Analysis of Multi-Mycotoxins in Commonly Consumed Spices Using the LC-MS/MS Method for Assessing Food Safety Risks.

Mycotoxins are secondary metabolites produced by certain fungal species. In this study, the aim was to investigate mycotoxins, which pose a serious health problem. For this purpose, a total of 140 spice samples (black pepper, red pepper, cumin, and turmeric) purchased from Ankara, Turkey, were analyzed for specific mycotoxins (aflatoxin B1-AFB1, aflatoxin B2-AFB2, aflatoxin G1-AFG1, aflatoxin G2-AFG2, ochratoxin A-OTA, zearalenone-ZEN) using an LC-MS/MS multi-mycotoxin method. The Staphylococcus spp. and Micrococcus spp. counts in the spice samples were also analyzed using the conventional culture method. The contamination levels of AFB1 ranged from not detected (ND) to 39.12 µg/kg; AFB2 ranged from ND to 2.10 µg/kg; AFG1 ranged from ND to 0.92 µg/kg; AFG2 ranged from ND to 3.67 µg/kg; OTA ranged from ND to 39.79 µg/kg; ZEN ranged from ND to 11.16 µg/kg. The maximum residue limit for AFB1 (5 µg/kg) determined according to the Turkish Food Codex (TFC) was exceeded in five samples of red pepper, two samples of black pepper, and one sample of turmeric. Furthermore, it was determined that three samples of red pepper and one sample of black pepper exceeded the maximum limits for total aflatoxin (10 µg/kg) and OTA (15 µg/kg) specified in the TFC.

Detection of Antibiotic Residues in Blossom Honeys from Different Regions in Turkey by LC-MS/MS Method.

In the present study, a total of 80 commercial blossom honey samples were obtained from local markets in Ankara, Turkey. These honeys were analyzed for 35 important and risky antibiotics (sulfonamide, tetracycline, macrolide, cephalosporin, aminoglycoside, quinolone, nitrofuran, chloramphenicol, and anthelmintic groups) by the LC-MS/MS multi-antibiotic method. In addition to these analyses, pH measure, moisture, and electrical conductivity were determined in these honey samples. Finally, seven out of 35 antibiotic residues investigated in the honeys were positive. The most frequently detected antibiotics in the analyzed samples were dihydrostreptomycin, streptomycin, erythromycin, sulfadimidine (sulfamethazine), and enrofloxacin as 58.75%, 22.5%, 13.75%, 10%, and 2.5%, respectively. Tetracycline and doxycycline were detected in only one sample. The pH, moisture, and electrical conductivity values of the honey samples were determined as between pH 3.78 and 5.41, 17.48 and 18.03%, and 0.25 and 0.47 mS/cm, respectively. In terms of food safety and human health, it is very important to monitor the residues of these pharmacologically active substances with analytical methods.

Investigation of Twelve Significant Mycotoxin Contamination in Nut-Based Products by the LC-MS/MS Method.

In this study, a total of 80 peanut butter, hazelnut butter, and chocolate samples were obtained from local markets in Ankara, Turkey. These foods were analyzed for twelve toxicological important mycotoxins, such as aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2); fumonisin B1 (FB1) and fumonisin B2 (FB2); ochratoxin A (OTA); sterigmatocystin (STE); deoxynivalenol (DON); zearalenone (ZON); T-2 toxin (T2); and HT-2 toxin (HT2) by the LC-MS/MS multi-mycotoxin method. In addition to this analysis, the presence of total aerobic mesophilic bacteria was investigated in the samples. The samples were analyzed microbiologically using standard procedures. Finally, the minimum and maximum levels of AFB1, AFB2, AFG1, FB2, OTA, STE, DON, ZON, T2, and HT2 in the samples were found to be 0.04-27.37 µg/kg, 0.06-6.19 µg/kg, 0.14-0.40 µg/kg, 2.73-2.93 µg/kg, 0.01-37.26 µg/kg, 0.19-2.25 µg/kg, 11.81-42.09 µg/kg, 0.03-7.57 µg/kg, 1.41-2.54 µg/kg, and 6.94-7.43 µg/kg, respectively. AFG2 and FB1 were not detected in any of the samples. The most frequently detected mycotoxins in analyzed samples were OTA (78.75%) and AFB1 (75%). In addition, total aerobic mesophilic bacteria were isolated from 53.75% of samples. Some of the tested food samples contained mycotoxins above the Turkish Food Codex maximum limit.

The Investigation of Mycotoxins and Enterobacteriaceae of Cereal-Based Baby Foods Marketed in Turkey.

In this study, a total of 85 cereal-based baby foods with or without milk (four different brands; A, B, C, and D) collected from Ankara local markets, Turkey were analyzed for mycotoxins, total aerobic mesophilic bacteria (TAMB), and Enterobacteriaceae contamination. Baby foods were analyzed for 12 toxicological important mycotoxins such as aflatoxin B1, B2, G1, and G2; fumonisin B1 and B2; ochratoxin A; sterigmatocystin (STE); deoxynivalenol (DON); zearalenone (ZON); and T-2 toxin and HT-2 toxin by LC-MS/MS multi-mycotoxin method. In addition to these mycotoxins, the presence of aflatoxin M1 (AFM1) was investigated in baby foods containing milk. The classical culture method was used for microbiological analysis. Consequently, at least one mycotoxin was detected in 69.41% of the total samples. The most frequently detected mycotoxins were STE (34.12%) and HT-2 (34.12%). However, AFM1 was not detected in any of the baby foods containing milk. Also, TAMB and Enterobacteriaceae were isolated from 30.59% and 10.59% of samples, respectively. As a result, it was determined that the mycotoxin levels in the analyzed samples were in accordance with the mycotoxin levels specified in the Turkish Food Codex.

Highly luminescent water-dispersed silicon quantum dots for fluorometric determination of oxytetracycline in milk samples.

A fluorescent probe based on silicon quantum dots (SiQDs) was developed for the selective and sensitive detection of oxytetracycline (OTC) via the inner filter effect (IFE). The water-soluble fluorescent SiQD was synthesized based on the reaction of 3-Aminopropyltriethoxysilane (APTES) and sodium citrate as precursors by the one-pot hydrothermal process. The strong fluorescence emission of quantum dots (QDs) was obtained at 440 nm when excited at 350 nm and OTC had a broad absorption band between 200 and 400 nm. The excitation spectrum of SiQDs was completely overlapped with the absorption spectrum of OTC. The light at an excitation wavelength of QDs absorbed by OTC caused a decrease in fluorescence intensity with an increase in the concentration of OTC. Under optimal conditions, the linear concentration range was 0.92-9.2 µg mL1 with a detection limit (LOD; S/N = 3) of 0.19 µg mL -1 . The proposed method was applied to the determination of OTC in milk samples and satisfactory recoveries (98.8-100.5%) with low RSD % values (0.93-2.31%) were achieved. This simple, selective, sensitive, rapid, and cheap method can be used as a promising tool for OTC analysis in food safety.

Room-temperature phosphorescence determination of melamine in dairy products using l-cysteine-capped Mn-doped zinc sulfide (ZnS) quantum dots.

A simple, sensitive, and precise room-temperature phosphorescence method was developed for the determination of melamine in dairy products using l-cysteine-capped Mn-doped zinc sulfide (ZnS) quantum dots as a probe. This method is based on the quenching of the phosphorescence signal of quantum dots by the interaction with melamine. Under optimum conditions, phosphorescence intensity was quenched by various concentrations of melamine in a linear range from 50 to 500ng/mL, with a detection limit of 5.95ng/mL in 10 mM phosphate buffer (pH 7.4). The relative standard deviation for 5 replicate measurements was 0.15%. The developed method was applied to dairy products to determine melamine concentrations; recovery values ranged from 96.3 to 104.7%.

Monosodium glutamate in chicken and beef stock cubes using high-performance liquid chromatography.

In this survey monosodium glutamate (MSG) levels in chicken and beef stock cube samples were determined. A total number of 122 stock cube samples (from brands A, B, C, D) were collected from local markets in Ankara, Turkey. High-performance liquid chromatography with diode array detection (HPLC-DAD) was used for quantitative MSG determination. Mean MSG levels (±SE) in samples of A, B, C and D brands were 14.6 ± 0.2 g kg⁻¹, 11.9 ± 0.3 g kg⁻¹, 9.7 ± 0.1 g kg⁻¹ and 7.2 ± 0.1 g kg⁻¹, respectively. Differences between mean levels of brands were significant. Also, mean levels of chicken stock cube samples were lower than in beef stock cubes. Maximum limits for MSG in stock cubes are not specified in the Turkish Food Codex (TFC). Generally the limit for MSG in foods (except some foods) is established as 10 g kg⁻¹ (individually or in combination).

Antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. 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.

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.