Evaluation of Sodium Benzoate and Potassium Sorbate Preservative Concentrations in Different Sauce Samples in Urmia, Iran.

Sodium benzoate and potassium sorbate are relatively common preservatives used in a wide range of foods including flavoring products like sauces. The potential health risks arising from these preservatives along with the high-consumption rate of these flavoring products worldwide highlight the importance of the quality and safety assurance of these products. So, this study aimed to evaluate the concentrations of these two common preservatives (i.e., sodium benzoate and potassium sorbate) in different sauce samples, including mayonnaise, salad dressings, Caesar sauce, Italian dressing, Ranch dressing, French dressing, using high-performance liquid chromatography (HPLC) and to compare them with the acceptable level of Codex standard. For this purpose, 49 samples, including three to five samples of each type of different brands of sauce samples, were randomly collected from supermarkets in Urmia, Iran. Based on the results, the mean concentrations ± standard deviation of sodium benzoate and potassium sorbate in the collected samples were found to be 249.9 ± 157 and 158.0 ± 131 ppm, respectively, which were lower than the general standard of the Codex Alimentarius and the European legislation. Due to the importance of hazardous side effects of these preservatives for consumers, regular and accurate evaluation of these preservatives in sauces as highly consumed food products is still recommended for consumer safety.

Susceptibility of Salmonella serotypes isolated from meat and meat contact surfaces to thermal, acidic, and alkaline treatments and disinfectants.

The present study was conducted to evaluate the response of 29 Salmonella isolates to exposure to thermal (60°C for 2 min), acidic (pH 2.9 for 30 min), and alkaline (pH 11 for 60 min) treatments and investigate the susceptibility of the isolates and their biofilms to disinfectants. The reductions of Salmonella isolates populations subjected to each treatment were analyzed according to their isolation source, serotype, antibiotic resistance pattern, and biofilm formation ability. Median reductions for all of Salmonella isolates populations after thermal, acidic, and alkaline treatments were 1.8, 2.1, and 0.7 log CFU/ml, respectively. The isolates behavior under stress conditions were not related to their isolation source, serotype, or biofilm formation ability. The median reduction after alkaline treatment in non-MDR (multidrug- resistant) isolates populations was significantly (p < .05) higher than MDR isolates. The median reduction in biofilms of moderate biofilm producers by disinfectants was significantly (p < .05) higher than that of strong biofilm producers. In conclusion, Salmonella isolates showed the highest susceptibility to acidic treatment and MDR isolates were more resistant to alkaline treatment than non-MDR ones. The current study also revealed that the strong biofilm producer isolates were more resistant to disinfectants than moderate biofilm producers. This study facilitated the understanding of the relationship between Salmonella characteristics (isolation source, serotype, antibiotic resistance pattern, and biofilm formation ability) and its susceptibility to thermal, acidic, and alkaline treatments and disinfectants. The findings are helpful for the prevention and control of Salmonella.

Antibacterial interactions of pulegone and 1,8-cineole with monolaurin ornisin against Staphylococcus aureus.

The aim of this study was to investigate the antibacterial interactions of pulegone and 1,8-cineole with monolaurin ornisin against Staphylococcus aureus. The individual and combined antibacterial activities of the compounds were evaluated using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), fractional inhibitory concentration index (FICi), and time-kill methods. Furthermore, the mechanism of the antibacterial action of the compounds was tested by measuring the release of cell constituents. The MIC values of pulegone, 1,8-cineole, nisin, and monolaurin were 5.85 µl/ml, 23.43 µl/ml, 6.25 µg/ml, and 0.031 mg/ml, respectively. A synergistic antibacterial activity (FICi = 0.5) was found between 1,8-cineole and nisin. The time-kill assay showed that the populations of S. aureus exposed to 1,8-cineole, nisin, and their combination were decreased by 5.9, 5.3, and 7.1 log CFU (colony-forming units)/mL, respectively. The combination of 1,8-cineole and nisin also induced the highest release of cell constituents. It was concluded that the combination of 1,8-cineole and nisin could be considered as a novel and promising combination which may reduce the required dose of each antibacterial compound.

Antibiotic resistance and biofilm formation ability of Salmonella serotypes isolated from beef, mutton, and meat contact surfaces at retail.

In this study, Salmonella isolates recovered from meat (beef and mutton) and meat contact surfaces at retail were investigated to determine their serotype, antibiotic resistance, and biofilm formation ability. Salmonella was found in 29 (24.17%) samples out of 120 samples including 14/50 (28%) of beef, 10/40 (25%) of mutton, and 5/30 (16.67%) of meat contact surfaces. Seven isolates were identified as S. Enteritidis, three as S. Typhimurium, and two as S. Typhi, while the rest of the isolates were considered as other Salmonella spp. All of the isolates were resistant to at least one antimicrobial agent and 48.27% of them were identified as multidrug-resistant (MDR) Salmonella. All (100%) of meat contact surfaces isolates, 42.8% of beef isolates, and 30% of mutton isolates were found to be MDR Salmonella. Resistance to nalidixic acid (100%), tetracycline (79.3%), and sulphamethoxazole/trimethoprim (44.8%) were observed. The gyrA gene was detected in 19 of 29 isolates, but tetA was found in one isolate. All of the serotypes were able to form biofilm (75.86 % moderate and 24.14 % strong) and S. Enteritidis was the strongest biofilm producer. The findings indicated that the majority of Salmonella isolates in this study were MDR and biofilm producer. Then, safety measures such as cleaning and disinfection must be taken to control Salmonella and promote public health. PRACTICAL APPLICATION: The present study provides useful information on the prevalence of Salmonella serotypes in meat and meat contact surfaces and their antibiotic resistance patterns as well as biofilm formation capacities. Improving hygiene practices in livestock, slaughterhouses, and at retails may reduce the risk of meat contamination to Salmonella. Meanwhile, high levels of antibiotic resistance in Salmonella isolates emphasized on the improper use of antibiotics.