نشریه بهداشت مواد غذایی
سال سیزدهم شماره 3 (پیاپی 51، پاییز 1402)

The present study was conducted with the aim of investigating the effects of PLA- Iranian tragacanth gum composite film with Zygophyllum eichwaldi essential oil on the microbial characteristics of ostrich thigh meat stored at 4°C. For this purpose, first, 5 film treatments including: PLA, PLA+ gum and PLA+ gum with concentrations of 0.5%, 1.5% and 1.5% essential oil to determine the microbial properties of the film and then the effect of the mentioned films along with the control treatment (without film) was evaluated on the microbial factor (total bacterial count, psychrophilic bacteria, Enterobacteriaceae and lactic acid) in the ostrich fillet samples tested on days 0, 4, 8, 12 and 16 and the resulting data were SPSS software was analyzed. According to the results, adding essential oil to the film increased the antimicrobial activity of the films, and with increasing concentration, better results were observed (P<0.05) and the antimicrobial activity against gram-positive bacteria was higher than gram-negative bacteria. The results of the second part of this study showed that the samples packed with composite films containing essential oil showed lower (P<0.05) microbial changes than the control samples without essential oil during the study, and the film containing 0.5 and 1% of essential oil had the best effects compared to other groups (P<0.05). Therefore, the use of PLA- Iranian tragacanth gum film containing Zygophyllum eichwaldi essential oil in the packaging of ostrich meat has a very favorable effect in controlling the microbial characteristics effective in meat spoilage and increases its shelf life.

Nowadays, due to the existence of different occupations, it is not possible to cook food for all the people of a society, and most of the people have turned to using ready-made foods, which, in addition to all its advantages, can be a source of They are important bacterial contaminations that cause the spread of gastroenteritis. In this regard, the aim of this study is to investigate the prevalence of Arcobacter, Pseudomonas, Campylobacter and Bacillus cereus in sandwiches offered in Qom city and the antibiotic resistance of the isolates. 120 samples, including 30 samples of samosas, salads, traditional chicken nuggets, traditional hamburgers from the supply centers of Qom city, were randomly separated and transported to the food hygiene laboratory of Shahrekord Azad University along with ice flasks to prevent secondary contamination. The standards were evaluated. The results showed that Arcobacter 28.83%, Pseudomonas 16.65%, Bacillus cereus 23.35% and Campylobacter 14.75% were the highest and lowest contamination rates for Arcobacter and Campylobacter respectively. The highest level of resistance to antibiotics was related to Bacillus cereus with 78.56% and the lowest resistance was related to Campylobacter with 53.7%. Therefore, it is recommended to reduce the consumption of street food to a minimum, and in case of gastroenteritis caused by food contamination, the use of antibiotics should also be minimized.

Clostridium difficile is an obligate anaerobic, spore-forming bacterium with a length of 3-5 micrometers and most important enteropathogens in humans and livestock. Antibiotic use has been introduced as one of the most important risk factors in the spread of this disease. Antibiotics such as amoxicillin, erythromycin, lincomycin, clindamycin, linozoid, metopenem, metronidazole, amoxifloxacin, penicillin, pyracillin, tetracycline, and vancomycin have been introduced as common cases of "nosocomial Clostridium difficile infection". The purpose of this study is to investigate the prevalence, antibiotic resistance and genetic diversity of Clostridium difficile bacteria as a possible new foodborne pathogen in 300 domestic and industrial chicken and turkey meat samples in Chaharmahal and Bakhtiari provinces. The samples were grown in CDMN agar culture medium after an enrichment step to isolate Clostridium difficile. To determine the characteristics of the toxin, tcdA and tcdB genes were identified through multiplex PCR. The antibiotic sensitivity of these isolates was monitored based on the MIC test. The results showed that the highest prevalence was related to native chicken meat (5.6%) and the lowest prevalence was related to industrial turkey meat (1%). The genes responsible for the production of tcdB and tcdA toxins were observed in all Clostridium difficile isolates. Also, the highest resistance was related to erythromycin (14.85%) and the lowest resistance was related to vancomycin (97.38%). According to the isolation of two main genes causing hospital infection in clinical environments in the present study, the establishment of health systems in relation to the storage of the studied meats is necessary..

Dry leaf of trees, their powder and essential oil are used as flavoring agents in the food industry, and due to their antimicrobial and antioxidant properties, they increases the shelf life of food. The aim of this research is to investigate the chemical and antimicrobial properties of bay leaf essential oil. Extraction of essential oils was done by clevenger method. The results showed that the amount of carbohydrate, total fat and protein in the leaves were 2.93, 6.51 and 6.33 grams per 100 grams of dry matter, respectively, and antioxidant activity, total phenol and flavonoid content of the prepared essential oil, respectively, with IC50 of the number is 0.91 micrograms per milliliter, 0.65 m/g of gallic acid and 0.07 m/g of quercetin. The results of GC-MS showed that the main components of the essential oil include cineole (33.63 %), camphene (19.76 %), eugenol (11.73 %), terpineol (5.30 %), alphapinene (45.45 %.), Sabnin (3.42%), alpha-terpineol (0.45%) and methyl eugenol (0.33%). The evaluation of the antimicrobial activity of laurus nobilis essential oil indicates that the produced essential oil had antimicrobial activity against Staphylococcus aureus with a halo diameter of 14.60 ± 0.47 mm, while it was effective against Escherichia coli and Salmonella bacteria, respectively. It had less effect with halo diameter of 10.60 ± 0.47 and 9.60 ± 0.47 mm.

Meat products are one of the suppliers of human food needs, and like other food products, they have special nutritional values. If these products are contaminated with pathogenic microorganisms, they cause gastroenteritis in humans. The purpose of the present study is the prevalence of contamination of sandwiches with pathogenic microorganisms and the antibiotic resistance of isolates in Kermanshah, Iran. A number of 210 samples, including ready-made sandwiches, sauces and salads, were taken from the supply centers of these products and transferred to the laboratory of Kermanshah University of Medical Sciences and according to the standard instructions, to identify the microorganisms of Escherichia coli, Salmonella, Clostridium, coliform, Mold and yeast, Bacillus cereus, Staphylococcus aureus and Yersinia enterocolitica were evaluated. Antibiotic resistance of isolates was evaluated by disk diffusion method. The results showed that the highest contamination was related to mold and yeast (83.64 percent), Staphylococcus aureus (42.71 percent), Salmonella (32.1 percent), and Escherichia coli (27.8 percent). Clostridium perfringens (13.3), Yersinia enterocolitica (5.25) and Bacillus cereus (3.94). Also, the results showed that the most contaminated food items are salad (43.81 percent), sauce (42.38 percent), traditional hamburger (36.48 percent), samosa (32.85 percent), falafel (24.28 percent), respectively. percent), sausage (24.12 percent) and sausage (13.9 percent). The high and alarming prevalence of bacterial contamination as well as the antibiotic resistance of isolates in sandwiches is a warning to apply accurate and quick health monitoring to these products.

This study aims to compare the antimicrobial properties of nisin and natamycin in pasteurized liquid egg whites. After breaking and processing the eggs and performing operations such as filtration and homogenization, the egg white liquid undergoes pasteurization at 56-57 °C for 10 minutes with a flow rate of 1800 m3/s. Following pasteurization, the liquid is mixed with 0.08% and 0.1% solutions of nisin and natamycin in packaging tanks. Microbial tests are conducted at 0, 7, 14, and 30 days of storage. Based on the results, the antimicrobial effect of both natural preservatives nisin and natamycin in the microbial tests of total count, coliform, mold, and yeast have a significant difference at the probability level of 5%. In the total count test, 0.1% nisin on the seventh day exhibits the lowest total count (1.71 log CFU/gr), while the control sample on the 30th day shows the highest (4/49 log CFU/gr). For natamycin, 0.1% on the seventh day and 0.08% on the seventh day have the lowest counts (2.63 log CFU/gr and 2.67 log CFU/gr) respectively, and the control sample on the 30th day has the highest (4.5 log CFU/gr). No microorganism growth is observed in samples containing nisin and natamycin for coliform, mold, yeast, Escherichia coli, Staphylococcus aureus, and salmonella tests. Nisin demonstrates a more intense reduction in total count compared to natamycin, indicating superior antimicrobial properties and increased shelf life over time.