24 research outputs found

    Impact of food processing and interactions with other food components on the structure and function of food allergens

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    β-laktoglobulin (BLG) je glavni protein surutke mleka preživara, ali je prisutan i u mleku mnogih drugih vrsta sisara. Poznato je da BLG poseduje niz funkcionalnih osobina (npr. geliranje, stvaranje pene, emulzifikacija) važnih za industriju hrane kao i veliku nutritivnu vrednost zbog visokog sadržaja esencijalnih aminokiselina. Iz tog razloga se često koristi kao aditiv u prehrambenoj industriji. Međutim, BLG je jedan od glavnih alergena mleka; 45% pacijenata alergičnih na mleko reaguje na BLG. Stoga se sve više nameće potreba za razvijanje metoda za modifikaciju BLG-a u cilju smanjenja alergenosti i poboljšanja funkcionalnih osobina. Takođe, sva istraživanja u oblasti hrane ne smeju isključiti prisustvo drugih komponenti u matriksu hrane. Predmet rada ove teze je bio ispitivanje uticaja interakcija komponenti matriksa hrane (protein-polifenolna jedinjenja) i odabranih tehnika za obradu hrane (ultrazvuk i enzimsko umrežavanje) na strukturu i funkciju BLG-a. U okviru rada su okarakterisane nekovalentne interakcije između polifenolnih jedinjenja iz ekstrakata kafe, kakaoa, zelenog i crnog čaja i BLG-a. Pokazano je da se usled formiranja nekovalentnih interakcija između polifenolnih jedinjenja i BLG-a smanjuje digestibilnost proteina i da dolazi do maskiranja ukupnog antioksidativnog kapaciteta. Tretiranjem BLG-a ultrazvukom visokog intenziteta generisani su stabilni modifikati sa različitim promenama u sekundarnoj i tercijarnoj strukturi. Kontrolisanje temperature u toku tretmana je imalo odlučujući efekat na vrstu modifikacije. Izrazite promene u tercijarnoj strukturi BLG-a su dovele do formiranja polimera, gubitka afiniteta za vezivanje retinola i brže degradacije pepsinom. Promene u sekundarnoj strukturi nisu uslovile promene u digestibilnosti i vezivanju retinola. Afinitet sonifikovanih formi za vezivanje IgE antitela i indukciju IgE posredovane aktivacije bazofila i mastocita nije bio narušen...β-lactoglobulin (BLG) is the major whey protein of ruminant species, but is also present in the milk of many other species. It is well known that BLG has many benefitial functional properties such as gelling, foaming and emulsifying properties. Although, BLG is considered to be a valuable protein in view of nutritional science, and is frequently used as an additive in food industry, BLG is known to be a potent allergen responsible for milk allergy; around 45% of patients allergic to milk are sensitive to BLG. Hence, it is strongly desirable to develop new methods that would decrease the allergenicity and enhance the functional properties of BLG. Also, all the research in the field of food science can not exclude the presence of other components in the food matrix. The subject of this thesis was to examine the impact of the interactions formed between food matrix components (protein-polyphenol compounds) and selected food processing techniques (ultrasound and enzyme cross-linking) on the structure and function of BLG. In the paper, non-covalent interactions between polyphenolic compounds from extracts of coffee, cocoa, green and black tea and BLG are characterized. It is shown that due to the formation of non-covalent interactions between polyphenolic compounds and BLG, protein digestibility is reduced and total antioxidant capacity is masked. Treatment of BLG by high intensity ultrasound generated stable modified protein forms with marked changes in the secondary and tertiary structure. Temperature control during treatment had a determining effect on the type of modification. Striking changes in the tertiary structure of BLG led to the formation of polymers, the loss of affinity for retinol binding and degradation by pepsin. Alterations in the secondary structure did not cause changes in digestability and retinol binding..

    Predictability of aggressive cranial DAVF

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    Supplementary material for: [https://doi.org/10.1039/c4ra13230k]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1888

    Sojne razlike u toksičnosti antagoniste vitamina K varfarina kod pacova

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    Warfarin (3-(alpha-acetonylbenzy1)-4-hydroxy coumarin) is a vitamin K (VK) antagonist that inhibits vitamin K-dependent (VKD) processes, such as blood coagulation. It also exerts an influence on some non-VKD-related activities. In this study, the effect of sub-acute (30-day) oral warfarin (2 and 1 mg L-1) intake on hematological parameters was examined in two rat strains, Albino Oxford (AO) and Dark Agouti (DA), that differ in their sensitivity to certain chemicals. Greater susceptibility to the anticoagulant effect of 2 mg L-1 of warfarin was observed in AO rats and was associated with an increase in the relevant hematological parameters in this strain. Although both strains responded to 2 mg L-1 of warfarin with quantitative changes in the peripheral blood leukocytes, differential bone marrow and lung responses were observed. Strain-related differences in the pro-inflammatory activity of peripheral blood granulocytes and in mononuclear cell IFN-gamma production were observed. Recognition of differences in quantitative and qualitative effects of oral warfarin on processes other than hemostasis might be of relevance for those humans who are on warfarin therapy.Varfarin (3-α-acetonilbenzil)-4–hidroksikumarin) je antagonist vitamina K (VK) koji inhibira procese zavisne od ovog vitamina, uključujući koagulaciju krvi. Osim toga, on ispoljava i aktivnosti koje ne zavise od vitamina K kao što su anti-tumorska i imunomodulatorna aktivnost. U ovom radu je ispitan efekat subakutnog (30 dana) oralnog unosa varfarina na hematološke parametre i aktivnost leukocita periferne krvi kod dva soja pacova Albino Oxford (AO) i Dark Agouti (DA) koji se raz- likuju u osetljivosti na iste hemijske agense. Kod jedinki AO soja zapažena je veća smrtnost nakon konzumiranja doze od 4 mg L–1 kao i veća osetljivost na antikoagulantno dejstvo varfarina pri nižim dozama (2 mg L–1) koje je praćeno povećanjem nekih hematoloških parametara. Iako kod jedinki oba soja dolazi do povećanja broja neutrofilnih leukocita periferne krvi pri dozi od 2 mg L–1, promene u osnovnim proinflamatornim aktivnostima ovih ćelija su zapažene samo kod jedinki DA soja. Promene u broju neutrofilnih leukocita u krvi DA jedinki su praćene povećanjem broja granulocitnih prekursora u koštanoj srži, dok prisustvo neutrofila u plućima AO jedinki ukazuje na razmenu ćelija između periferne krvi i plućnog intravaskularnog pula ćelija. Diferencijalne sojno–zavisne promene u aktivnosti mononuklearnih ćelija periferne krvi su takođe zapažene. Razlike u efektu oralno unetog varfarina mogu da imaju implikacije za osobe na oralnoj varfarinskoj terapiji

    Role of resveratrol in prevention and control of cardiovascular disorders and cardiovascular complications related to COVID-19 disease: Mode of action and approaches explored to increase its bioavailability

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    Resveratrol is a phytoalexin produced by many plants as a defense mechanism against stress-inducing conditions. The richest dietary sources of resveratrol are berries and grapes, their juices and wines. Good bioavailability of resveratrol is not reflected in its high biological activity in vivo because of resveratrol isomerization and its poor solubility in aqueous solutions. Proteins, cyclodextrins and nanomaterials have been explored as innovative delivery vehicles for resveratrol to overcome this limitation. Numerous in vitro and in vivo studies demonstrated beneficial effects of resveratrol in cardiovascular diseases (CVD). Main beneficial effects of resveratrol intake are cardioprotective, anti-hypertensive, vasodilatory, anti-diabetic, and improvement of lipid status. As resveratrol can alleviate the numerous factors associated with CVD, it has potential as a functional supplement to reduce COVID-19 illness severity in patients displaying poor prognosis due to cardio-vascular complications. Resveratrol was shown to mitigate the major pathways involved in the pathogenesis of SARS-CoV-2 including regulation of the renin-angiotensin system and expression of angiotensin-converting enzyme 2, stimulation of immune system and downregulation of pro-inflammatory cytokine release. Therefore, several studies already have anticipated potential implementation of resveratrol in COVID-19 treatment. Regular intake of a resveratrol rich diet, or resveratrol-based complementary medicaments, may contribute to a healthier cardio-vascular system, prevention and control of CVD, including COVID-19 disease related complications of CVD

    Impact of food processing and interactions with other food components on the structure and function of food allergens

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    β-laktoglobulin (BLG) je glavni protein surutke mleka preživara, ali je prisutan i u mleku mnogih drugih vrsta sisara. Poznato je da BLG poseduje niz funkcionalnih osobina (npr. geliranje, stvaranje pene, emulzifikacija) važnih za industriju hrane kao i veliku nutritivnu vrednost zbog visokog sadržaja esencijalnih aminokiselina. Iz tog razloga se često koristi kao aditiv u prehrambenoj industriji. Međutim, BLG je jedan od glavnih alergena mleka; 45% pacijenata alergičnih na mleko reaguje na BLG. Stoga se sve više nameće potreba za razvijanje metoda za modifikaciju BLG-a u cilju smanjenja alergenosti i poboljšanja funkcionalnih osobina. Takođe, sva istraživanja u oblasti hrane ne smeju isključiti prisustvo drugih komponenti u matriksu hrane. Predmet rada ove teze je bio ispitivanje uticaja interakcija komponenti matriksa hrane (protein-polifenolna jedinjenja) i odabranih tehnika za obradu hrane (ultrazvuk i enzimsko umrežavanje) na strukturu i funkciju BLG-a. U okviru rada su okarakterisane nekovalentne interakcije između polifenolnih jedinjenja iz ekstrakata kafe, kakaoa, zelenog i crnog čaja i BLG-a. Pokazano je da se usled formiranja nekovalentnih interakcija između polifenolnih jedinjenja i BLG-a smanjuje digestibilnost proteina i da dolazi do maskiranja ukupnog antioksidativnog kapaciteta. Tretiranjem BLG-a ultrazvukom visokog intenziteta generisani su stabilni modifikati sa različitim promenama u sekundarnoj i tercijarnoj strukturi. Kontrolisanje temperature u toku tretmana je imalo odlučujući efekat na vrstu modifikacije. Izrazite promene u tercijarnoj strukturi BLG-a su dovele do formiranja polimera, gubitka afiniteta za vezivanje retinola i brže degradacije pepsinom. Promene u sekundarnoj strukturi nisu uslovile promene u digestibilnosti i vezivanju retinola. Afinitet sonifikovanih formi za vezivanje IgE antitela i indukciju IgE posredovane aktivacije bazofila i mastocita nije bio narušen...β-lactoglobulin (BLG) is the major whey protein of ruminant species, but is also present in the milk of many other species. It is well known that BLG has many benefitial functional properties such as gelling, foaming and emulsifying properties. Although, BLG is considered to be a valuable protein in view of nutritional science, and is frequently used as an additive in food industry, BLG is known to be a potent allergen responsible for milk allergy; around 45% of patients allergic to milk are sensitive to BLG. Hence, it is strongly desirable to develop new methods that would decrease the allergenicity and enhance the functional properties of BLG. Also, all the research in the field of food science can not exclude the presence of other components in the food matrix. The subject of this thesis was to examine the impact of the interactions formed between food matrix components (protein-polyphenol compounds) and selected food processing techniques (ultrasound and enzyme cross-linking) on the structure and function of BLG. In the paper, non-covalent interactions between polyphenolic compounds from extracts of coffee, cocoa, green and black tea and BLG are characterized. It is shown that due to the formation of non-covalent interactions between polyphenolic compounds and BLG, protein digestibility is reduced and total antioxidant capacity is masked. Treatment of BLG by high intensity ultrasound generated stable modified protein forms with marked changes in the secondary and tertiary structure. Temperature control during treatment had a determining effect on the type of modification. Striking changes in the tertiary structure of BLG led to the formation of polymers, the loss of affinity for retinol binding and degradation by pepsin. Alterations in the secondary structure did not cause changes in digestability and retinol binding..
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