Arzu Mehmetoglu

Dr. Arzu Mehmetoglu

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2012 in Journal of Dairy Science
Verified
Journal Article
Closed access
AMArzu Mehmetoglu
Arzu Mehmetoglu
SKS. Kusakli
S. Kusakli
MVMaryna van de Venter
Maryna van de Venter
The aim of this research was to assess the amounts of polysaccharide and surfactin produced by Bacillus subtilis ATCC 6633 in rehydrated whey powder (RWP) as the growth medium. One-day-old cultures of B. subtilis (similar to 4.6 log cfu/mL) were inoculated into 100 mL of 10, 15, or 20% (wt/vol) RWP and incubated at 30 degrees C for 72 h. To analyze the effects of lactose and protein on polysaccharide and surfactin production, 6 RWP solutions containing different levels of lactose and protein were also used as media. The number of vegetative cells and spores, pH, viscosity; and the concentration of lactose were determined at 0, 24, 48, or 72 h of fermentation. The levels of polysaccharide and surfactin produced after 72 h of fermentation were measured using HPLC and the phenol-sulfuric acid method, respectively. During 72 h of fermentation, B. subtilis populations increased from 4.6 to 10.54, 9.82, and 9.67 log(10) cfu/mL in 10, 15, and 20% RWP, respectively. The number of B. subtilis spores in 10% RWP increased from 3.91 to 4.72 log(10) cfu/mL after 48 and 72 h of fermentation, respectively. The increased level of lactose or protein in RWP did not significantly change the vegetative growth. After 72 h of fermentation, the pH of RWP decreased from 5.70 to 4.99 with a slight increase in viscosity. Polysaccharide levels in 10, 15, and 20% RWP after fermentation were 513.6; 613.5; and 768.3 mg/L; respectively, with B. subtilis producing 0.18 to 0.29 g/L of surfactin after 72 h of fermentation. The polysaccharide or surfactin production was not changed significantly by addition of protein or lactose to RWP. These results indicate that RWP is a good fermentation substrate for surfactin and polysaccharide production.

1 March 2013 in Food Additives & Contaminants: Part B
Verified
Journal Article
Closed access
RCRuziye Cakir
Ruziye Cakir
AMArzu Mehmetoglu
Arzu Mehmetoglu
Sorbic acid (SA) and benzoic acid (BA) were determined in yoghurt, tomato and pepper paste, fruit juices, chocolates, soups and chips in Turkey by using high-pressure liquid chromatography (HPLC). Levels were compared with Turkish Food Codex limits. SA was detected only in 2 of 21 yoghurt samples, contrary to BA, which was found in all yoghurt samples but one, ranging from 10.5 to 159.9 mg/kg. Both SA and BA were detected also in 3 and 6 of 23 paste samples in a range of 18.1-526.4 and 21.7-1933.5 mg/kg, respectively. Only 1 of 23 fruit juices contained BA. SA was not detected in any chips, fruit juice, soup, or chocolate sample. Although 16.51% of the samples was not compliant with the Turkish Food Codex limits, estimated daily intake of BA or SA was below the acceptable daily intake.

1 March 2018 in Food Science and Technology
Verified
Journal Article
Open access
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AMArzu Mehmetoglu
Arzu Mehmetoglu
Consumer food safety concerns are continually increasing in Turkey, with consumer demand for safer foods becoming an important challenge for the industry. Most traditional foods in Turkey are produced under different requirements, and food safety risk management and risk assessment are conducted primarily by the government. Based on risk assessment, safety regulations and standards for traditional foods (e.g. Turkish white cheese, doner, helva) have been established. In this paper, safety concerns surrounding the commercialization of traditional Turkish foods and related studies to identify and minimize potential hazards are discussed along with pathogen contamination in raw meat balls and aflatoxin in helva and white cheese. Based on this review, additional national risk analysis experts and related databases are urgently needed. In addition, the manufacturing processes for traditional foods need to be standardized and harmonized with international standards, such as CODEX.

1 November 2011 in Poultry Science
Verified
Journal Article
Open access
AMArzu Mehmetoglu
Arzu Mehmetoglu
The present study was designed to determine the inhibitory effect of scallop-shell powder (SSP) on Listeria monocytogenes and Salmonella enteritidis on chicken wings. Chicken wings artificially inoculated with L. monocytogenes (8.3 log(10) cfu/g) or S. enteritidis (8.8 log(10) cfu/g) were immersed in distilled water (0.10 or 0.50% wt/vol) of SSP slurries for 10 or 30 min, respectively. The amount of L. monocytogenes, S. enteritidis, mesophilic aerobic bacteria (MAB), and yeast or mold was determined for the chicken wings at d 0 or 7 of storage at 4°C. Results indicated that 0.5% SSP decreased the amount of L. monocytogenes and S. enteritidis on chicken wings by 3.7 and 5.0 log(10) cfu/g, respectively. The growth of L. monocytogenes, S. enteritidis, MAB, and yeast or mold was inhibited by SSP during the 7-d refrigerated storage. Color and odor of chicken wings were not significantly changed by SSP treatment (P > 0.05).


5 August 2020 in International Journal of Food Science and Technology
Verified
Journal Article
Closed access
PDF file
AMArzu Mehmetoglu
Arzu Mehmetoglu
Elif SezerElif Sezer
Elif Sezer
SESümeyye Erol
Sümeyye Erol