I. G. Gökmen¹, O. Birgül¹, A. Kence² and A. Gökmen¹

Received: 3 August 1995  

Abstract  Like several other European countries, Turkey has been affected by the radioactive clouds arising from the Chemobyl reactor accident. There were two major fronts. The first one affected the western parts of Turkey, namely Thrace, Istanbul and Western Black Sea coast, starting from April 30th 1986. The second cloud affected the Eastern Black Sea coast at the beginning of May 1986. In both regions the clouds left their radioactive content with the heavy rains. Eastern Sea coast is one of the regions receiving highest volume of rainfall almost all year round. However, after the accident, the rains loaded with radioactive contaminants felt just before the tea collection period and the contaminated tea leaves were collected without finding a chance for cleaning with following rains. All of the tea consumed by Turkish people grows on a very narrow coastal line along the Eastern Black Sea. In this study, the results of radioactivity measurement on Turkish tea are summarized. Although there were other affected products in the region, e.g., hazelnuts, tobacco, vegetables, their level of contamination and yearly consumption rates were not as significant as tea. Tea is the major hot beverage consumed by Turkish people of all ages, but unfortunately it turned out to be one of the heavily contaminated products of Turkey. The effect of brewing and rinsing with hot water on tea were also investigated in the present work. The dose estimates from the tea consumption was done following a different approach than previous studies. Instead of using the radioactivity data obtained by measuring only limited number of contaminated tea samples in our laboratories, the data reported by the Turkish Atomic Energy Agency Authority covering all the tea product of 1986 were used for dose estimates. In addition the collective effective dose equivalent in Turkey was estimated. Although in this study contamination only in one product, namely tea, was discussed, it turned out to be important as it was consumed by large populations in Turkey, so contributed to the doses significantly. Precautions to be taken were summarized, one simple precaution rinsing of tea before brewing was sufficient to remove half of the contamination from tea without any drawbacks.

Dedicated to the memory of late Olcay Birgül.

The determination of optimum fermentation time in Turkish black tea manufacture

Mehmet Tüfekci and Saadettin Güner
Karadeniz Technical University, Department of Chemistry, 61080, Trabzon, Turkey
Received 12 April 1996;  revised 16 September 1996;  accepted 16 September 1996. ; Available online 9 December 1997.

Abstract

M. Gürü ^, and H. çen
Gazi University, Engineering and Architectural Faculty, Chemical Engineering Department, Ankara 06570, Maltepe, Turkey
Received 9 September 2003;  Revised 3 November 2003;  accepted 15 November 2003.  Available online 10 February 2004.

Abstract

The aim of this study was to find a cheap method to obtain caffeine. Experiments were performed on fiber and stalk wastes of Turkish tea plants that had no economical value other than being used merely as low grade fuel and fodder. Tea stalks and fiber were obtained from tea factories. Parameters affecting caffeine extraction from tea wastes were determined to be, mixing rate, water/tea ratio, temperature, time and particle size. The maximum yields by dried mass from the tea fibers and stalks were 1.16% and 0.92%, respectively.

Author Keywords: Author Keywords: Caffeine; Tea fiber; Tea stalk; Extraction

Corresponding author. Tel.: +90-312-231-74-00; fax: +90-312-230-84-34

Utilization of natural antioxidants: Green tea extract and Thymbra spicata oil in Turkish dry-fermented sausage

Hüseyin Bozkurt^,
Department of Food Engineering, Faculty of Engineering, University of Gaziantep, 27310 Gaziantep, Turkey
Received 4 June 2005;  revised 25 November 2005;  accepted 6 January 2006.  Available online 28 February 2006.

Abstract

Effect of natural (green tea extract, Thymbra spicata oil) and synthetic antioxidants (buthylatedhydroxytoluene, BHT) on the safety (biogenic amine and TBARS values) and quality (pH, colour and sensory attributes) of sucuk (Turkish dry-fermented sausage) were investigated during the ripening periods. Addition of antioxidants decreased (P < 0.05) the TBARS values. It was found that natural antioxidants decreased TBARS formation more than BHT. Antioxidants reduced (P < 0.05) putrescine formation in the following order: green tea extract > green tea extract–T. spicata oil > T. spicata oil > BHT, and their mean values were 70.45, 76.05, 83.13, and 95.97 mg/kg, respectively. The highest tyramine concentration was observed in control sucuk prepared without any antioxidants, while the lowest was in the recipe with green tea extract as their mean values were about 99.42 and 64.31 mg/kg, respectively. The pH, L, b, and overall sensory quality were not significantly different (P > 0.05) with the addition of green tea extract, T. spicata oil, green tea extract–T. spicata oil. These results indicated that the most effective antioxidant was found to be green tea extract. This study pointed out that natural antioxidants were more effective than synthetic antioxidants, so they could be easily utilized in sucuk to enhance quality and provide safer products.

Keywords: Green tea extract; Thymbra spicata; Natural antioxidants; Sucuk; Biogenic amines
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