Browsing by Author "Tosun H."
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Item A Study on the Effects of Chilling on the Microbiological Quality of Poultry Carcasses and Surface Decontamination with Lactic Acid; [Soǧutma İşleminin Kanatli Karkasinin Mikrobiyal Kalitesine Etkisi ile Laktik Asitle Yüzey Dekontaminasyonu Üzerine Araştirmalar](2000) Tosun H.; Tamer A.Ü.Effects of immersion chilling on the microbiological quality of poultry carcasses and cross contamination of Salmonella were studied. Levels of aerobic mezophilic bacteria, coliform, Escherichia coli and the incidence of Salmonella were determined prechill and postchill. The level of coliform and E. coli were reduced by immersion chilling (P<0.01). The reduction of aerobic mezophilic bacteria was not significantly significant (P>0.05) but there was an increase in Salmonella incidence in carcasses exiting the immersion chiller indicating that this may be the point of most significant cross contamination in broiler processing plants. Experiments on microbial decontamination of poultry carcasses with lactic acid were performed. The microbial levels of poultry carcasses were reduced significantly by lactic acid treatment (P<0.05). Treatment with lactic acid (1%) resulted in a 1.259, 1.685 and 2.023 logaritmic unit reduction in colony forming units of aerobic mezophilic bacteria, coliform and E. coli. Other treatments with lactic add (3%) resulted in a 2.502, 3.876 and 3.820 logaritmic unit reduction in colony forming units of aerobic mezophilic bacteria, coliform and E. coli compared with the control samples. Salmonella was not isolated from decontaminated broiler carcasses with 1% and 3% of lactic acid solutions. Lactic acid can be used eliminate Salmonella from poultry carcasses and extend the shelf life of processed broilers. However undesirable organoleptic characteristics may occur when it is used at high concentrations.Item The effect of acid adaptation conditions on heat resistance of Escherichia coli O157: H7(2005) Tosun H.; Gönül Ş.A.The objective of this study was to determine the effect of acid adaptation conditions on heat resistance of E. coli O157: H7 932. E. coli O157: H7 was adapted to acid by exposing the cells to pH 4.5 (2h), pH 5.0 (1h), and pH 5.5 (1 h) in tryptic soy broth. D and z values of the acid adapted and control cultures at 54°C, 56°C, and 58°C were determined in E buffer. The heat resistance of E. coli O157: H7 increased significantly (p<0.05) after acid adaptation at pH 4.5 or pH 5.0. E. coli O157: H7 adapted to acid at pH 4.5 for 2 h had the highest D values at all temperatures tested (20.3-10.7-3.3 min) while D values of culture adapted to acid at pH 5.0 for 1 h were 18.2, 7.9, and 2.6 min at 54°C, 56°C and 58°C, respectively. Heat resistance of culture adapted to acid at pH 5.5 for 1 h and the control culture was not significantly different (P<0.05). Culture adapted to acid at pH 4.5 had the highest z value (5.10°C), whereas control culture had the lowest z value (4.33°C). This study showed that the magnitude of heat tolerance changed with the adaptation pH and at low adaptation pH, E. coli O157: H7 showed maximum heat resistance. Acid adaptation at pH 4.5 or 5.0 provides E. coli O157: H7 with cross-protection against heat treatments, and that this factor must be considered to estimate this pathogen's thermal tolerance accurately.Item Acid adaptation effect on survival of Escherichia coli O157:H7 in fermented milk products(2007) Tosun H.; Seçkin A.K.; Aktuǧ Gönöl Ş.The growth and survival of acid-adapted and nonadapted Escherichia coli O157:H7 were determined in strained, set-type, and synbiotic yoghurt and kefir. Acid-adapted or nonadapted E. coli O157:H7 were inoculated into the synbiotic and set-type yoghurt before and after the fermentation process. Survival of the inoculated E. coli O157:H7 in these products was examined during storage at 4 °C. Acid adaptation enhanced the survival of E. coli O157:H7 in kefir and strained yoghurt. Acid adaptation also enhanced the survival of E. coli O157:H7 in set-type yoghurt, which was inoculated after the fermentation process; however, acid-adapted cell inoculation before fermentation did not enhance survival. These observations support the theory that acid adaptation is an important survival mechanism enabling E. coli O157: H7 to persist in fermented dairy products. © TÜBİTAK.Item Effect of various chemical decontamination treatments on natural microflora and sensory attributes of chicken liver(2010) Tosun H.; Ergönül B.; Obuz E.This study was undertaken to determine the effect of different chemical decontamination methods on the microbiological and sensory attributes of chicken liver during refrigerated storage (+4 ± 1 °C). Chicken liver samples were dipped into sterilized water (1 min), lactic acid (1.5%, 1 min or 5 min), acetic acid (1.5 %, 1 min or 5 min), trisodium phosphate (15 %, 15 min or 20 min) or were not treated (control). Microbiological analyses were carried out at 0, 2 and 4 days of storage. Also, sensorial attributes were evaluated by panelists. As result of the study, decontamination with acetic acid, lactic acid or trisodium phosphate could not substantially improve the microbiological quality of chicken liver during refrigerated storage. On the other hand, sensorial attributes of the samples were adversely affected by treatments except the treatments with acetic acid. © M. & H. Schaper GmbH & Co.Item Effects of prebiotics (inulin and fructooligosaccharide) on quality attributes of dried yoghurt (kurut)(2010) Seçkin A.K.; Ergönül B.; Tosun H.; Ergönül P.G.Chemical and microbiological attributes of prebiotic kurut were investigated. Prebiotic kurut was obtained by adding inulin and fructooligosaccharide into strained yoghurt. Chemical attributes and microbiological analysis like total mesophylic aerobic bacteria, yeast and mold, lactic acid bacteria and total coliform bacteria counts were determined. Textural analyses of kuruts were also performed by texture analyzer. It was determined that using different amounts and types of polysaccharides in formulation did not affect the pH and aw values, salt, ash, protein, water, fat and cholesterol contents and acidity values of the samples (p > 0.05). Also, firmness values, total mesophylic aerobic bacteria, lactic acid bacteria and coliform counts of kurut samples were not affected by using added polysaccharides in formulation (p>0.05), whereas total yeast and mould counts of kuruts were affected by the formulation (p<0.05).Item Several quality attributes of beef and turkey meat doner kebabs produced by traditional or continuous process(Springer, 2012) Ergönül B.; Tosun H.; Obuz E.; Kundakçı A.The chemical, microbiological and sensory properties of doners produced by traditional or continuous processes were investigated. The production method (traditional or continuous) did not affect microbiological quality (p<0.05). Doners produced by traditional process had generally better sensory properties than those produced by continuous process. Continuous process produced turkey meat doners with lesser fat content (p<0.05), higher moisture content (p<0.05). Even though, doners produced by the traditional process were given higher ratings by the sensory panel than those produced by the continuous process, the difference might not have any practical importance. Given the higher production capacity, continuous process is expected to replace traditional process in the years to come. © Association of Food Scientists & Technologists (India) 2012.Item Occurence of total aflatoxin, ochratoxin a and fumonisin in some organic foods(2013) Kaya S.B.; Tosun H.In organic food production the use of synthetic antifungal agents is prohibited for this reason organic food may be more susceptible to fungal contamination. In this study, a total of 235 samples of organic foods (maize flour, wheat flour, barley flour, rye flour, raisin, fig, prune, dried fruits and molasses) produced in Turkey were analyzed for possible contamination with aflatoxin, ochratoxin A (OTA) and fumonisin. A total of 159 organic food samples were analyzed for aflatoxin, in 14.46 % of these samples aflatoxin was detected. The concentrations of aflatoxin in cereals, dried fruits and molasses ranged from 0 to 42.73 μg/kg, 0 to 10.47 μg/kg and 0 to 29.3 μg/kg respectively. A total of 221 samples were analyzed for ochratoxin A and 43.43 % of these samples were contaminated with OTA. The concentrations of ochratoxin A in cereals, dried fruits and molasses ranged from 0 to 18.11 μg/kg, 0 to 34.35 μg/kg and 0 to 25.24 μg/kg respectively. A total of 225 samples were analyzed for fumonisin, in 24.88 % of the samples fumonisin was detected. The concentrations of fumonisin in cereals, dried fruits and molasses ranged from 0 to 1684 μg/kg, 0 to 1816 μg/kg and 0 to 1714 μg/kg. respectively. The results showed that organic foods maybe contaminated mycotoxins and effective organic antifungal agents must be used.Item Occurrence of aflatoxin M1 in organic dairy products(Wageningen Academic Publishers, 2013) Tosun H.; Ayyildiz T.Organic foods are perceived more nutritious, safer and healthier than conventional foods by consumers. Organic foods contain lower levels of pesticides and nitrates than conventional produce. However, studies on mycotoxin content of organic foods are limited. The aim of this study was to investigate aflatoxin M1 (AFM1) levels of organic milk and organic milk products produced in Turkey. In this study, 188 organic dairy products consisting of organic ultra-high temperature (UHT) milk (39 samples), organic yogurt (26 samples), organic cheese (91 samples) and organic butter (32 samples) were examined for AFM1. ELISA was used for analysis of the samples. Samples were collected from organic markets in Turkey. AFM1 was detected in 39 (100%) organic UHT milk samples (mean: 65 ng/kg; range: 57-78 ng/kg), 39 (43%) organic cheese samples (mean: 137 ng/kg; range: 9-487 ng/kg) and 26 (100%) organic yogurt samples (mean: 238; range: 125-269 ng/kg). AFM1 contamination was not detected in organic butter samples. AFM1 levels of 7 (8%) organic cheese samples, 39 (100%) organic UHT milk samples and 26 (100%) organic yogurt samples were above the maximum tolerable limit of the Turkish Food Codex. The results indicated that the level of AFM1 in organic dairy products, especially organic yogurt and organic UHT milk, could be a potential risk for consumers.Item Determination of aflatoxin B1 levels in organic spices and herbs(2013) Tosun H.; Arslan R.Organically produced spices and herbs were analyzed for determination of aflatoxin B1 (AFB1) by ELISA using immunoaffinity column. For this purpose 93 organic spices and 37 organic herbs were randomly selected from organic markets and organic shops in Turkey. AFB1 was detected in 58 organic spice and 32 organic herb samples. Among organic spice samples, the maximum value was detected in cinnamon sample (53 g/kg). AFB1 was not detected in thyme samples. AFB1 levels of 41 organic spice samples were above the EU regulatory limit (5 g/kg). Among organic herb samples the highest concentration of AFB1 (52.5 g/kg) was detected in a rosehip sample. AFB1 levels of 21 organic herb samples were above the regulatory limits of the European Union. These results showed that more stringent measures must be taken for the prevention of mold contamination in the production of organic spices and herbs. © 2013 Halil Tosun and Recep Arslan.Item Ochratoxin A in grape pekmez (grape molasses) consumed in Turkey(2014) Tosun H.; Yildiz H.; Obuz E.; Seçkin A.K.In this study, ochratoxin A (OTA) in 55 home-made, 20 commercial and 7 organic grape pekmez (grape molasses) produced in Turkey was investigated. OTA was detected in 73% of home-made pekmez samples, in 35% of commercial pekmez samples and in 71% of organic pekmez samples. Eleven per cent of the samples had OTA levels higher than 10 μg/l. The highest OTA level (31 μg/l) was detected in organic pekmez. The maximum OTA levels were 15 μg/l and 12 μg/l in home-made and commercial pekmez samples, respectively. Mean OTA levels were 3.5 μg/l, 1.4 μg/l and 9.2 μg/l in home-made, commercial and organic pekmez samples, respectively. Organic pekmez samples and home-made pekmez samples had higher OTA contamination than commercial pekmez samples. Results confirm OTA contamination in grape pekmez samples, indicating that the OTA level in grape pekmez could be a potential risk for consumers. © 2013 © 2013 Taylor & Francis.Item Aflatoxin M1 in Tarhana chips(Taylor and Francis Ltd., 2014) Özçam M.; Obuz E.; Tosun H.Tarhana chips are a popular traditional fermented food consumed widely in the Kahramanmaraş region of Turkey. Tarhana chips are different from many other types of fermented food in that they are produced in the form of tortilla chips. Cereal and yoghurt are the main ingredients in Tarhana chips. Aflatoxin M1 (AFM1) levels in dairy and dairy-based products are of concern for human health. To investigate AFM1 contamination, a total of 40 samples were collected from Kahramanmaraş region and AFM1 levels were determined by competitive enzyme-linked immunosorbent assay (ELISA). Furthermore, physicochemical characteristics of Tarhana chips were investigated and compared with classic fried chips in terms of nutritional value. Based on data obtained from enzyme-linked immunosorbent assay, 21 (52.5%) out of 40 samples contained AFM1 in the range 0.5-36.6 ng/kg, so AFM1 levels of all samples were below the legal limit. © 2014 ©2014 Taylor & Francis.Item Occurrence of aflatoxins (B1, B2, G1, G2) in herbal tea consumed in Turkey(Birkhauser Verlag AG, 2016) Tosun H.; Ergönül P.G.; Üçok E.F.Aflatoxin contents in 12 types of herbal teas were determined by high performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. Forty eight samples were collected from four local herbal shops in Manisa, Turkey. Of the 48 samples analyzed, 43 were aflatoxin positive. The highest concentration of aflatoxin (34.18 µg/kg) was determined in a sample of camomile tea. The occurrence of AFB1, B2, G1 and G2 was found in samples at levels of 54, 29, 71 and 46 %, respectively. Aflatoxin B1, B2, G1 and G2 contamination levels varied from 0 to 14.2, 0 to 12.4, 0 to 13.5 and 0 to 28.7 µg/kg, respectively. Aflatoxin was not detected in five samples consisting of linseed, lime and fennel tea. © 2016, Bundesamt für Verbraucherschutz und Lebensmittelsicherheit (BVL).Item Real-time PCR is a potential tool to determine the origin of milk used in cheese production(Academic Press, 2017) Kemal Seçkin A.; Yilmaz B.; Tosun H.Traceability of foods has become very important problem respect to food quality and typicalness of foods. Cheeses' milk origin cannot be identified by the consumer and they are sold at different prices under various product names. Recently, this has caused the problem of 'adulteration'. The aim of this study is to determine the amount and origin of milk used in cheese production by using real-time PCR which has been used for identification of animal species in dairy products. In this study, 90 different cheeses offered for sale in Turkey of 30 brands from various sources such as cow, sheep and goat have been studied. At the end of the study, only 36.67% of samples were determined to be produced from 100% cow milk. In the remaining 13.33%, a mixture of goat and sheep milk have been found. Only one sample of sheep cheese was produced from 100% sheep milk. In goat cheese samples, 16.67% of cheese was produced from 100% sheep milk and the origin of only 10% was identified as 100% cow milk. No linear relationship could be determined between chemical composition, fatty acids ratios and amount and origin of cheeses (P < 0.05). © 2016 Elsevier Ltd