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Zawartość związków biologicznie czynnych w wybranych typach kawy z produkcji ekologicznej i konwencjonalnej

Hallmann M., Ożga, Rembiałkowska E.

Journal of Research and Applications in Agricultural Engineering

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2010

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Vol. 55, nr 3

99-104

PL

Kawa jest bardzo ważnym elementem codziennego jadłospisu konsumentów w Polsce i na świecie. Jej składniki działają ożywczo i pobudzająco na organizm człowieka, ponadto jako bogaty wachlarz związków fenolowych działają prozdrowotnie. Celem pracy było porównanie zawartości związków bioaktywnych z grupy kwasów fenolowych i flawonoidów w kawach z produkcji ekologicznej i konwencjonalnej. Otrzymane wyniki wskazują, że w przypadku kaw typu instant stwierdzono wystąpienie znacznie większych różnic w zawartości związków biologicznie czynnych w zależności od systemu produkcji polowej niż w przypadku kaw mielonych. Ekologiczne kawy typu instant zawierały istotnie więcej kofeiny, kwasu chlorogenowego, galusanu epigalokatechiny, rutyny, D-glikozydu kwercetyny, myricetyny i naringiny w porównaniu z konwencjonalnymi kawami typu instant. Konwencjonalne kawy typu instant zawierały istotnie więcej flawon-3-oli oraz kwasu kawowego w porównaniu z kawami ekologicznymi typu instant. Ekologiczne kawy mielone zawierały istotnie więcej suchej masy, natomiast istotnie mniej rutyny i D-glikozydu kwercetyny w porównaniu z kawami mielonymi z produkcji konwencjonalnej. Kawy typu instant zawierały istotnie więcej prawie wszystkich analizowanych substancji w porównaniu z kawami mielonymi z wyjątkiem rutyny, której było istotnie więcej w kawach mielonych. Przyczyną tych różnic jest prawdopodobnie zupełnie inny sposób produkcji kaw typu instant. Należy kontynuować badania nad zawartością związków bioaktywnych w kawach z produkcji ekologicznej z uwagi na zupełny brak tego typu danych w literaturze oraz bardzo duże znaczenie kawy w codziennym spożyciu konsumentów.

EN

Coffee is very important ingredient of daily menu of the most consumers in Poland and world. Coffee's components are refreshing and stimulating for human organism, moreover containing the range of phenolic substances they are healthful. The aim of work was to compare the content of bioactive compounds as phenolic acids and flavonoides in the coffees from the organic and conventional production. The results show that in the instant coffees the differences between organic vs conventional production system are much higher than in the ground coffees. Organic instant coffees contained significantly more caffeine, chlorogenic acid, epigallocatechin gallate, rutin, D-glycoside of quercetin, myricetin, and naringin than conventional instant coffees. Conventional instant coffees contained significantly more flavon-3-ols and caffeic acid than organic instant coffees. Organic ground coffees contained significantly more dry matter and significantly less rutin and Dglycoside of quercetin than conventional ground coffees. Instant coffees contained significantly and much more almost all of the analyzed substances than ground coffees except rutin that was significantly more abundant in ground coffees. The reason for such big differences is probably completely different production procedure of the instant coffees. The studies on the content of the bioactive compounds in the coffees from organic vs conventional production should be continued in view of total lack of such scientific data and high importance of coffee in the everyday consumption.

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Consequences of Covalent and Non-Covalent Interactions on Conformational Preferences and pi-Electron Delocalization for the Substrate (Pyruvate) and Inhibitor (Oxamate) of Lactate Dehydrogenase - DFT Studies

Raczyńska E. D., Hallmann M., Duczmal K.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 5

1077-1090

EN

Conformational preferences and pi-electron delocalization for the isolated substrate (pyruvate) and inhibitor (oxamate) of lactate dehydrogenase (LDH), their protonated forms, adducts with alkali metal cations, and complexes with imidazole and/or the guanidinium cation (models for His195 and Arg171 of the LDH pocket, respectively) have been investigated at the DFT(B3LYP)/6-31++G(d,p) level. Covalent and non covalent bonds in acids, adducts and complexes cause greater conformational changes for pyruvate than for oxamate. Delocalization of pi electrons for the OCO frag ments is similar for similar structures. For isolated anions, adducts and complexes, the HOMED(OCO) values are between 0.9 and 1.0. For protonated forms, the HOMED(OCO) val ues are re duced to 0.55-0.75. Delocalization of pi electrons for the CCO fragment in pyruvate and for the NCO fragment in oxamate in creases when the anions form covalent and non-covalent bonds with other ions and molecules. The HOMED(CCO) values vary from 0.1 to 0.5 forsigma-pi conjugated pyruvate, whereas the HOMED(NCO) values vary from 0.9 to 1.0 for n-pi conjugated oxamate.

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Tautomeric Equilibria and pi-Electron Delocalization for the Substrate (Pyruvate) and Inhibitor (Oxamate) of Lactate Dehydrogenase - DFT Studies

Raczyńska E. D., Duczmal K., Hallmann M.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 9

1655-1666

EN

Keto-enol tautomerism for the substrate (pyruvate) of lactate dehydrogenase (LDH) and amideiminol tautomerism for its inhibitor (oxamate) were studied at the DFT(B3LYP)/6-31++G(d,p) level. Both anions (and also both radicals) prefer the C=O forms, i.e. the keto and amide form, respectively. The OH forms (enolpyruvate and iminoloxamate) have higher Gibbs free energies. Their amounts in the tautomeric mixtures are larger than 0.01% for anions and lower than 0.001% for radicals. pi-Electron delocalization for OCO fragments is greater than that for XCO fragments for both anions and radicals.

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Comparison of the Proton (H+) and Alkali Metal Ion (Li+, Na+ and K+) Binding Affinities of Pyruvate and Oxamate Anions in the Gas Phase. Quantum-Chemical Studies

Duczmal K., Hallmann M., Raczynska E., Gal F., Maria P.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 5-6

1011-1020

EN

Proton affinity (PA), lithium, sodium and potassium cation affinities (CA) in the gas phase were estimated by Gaussian-2 (G2), Möller-Plesset (MP2) methods and/or hybrid density functional theory calculations (B3LYP) for pyruvate and oxamate anions. Comparison of these affinities shows that the COO– groups of both anions have similar basicities. Differences between their calculated PAs as well as between their calculated CAs are not larger than 3 kcal mol–1. Somewhat larger differences are evidenced for the formations of the alkali metal complexes with the cation located between the oxygen atoms of the alfaC=O and COO– groups for which the lithium, sodium and potassium cation affinities are larger for oxamate than for pyruvate (by 40.5 kcal mol–1 at theG2 level and by 60.5 kcal mol–1 at the DFT(B3LYP)/6-31++G** level). This is a consequence of the chelate effect on the cation binding seen on the calculatedmost stable structures of the adducts.