Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2005
Volume 8
Issue 4
Topic:
Food Science and Technology
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Gramza-Michałowska A. , Wójciak R. , Korczak J. , Hę¶ M. , Wi¶niewska J. , Krejpcio Z. 2005. INFLUENCE OF THE FE AND CU PRESENCE IN TEA EXTRACTS ON ANTIOXIDANT ACTIVITY, EJPAU 8(4), #30.
Available Online: http://www.ejpau.media.pl/volume8/issue4/abs-30.html

INFLUENCE OF THE FE AND CU PRESENCE IN TEA EXTRACTS ON ANTIOXIDANT ACTIVITY

Anna Gramza-Michałowska1, Rafał W. Wójciak2, Józef Korczak3, Marzanna Hę¶3, Julia Wi¶niewska2, Zbigniew Krejpcio2
1 Department of Food Service and Catering, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland
2 Department of Food Hygiene and Human Nutrition, The August Cieszkowski Agricultural University of Poznan, Poland
3 Department of Food Technology and Human Nutrition, The August Cieszkowski Agricultural University of Poznan, Poland

 

ABSTRACT



Tea leaves (Camelia sinensis L.) were extracted with two different solvents, namely water and ethanol. The absorptive atomic spectrometry technique – ASA was used to analyze the quantities of Fe and Cu in the tea extracts. Highest Cu level was marked in green tea ethanol extract. Fe content however was highest in black tea ethanol extract. Dependence of extracted Cu and Fe quantity from the solvent and tea leaf's genus was affirmed. Tea leaves can be the source of mineral components and trace elements, as well as the undesirable substances. Because both the iron and the copper can catalyze the oxidation processes, its presence is essential for the lipid stability. Metals content in lipids with addition of tea extracts shaped on level, which did not act prooxidatively. Cu content in lipid with green tea ethanol extract addition was five times higher; however Fe content in lipid with black tea ethanol extract addition was twice higher than in remaining samples. The result of tea extracts influence on oxidative stability of sunflower oil in Rancimat test showed best antioxidant activity in sample with green tea ethanol extract added.

Key words: tea extracts, Camelia sinensis, Cu, Fe, polyphenols, sunflower oil, Rancimat test.


Anna Gramza-Michałowska
Department of Food Service and Catering, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland
phone: +4861 848 7331
fax: +4861 848 7430
Wojska Polskiego 31
60-624 Poznań
Poland
email: angramza@up.poznan.pl

Rafał W. Wójciak
Department of Food Hygiene and Human Nutrition,
The August Cieszkowski Agricultural University of Poznan, Poland
Wojska Polskiego St. 28, 60-624 Poznan, Poland

Józef Korczak
Department of Food Technology and Human Nutrition,
The August Cieszkowski Agricultural University of Poznan, Poland
Wojska Polskiego St. 28, 60-624 Poznan, Poland

Marzanna Hę¶
Department of Food Technology and Human Nutrition,
The August Cieszkowski Agricultural University of Poznan, Poland
Wojska Polskiego St. 28, 60-624 Poznan, Poland

Julia Wi¶niewska
Department of Food Hygiene and Human Nutrition,
The August Cieszkowski Agricultural University of Poznan, Poland
Wojska Polskiego St. 28, 60-624 Poznan, Poland

Zbigniew Krejpcio
Department of Food Hygiene and Human Nutrition,
The August Cieszkowski Agricultural University of Poznan, Poland
Wojska Polskiego St. 28, 60-624 Poznan, Poland

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.