Aysel Bayhan Öktem

Screening of quinolone antibiotic residues in chicken meat and beef sold in the markets of Ankara, Turkey

This study aimed to find the effects of quinolone antibiotics in chicken and beef used in Ankara, Turkey. Total number of 127 chicken and 104 beef meat samples were collected randomly from local markets for analysis. Extraction and determination of quinolones were made by ELISA procedure. One hundred eighteen of 231 (51.1%) examined chicken meat and beef samples were found to contain quinolone antibiotic residue. Among the chicken meat and beef samples, 58 (45.7%) of chicken meat samples and 60 (57.7%) of beef meat samples were positive for quinolones, respectively. The mean levels (±SE) of quinolones were found to be 30.81 ± 0.45 µg/kg and 6.64 ± 1.11 µg/kg in chicken and beef samples, respectively. This study indicated that some chicken and beef meat sold in Ankara contains residues of quinolone antibiotics.

Antimicrobial and antibiofilm effects of selected food preservatives against Salmonellaspp. isolated from chicken samples

Salmonella spp. are widespread foodborne pathogens that contaminate egg and poultry meats. Attachment, colonization, as well as biofilm formation capacity of Salmonella spp. on food and contact surfaces of food may cause continuous contamination. Biofilm may play a crucial role in the survival of salmonellae under unfavorable environmental conditions, such as in animal slaughterhouses and processing plants. This could serve as a reservoir compromising food safety and human health. Addition of antimicrobial preservatives extends shelf lives of food products, but even when products are supplemented with adequate amounts of preservatives, it is not always possible to inhibit the microorganisms in a biofilm community. In this study, our aims were i) to determine the minimum inhibitory concentrations (MIC) and minimum biofilm inhibitory concentrations (MBIC) of selected preservatives against planktonic and biofilm forms of Salmonella spp. isolated from chicken samples and Salmonella Typhimurium SL1344 standard strain, ii) to show the differences in the susceptibility patterns of same strains versus the planktonic and biofilm forms to the same preservative agent, and iii) to determine and compare antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. For this purpose, Salmonella Typhimurium SL1344 standard strain and 4 Salmonella spp. strains isolated from chicken samples were used. Investigation of antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. was done according to Clinical and Laboratory Standards Institute M100-S18 guidelines and BioTimer assay, respectively. As preservative agents, pure ciprofloxacin, sodium nitrite, potassium sorbate, sodium benzoate, methyl paraben, and propyl paraben were selected. As a result, it was determined that MBIC values are greater than the MIC values of the preservatives. This result verified the resistance seen in a biofilm community to food preservatives and highlighted this subject, not to be ignored in food applications.

The Investigation of Benzoic Acid Amounts in Some Foodstuffs Consumed in Ankara Region

Benzoic acid and its salts are commonly used as a preservatives in food products. Excess amounts of benzoic acid can be harmful to human health. Therefore, the determination of benzoic acid is important in routine analysis of foods. The aim of this study was to determine amounts of benzoic acids in some foodstuffs and to evaluate whether these amounts were within the Turkish Food Codex (TFC) values or not. For this purpose, total number of 80 samples consisting of 20 ketchup (A, B firms), 20 sauce (C, D firms) and 40 jam samples (E, F, G, H, I, J, K firms) were collected from supermarkets, Ankara Region. In this research, spectrophotometric method was used for the quantitative determination of benzoic acid in ketchup, sauce and jam samples. Mean amounts (± S.E) of benzoic acidin ketchup samples of A and B firm were found as 152.32±18.41 and 1008.21±30.74 mg/kg, respectively. Mean amounts (± S.E) of benzoic acidin sauce samples of C and D firm were determined as 990.85±26.00 and 1148.19±43.62 mg/kg, respectively. Also, mean amounts (± S.E) of benzoic acidwere found as 435.27±26.07 mg/kg in 8 jam samples of E firm. Our data revealed that while mean amounts of benzoic acid of A and C firms were found within TFC values, benzoic acid amounts of B and D firms samples were higher than the TFC values. Furthermore, some jam samples of firm E was not found appropriate to TFC.