EJPAU 2006. Gumul D. , Korus J. POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY OF RYE BRAN EXTRUDATES PRODUCED AT VARYING PARAMETERS OF EXTRUSION PROCESS

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.

2006
Volume 9
Issue 4

Topic:

Food Science and Technology

ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES

Gumul D. , Korus J. 2006. POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY OF RYE BRAN EXTRUDATES PRODUCED AT VARYING PARAMETERS OF EXTRUSION PROCESS, EJPAU 9(4), #11.
Available Online: http://www.ejpau.media.pl/volume9/issue4/abs-11.html

POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY OF RYE BRAN EXTRUDATES PRODUCED AT VARYING PARAMETERS OF EXTRUSION PROCESS

Dorota Gumul, Jarosław Korus
Department of Carbohydrates Technology, Agricultural University of Cracow, Poland

ABSTRACT

Extrusion, a popular method of cereal processing, increases the amounts of phenolic acids in cereal grain. These compounds protect the human body from oxidation stress and prevent the development of chronic diseases. The present study determined the composition of phenolic acids in rye bran after extrusion and defined the antioxidant activity of the extrudates. The bran was obtained through the laboratory milling of the grain of three rye cultivars, namely Amilo, Rostockie and Agrikolo. Extrusion was performed in a single-screw laboratory extruder Brabender 20 DN equipped with a 3:1 screw and a 3 mm die. Screw speed was maintained at 190 rpm while two temperature profiles, 80-100-120°C and 120-160-180°C, were applied. Prior to extrusion, the moisture of the rye bran to be processed was equilibrated to 14 or 20%.

The main phenolic acid found in rye bran was ferulic acid. Irrespective of rye cultivar and the parameters of processing, the ferulic acid and diferulic acid contents increased two times, and the p-coumaric acid content increased by 70% due to extrusion. The levels of other phenolic acids and apigenin decreased or did not change. The exception was caffeic acid whose amount in extrudates was higher than in bran for the Amilo and Rostockie cultivars and was lower for Agrikolo. Using a 14% moisture of the original material and a temperature of 120 or 180°C as parameters of the extrusion process produced the highest antioxidant activity of rye bran extrudates.

Key words: antioxidant activity, phenolic acids, rye bran extrudates.

Dorota Gumul
Department of Carbohydrates Technology,
Agricultural University of Cracow, Poland
Balicka 122, 30-149 Cracow, Poland
Phone: (+48 12) 662 47 71
Fax: (+48 12) 662 47 47
email: rrgumul@cyf-kr.edu.pl

Jarosław Korus
Department of Carbohydrates Technology,
Agricultural University of Cracow, Poland
Balicka 122, 30-149 Cracow, Poland
ph./fax: (+48 12) 662 47 47
email: rrkorus@cyf-kr.edu.pl

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.