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    ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF WHITE, GREEN AND BLACK TEA EXTRACTS
    (Akademiai Kiado Zrt, 2013) Orak, H. H.; Yagar, H.; Isbilir, S. S.; Demirci, A. S.; Gumus, T.
    In the present study, the antioxidant and antimicrobial activities of three tea (Camellia sinensis) types (white tea WT, green tea - GT, and black tea - BT) were compared and the relationships between total phenolic, tannin and flavonoid contents were determined. Regardless of the assays used, the highest total phenolic content (313.3 +/- 1.41 mu g GAE/mg extract), total flavonoid (16.98 +/- 0.27 mu g QE/mg extract) and total tannin content (266.79 +/- 2.59 mu g TAE/mg extract) were determined in green tea extract, which also demonstrated the highest antioxidant capacity. Black tea extract showed the lowest phenolic content and antioxidant capacity. The EC50 value of DPPH scavenging activity was in the order of: ascorbic acid >GT>BHA>WT>BT>BHT. While the tea extracts exhibited antibacterial activity against Staphylococcus aureus, no inhibitory effects were observed against Escherichia coli and Salmonella enteritidis. All extracts exhibited antifungal activity against two aflatoxigenic moulds Aspergillus parasiticus NRRL 2999 and NRRL 465. The antibacterial activity of tea extracts decreased in the following order: GT>WT>BT DPPH scavenging activity strongly correlated with total phenolic content, reducing power, antimicrobial activity against S. aureus, A. parasiticus NRRL 2999, A. parasiticus NRRL 465 (P<0.05). These data suggest that green tea extract is more effective than white and black tea extracts as a potential source of natural antioxidants.
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    Microbiological Quality of Cream-Cakes Sold in Tekirdag Province
    (Univ Namik Kemal, 2005) Gumus, T.; Daglioglu, O.; Konyali, A. M.
    This study was aimed to determine the microbiological qualities of totally 120 cream cakes including chocolate and fruit type, purchased from 30 randomly selected pastry shops in Tekirdag province. Based on the Turkish Food Codex Microbiological Criterias Communique; 59, 50, 16 and 53 out of 60 chocolate cake samples tested were found to be potentially hazardous/unacceptible respectively for total mesophilic aerobic bacteria (98.3% of the total > 10(5) cfu/g), coliform bacteria (83.3% of the total > 10(2) cfu/g), Staphylococcus aureus (26.6% of the total > 10(2) cfu/g) and yeast and mould (88.3% of the total > 10(3) cfu/g). On the other hand, 60, 56, 19 and 55 out of 60 fruit cake samples tested were found to be potentially hazardous/unacceptible respectively for total mesophilic aerobic bacteria (100 % > 10(5) cfu/g), coliform bacteria (93.3% of the total > 10(2) cfu/g), Staphylococcus aureus (31.6% of the total > 10(2) cfu/g) and yeast and mould (91.6% of the total > 10(3) cfu/g). Salmonella were not detected in any of the chocolate and fruit cake samples. Obtained results showed that the microbiological qualities of cakes were poor due to poor hygiene and poor food handling practices in pastry shops.