National Food Reference Laboratory

Ankara, Turkey

National Food Reference Laboratory

Ankara, Turkey
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Koluman A.,National Food Reference Laboratory | Dikici A.,Tunceli University
Critical Reviews in Microbiology | Year: 2013

Emerging foodborne pathogens are challenging subjects of food microbiology with their antibiotic resistance and their impact on public health. Campylobacter jejuni, Salmonella spp. and Verotoxigenic Escherichia coli (VTEC) are significant emerging food pathogens, globally. The decrease in supply and increase in demand lead developed countries to produce animal products with a higher efficiency. The massive production has caused the increase of the significant foodborne diseases. The strict control of food starting from farm to fork has been held by different regulations. Official measures have been applied to combat these pathogens. In 2005 EU declared that, an EU-wide ban on the use of antibiotics as growth promoters in animal feed would be applied on 1 January 2006. The ban is the final step in the phasing out of antibiotics used for non-medical purposes. It is a part of the Commission's strategy to tackle the emergence of bacteria and other microbes resistant to antibiotics, due to their overexploitation or misuse. As the awareness raises more countries banned application of antibiotics as growth promoter, but the resistance of the emerging foodborne pathogens do not represent decrease. Currently, the main concern of food safety is counter measures against resistant bugs. © 2013 Informa Healthcare USA, Inc.

Korkmaz A.S.,Ankara University | Cakirogullari G.C.,National Food Reference Laboratory
Journal of Animal and Veterinary Advances | Year: 2011

This study was conducted to investigate the effects of dietary dried baker's yeast on growth performance, feed utilization and feed ingredients digestibility of koi carp (Cyprinus carpio L., 1758) fingerlings. In the experiment, a total of 270 koi carp fingerlings were equally divided into six groups of 45 (three replicates of 15 koi carp fingerlings each). Six levels (0,10, 20, 30, 40 and 50%) of Dried Baker's Yeast (DBY) were included in isonitrogenous and isocaloric diets. The experimental period lasted 2 months (4 fortnight period). At the end of the experiment, there were no significant differences among the groups of 0, 10, 20, 30% in Body Weight (BW), Feed Intake (FI), Protein Intake (PI), Feed Conversion Ratio (FCR) and apparent digestibility (p>0.05). The inclusion of DBY at the level of 40% to the diets reduced Weight Gain (WG), FCR, Specific Growth Rate (SGR), Protein Efficiency Ratio (PER) and apparent digestibility (p<0.05). The highest dry matter, protein, fat, fiber, ash, nitrogen free extract and organic matter digestibility coefficients were observed in fish fed diet T (control diet 0% dry yeast replacement) which were significantly higher than those observed for the other diets (p<0.05). It is concluded that DBY can be used up to 30% in the diets of koi carp fingerlings without adverse effects on the measured parameters. © Medwell Journals, 2011.

Cetinkaya M.,National Food Reference Laboratory | Baydan E.,Ankara University
Interdisciplinary Toxicology | Year: 2010

A range of pesticides is widely used in pest management and the chances of exposure to multiple organophosphorus (OP) compounds simultaneously are high, especially from dietary and other sources. Although health hazards of individual OP insecticides have been relatively well characterized, there is lesser information on the interactive toxicity of multiple OP insecticides. The aim of this study is to elicit the possible interactions in case combined exposure of an OP pesticide chlorpyrifos (CPF) and a plant growth regulator ethephon (ETF) which are used worldwide. The ileum segments of 3 months old Wistar Albino male rats were used in isolated organ bath containing Tyrode solution. ETF and CPF were incubated (10-7 M concentration) separately or in combination with each other to ileum and their effects on acetylcholine-induced contractions were studied. The data obtained from this study show that, single and combined exposure to the agents caused agonistic interactions with regard to potency of ACh whereas they caused a decrease on Emax value of ACh. These findings suggest that exposure to these agents which have direct and indirect cholinergic effects, may cause developing clinical responses with small doses and earlier but the extent of toxicity will be lower. © 2009 Slovak Toxicology Society SETOX.

Krs S.,National Food Reference Laboratory | Velioglu Y.S.,Ankara University
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2015

The effects of different wash times (2 and 5 min) with tap and ozonated water on the removal of nine pesticides from olives and the transfer ratios of these pesticides during olive oil production were determined. The reliability of the analytical methods was also tested. The applied methods of analysis were found to be suitable based on linearity, trueness, repeatability, selectivity and limit of quantification all the pesticides tested. All tap and ozonated water wash cycles removed a significant quantity of the pesticides from the olives, with a few exceptions. Generally, extending the wash time increased the pesticide reduction with ozonated water, but did not make significant differences with tap water. During olive oil processing, depending on the processing technique and physicochemical properties of the pesticides, eight of nine pesticides were concentrated into olive oil (processing factor > 1) with almost no significant difference between treatments. Imidacloprid did not pass into olive oil. Ozonated water wash for 5 min reduced chlorpyrifos, β-cyfluthrin, α-cypermethrin and imidacloprid contents by 38%, 50%, 55% and 61% respectively in olives. © 2015 Taylor & Francis

Cakirogullari G.C.,National Food Reference Laboratory | Secer S.,Ankara University
Chemosphere | Year: 2011

The concentrations of indicator polychlorinated biphenyls (PCBs) and organochlorine insecticides were determined in bonito (Sarda sarda L. 1758) and anchovy (Engraulis encrasicolus L. 1758) from the Black Sea, Turkey. Concentrations of total indicator PCBs ranged between <1-17.0 in bonito, and <1-17.5. ng/g fresh weight in anchovy, and total of 1,1,1-trichloro-2,2-bis-chlorophenyl-ethane and its metabolites' (DDTs) concentrations ranged between 13.4-26.3, and 2.96-19.0. ng/g fresh weight in bonito and anchovy respectively. PCB 52, p,p'-DDE and endosulfan (α+. β) were found dominant in both of the fish species. Except endosulfan, and some DDT metabolites, none of the studied organochlorine pesticides was detected in the fish samples. Concentrations of PCBs in anchovy were found higher than those in bonito, whereas DDT and endosulfan concentrations were found similar in both of the fish species. All of the fish samples had residue concentrations below the maximum residue limits (MRL) recommended by FAO/WHO Codex Alimentarius Commission. © 2011 Elsevier Ltd.

Olanca B.,National Food Reference Laboratory | Sivri Ozay D.,Hacettepe University
Journal of Cereal Science | Year: 2015

Wheat grain damaged by wheat bug (Eurygaster spp.) contains the bug salivary secretion which hydrolyses the gluten needed for the dough quality of breadmaking due to its proteolytic activity. Since the protease inhibitors are widespread throughout the plant kingdom, the possibility of using some plants, especially food and feed legumes to decrease the proteolytic activity of flours milled from bug damaged wheats was investigated. The proteolytic activity was considerably inhibited by pefabloc-SC and EDTA-Na2, suggesting that bug protease(s) included serine and metallo proteases. Extracts from cones of hops, seeds of grass pea, red kidney bean and sunflower caused reduction in the activity of bug protease(s). Effects of hop extract on electrophoretic, rheological properties of high protease activity flours milled from different bread wheat cultivars damaged by the bug were also studied. The dough development time and stability values of high protease activity flours increased considerably with hop extract at the lowest addition level (10:1, flour to hop extract ratio). The doughs supplemented with the hop extract had higher maximum resistance and lower extensibility values as compared to their controls. These results suggested that hop extract had improving effects on high protease activity flours due to the bug damage. © 2015 Elsevier Ltd.

Seyis Bilkay I.,Hacettepe University | Karakoc S.,National Food Reference Laboratory | Aksoz N.,Hacettepe University
Turkish Journal of Biology | Year: 2010

The effects of incubation time, temperature, pH, and agitation on indole-3-acetic acid and gibberellic acid production in Aspergillus niger were studied. For indole-3-acetic acid production, 6 days of incubation at 25 °C and pH 6.0 was found to be optimum. Optimum conditions for gibberellic acid production were 12 days of incubation at 30 °C and pH 5.0. Agitation increased both indole-3-acetic acid and gibberellic acid production. © TÜBİTAK.

Olanca B.,National Food Reference Laboratory | Ozay D.S.,Hacettepe University
Cereal Chemistry | Year: 2010

Suni-bug (Eurygaster spp.) enzyme was partially purified from bugdamaged wheat and used to prepare gluten hydrolysates at 3% and 5% degree of hydrolysis (DH). Functional properties of gluten and gluten hydrolysates were determined at 0.2% (w/v) protein concentration and pH 2-10. Gluten solubility after enzymatic hydrolysis increased significantly (P < 0.05) up to 89.1, 89.6, and 95.0% at pH 7, 8, and 10, respectively. Emulsion stability (ES) of gluten hydrolysates improved at neutral and alkaline pH (P < 0.05) and emulsifying capacity (EC) increased significantly (P < 0.05) except at pH 10. Foaming capacity (FC) values of gluten hydrolysates were significantly higher (P < 0.05) at pH 6, 7, 8; foam stability (FS) values of gluten hydrolysates were significantly higher (P < 0.05) at pH 6 and 7. Enzymatic modification of gluten by wheat-bug enzyme resulted in hydrolysates with higher antioxidant activity compared to gluten. Significant correlations (P < 0.001) were found between solubility and EC, ES, FC, and FS values of gluten and its hydrolysates with 3% and 5% DH. © 2010 AACC International, Inc.

Korkmaz A.,National Food Reference Laboratory | Kolankaya D.,Hacettepe University
Canadian Journal of Surgery | Year: 2013

Background: Nitric oxide (NO) seems to play an important role during renal ischemia/reperfusion (I/R) injury. We investigated whether rutin inhibits inducible nitric oxide synthase (iNOS) and reduces 3-nitrotyrosine (3-NT) formation in the kidneys of rats during I/R. Methods: Wistar albino rats were nephrectomized unilaterally and, 2 weeks later, subjected to 45 minutes of left renal pedicle occlusion followed by 3 hours of reperfusion. We intraperitoneally administered L-N6-(1-iminoethyl)lysine (L-NIL; 3 mg/kg) for 30 minutes or rutin (1 g/kg) for 60 minutes before I/R. After reperfusion, kidney samples were taken for immunohistochemical analysis of iNOS and 3-NT. We meas - ured plasma nitrite/nitrate and cyclic guanosine monophosphate (cGMP) to evaluate NO levels. Results: Ischemia/reperfusion caused plasma cGMP to increase significantly. Similarly, plasma nitrite/nitrate was elevated in the I/R group compared with the control group. Histochemical staining was positive for iNOS and 3-NT in the I/R group. Pretreatment with L-NIL or rutin significantly mitigated the elevation of plasma cGMP and nitrite/nitrate. These changes in biochemical parameters were also associated with changes in immunohistochemical appearance. Pretreatment with L-NIL or rutin significantly decreased the incidence and severity of iNOS and 3-NT formation in the kidney tissues. Conclusion: Our findings suggest that high activity of iNOS causes renal I/R injury, and that rutin exerts protective effects, probably by inhibiting iNOS. © 2013 Canadian Medical Association.

Korkmaz A.,National Food Reference Laboratory | Ahbab M.A.,Hacettepe University | Kolankaya D.,Hacettepe University | Barlas N.,Hacettepe University
Food and Chemical Toxicology | Year: 2010

The purpose of this study was to investigate whether bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) induce oxidative stress in the liver of male rats and co-administration of vitamin C can prevent any possible oxidative stress. Wistar male rats were divided into seven groups (vehicle, BPA, NP, OP, BPA+C, NP+C, OP+C). BPA, OP and NP groups (25mgkg-1day-1) were administered orally to rats three times a week for 50days. In BPA+C, NP+C, OP+C groups, vitamin C (60mgkg-1day-1) was administered along with BPA, OP and NP (25mgkg-1day-1) treatments. Aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), thiobarbituric acid-reactive substances (TBARS) were increased, glutathione (GSH) levels were decreased in treatment groups. AST, ALT, LDH and TBARS levels were increased whereas GSH levels were decreased in BPA+C, NP+C and OP+C groups compared to BPA, NP, and OP groups, respectively. Hepatic necrosis and congestion were observed in livers of rats treated. In conclusion, the present results demonstrate that BPA, NP, and OP cause oxidative damage by disturbing the balance between ROS and antioxidant defenses system in liver of male rats. Vitamin C co-administration along with BPA, NP, OP aggravates the damage in liver of male rats. © 2010 Elsevier Ltd.

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