultural and Food Chemistry. 2013; 61 (47):11355-11362.
Chicago/Turabian StyleTjaša Prevc; Blaž Cigić; Rajko Vidrih; Nataša Poklar Ulrih; Nataša Šegatin. 2013. "Correlation of Basic Oil Quality Indices and Electrical Properties of Model Vegetable Oil Systems." Journal of Agricultural and Food Chemistry 61, no. 47: 11355-11362.