Investigating the effects of chitosan/ tragacanth gum/ polyvinyl alcohol composite coating incorporated with cinnamon essential oil nanoemulsion on safety and quality features of chicken breast fillets during storage in the refrigerator.

The present study investigated the effects of composite coatings made of chitosan (CS), tragacanth gum (TG), and polyvinyl alcohol (PVA) containing cinnamon essential oil (CEO) on the shelf-life of refrigerated chicken breast fillets. The samples were treated with different coating dispersions, and coded as: T1 (distilled water as control), T2 (blank composite coating), and T3 (composite coating containing CEO). Results showed that incorporating CEO into CS/TG/PVA coatings could significantly increase the quality of chicken fillets. The obtained results showed that after 21 days, the total microbial population of lactic acid bacteria (LAB), psychrotrophic and mesophilic bacteria in T3 samples was less than T1 and T2 samples. In addition, the highest antioxidant activity (48.04 %) and total phenolic content (TPC) values (2.458 mg gallic acid /g), the best sensory characteristics and the lowest pH (5.73), total volatile basic nitrogen (TVB-N) (21.89 mg N/100 g), thiobarbituric acid reactive substances (TBARS) (1.678 mg malondialdehyde equivalent/kg) and percentage of cooking loss (30 %) were related to T3. Results disclosed that this composite coating is a promising technology to improve the shelf life of chicken fillets during storage.

Fabrication, characterization and antimicrobial activity of chitosan/tragacanth gum/polyvinyl alcohol composite films incorporated with cinnamon essential oil nanoemulsion.

The aim of this investigation was to prepare and characterize active composite films made of chitosan (CS), tragacanth gum (TG), polyvinyl alcohol (PVA) and loaded with different concentrations of cinnamon essential oil (CEO) nanoemulsion (CEO, 2 and 4 % v/v). For this purpose, the amount of CS was fixed and the ratio of TG to PVA (90:10, 80:20, 70:30, and 60:40) was considered variable. The physical (thickness and opacity), mechanical, antibacterial and water-resistance properties of the composite films were evaluated. According to the microbial tests, the optimal sample was determined and evaluated with several analytical instruments. CEO loading increased the thickness and EAB of composite films, while decreasing light transmission, tensile strength, and water vapor permeability. All the films containing CEO nanoemulsion had antimicrobial properties, but this activity was higher against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) than Gram-negative types (Escherichia coli (O157:H7) and Salmonella typhimurium). According to the results of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD), the interaction between the components of the composite film was confirmed. It can be concluded that the CEO nanoemulsion can be incorporated in CS/TG/PVA composite films and successfully used as active and environmentally friendly packaging.

Corrigendum to "Determination of metal(oids) in different traditional flat breads distributed in Isfahan city, Iran: Health risk assessment study by latin hypercube sampling" [Toxicol. Reports 10 (2023) 382-388].

[This corrects the article DOI: 10.1016/j.toxrep.2023.02.015.].

Determination of metal(oids) in different traditional flat breads distributed in Isfahan city, Iran: Health risk assessment study by latin hypercube sampling.

This survey was conducted to assess the metal(oids) content in 93 samples of bread, including barbari, lavash, and tafton, using inductive couple plasma/optical emission spectroscopy (ICP-OES) method and atomic absorption spectroscopy (AAS). The amounts of measured element were compared with the permissible limit set for bread by FAO/WHO and Iranian National Standardization Organization (INSO). The limit of detection (LOD) was ranged from 6.6 × 10-5 to 2.1 × 10-2 mg l-1 with recoveries ranged from 92% to 102%. The average concentrations of aluminum (Al), arsenic (As), boron (B), cadmium (Cd), iron (Fe), mercury (Hg), magnesium (Mg), sodium (Na), lead (Pb), and zinc (Zn) in bread were 29.88 ±â€¯8, 0.03 ±â€¯0.004, 12.77 ±â€¯3.70, 0.01 ±â€¯0.006, 34.16 ±â€¯8.95, 0.01 ±â€¯0.008, 346.07 ±â€¯36.08, 3314.81 ±â€¯317.19, 0.24 ±â€¯0.11, and 19.65 ±â€¯4.66 mg Kg-1, respectively. Amounts of As, Cd, Hg, Mg, Pb, and Zn were lower, and those of Al, Fe, and Na were higher than the permissible limits defined by FAO/WHO. The Latin Hyper Cube (LHC) sampling results revealed that children were exposed to higher non-carcinogenic risk and adults were more threatened by carcinogenic risk. It is recommended to control the entrance of metals in bread in the farm-to-fork chain in order to prevent probable future health challenges.

Production, characterization, and antimicrobial activity of almond gum/polyvinyl alcohol/chitosan composite films containing thyme essential oil nanoemulsion for extending the shelf-life of chicken breast fillets.

In this study, thyme essential oil (TEO) nanoemulsion was immobilized within composite films based on almond gum (AG), polyvinyl alcohol (PVA), and chitosan (CS). The physical, mechanical, water barrier, microstructural and antimicrobial properties of composite films were assessed. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the intermolecular interactions in the composite film matrix. The results indicated that the incorporation of TEO into the composite films increased thickness, moisture content, and water vapor permeability, while it reduced light transmittance and transparency value. The antimicrobial activity of films against gram-negative and gram-positive bacteria was tested using a disc diffusion method. The effect of composite on the microbiological properties of chicken breast fillets was investigated during refrigerated storage for 21 days. The microbial populations of total mesophilic, psychrotrophic, and lactic acid bacteria of the samples that were coated with the composite containing TEO were lower than the permitted limit after 21 days while for blank samples they were higher than 7 log CFU/g after 7 days which is considered as the maximum acceptable total count limit. Results disclosed that AG/PVA/CS composite films containing TEO nanoemulsion can be applied as eco-friendly active food packaging to enhance the shelf-life of food products.

Prevalence and antibiotic resistance profile of Shiga toxin-producing Escherichia coli isolated from diarrheal samples.

BACKGROUND AND OBJECTIVES: Enterohemorrhagic Escherichia coli (EHEC) causes bloody and non-bloody diarrhea, intestinal infection and extraintestinal complications in humans. This study aimed to isolate and evaluate the prevalence of E. coli O157: H7 and other Shiga toxin-producing E. coli (STEC) and identify the virulence genes (stx1, stx2, hly and eaeA) from patients with diarrhea. Also, the antibiotic resistance profile of the isolated strains was evaluated. MATERIALS AND METHODS: A total of 100 stool samples were collected from patients with acute diarrhea referring to the hospital and clinics in Isfahan County, Iran. Phenotypic tests and PCR assay were used for detection of E. coli O157: H7 and other Shiga toxin-producing E. coli. The presence of virulence genes (stx1, stx2, hly and eaeA) were identified by PCR. The antibiotic resistance profile of the isolates was determined using the agar disk diffusion method. The results were analyzed descriptively by Sigma stat version 4 software. RESULTS: Seventy - eight out of 100 samples (78%) were contaminated with E. coli. E. coli O157 was isolated from five samples (6.4%), of which only two strains (2.56%) were identified as E. coli O157: H7. According to the results, out of two E. coli O157: H7 isolates, one (50%) isolate contained eaeA and two isolates (100%) contained Stx1, Stx2, hlyA genes. Out of three (3.84%) E. coli O157: HN, one of the isolate (33.3%) contained stx1 and, two isolates (66.7%) were positive for hlyA genes. Also, the results revealed that six strains (7.69%) were non-O157: H7 STEC, of which two isolates (33.3%) contained stx1 and four isolates (66.7%) were positive for stx2 and hlyA genes. The results of antibiogram tests revealed that all of the STEC isolates (100%) were sensitive to imipenem followed by kanamycin, gentamicin and nitrofurantoin (91%). High resistance (54.5%) to ampicillin and ciprofloxacin was observed among the STEC isolates. CONCLUSION: The results of the current study showed that although the prevalence of E. coli O157: H7 was low among patients with diarrhea, the other STEC strains with relative resistance to antibiotics are more prevalent.

Effect of Ganoderma lucidum Powder on Oxidative Stability, Microbial and Sensory Properties of Emulsion Type Sausage.

BACKGROUND: Ganoderma lucidum from Ganodermataceae family is a kind of mushroom known to have various therapeutic properties such as lowering high blood sugar and high blood pressure, boosting the immune system as well as its antibacterial and antioxidant effects. MATERIALS AND METHODS: this study investigated the oxidative stability, microbial and sensory properties of sausage at three different treatments; (i) 1% w/w Ganoderma lucidum powder (GLP) without nitrite as a food preservative (P), (ii) 0.5% w/w GLP with 80 ppm nitrite (N + P), and (iii) sausage with 120 ppm nitrate (N). Lipid oxidation was evaluated using peroxide value (PV) and thiobarbituric acid reactive species. Antimicrobial properties were assessed by total plate count (TPC), yeasts and molds, coliforms, Clostridium perfringens, and Staphylococcus aureus. Sensory assessment was evaluated by nine-point hedonic procedure. RESULTS: Samples in N + P treatment showed lower PV than other treatments at the storage period with no significant difference in 2-thiobarbituric acid (TBA) between N and N + P. The P group showed the highest TBA value (P < 0.01). TPC remained below maximal permissible limit recommended by ISIRI during 30 days of storage in all sausage formulations (6.9798 log CFU). There was not found any coliforms bacteria, Clostridium perfringens, and S. aureus. The sensory evaluation indicated that there is no significant difference between samples in texture, taste, and smell. The color and overall acceptability of N group were higher and N + P group was closer to N group. CONCLUSION: The results suggest that G. lucidum powder might be considered as a potential natural preservative for meat products.

Prevalence of Listeria monocytogenes in raw milk in Kerman, Iran.

Listeria monocytogenes as one of the most important pathogen in public health concerns is transmitted through consumption of contaminated food. The pathogen has been considered as a potential source of contamination of raw milk and dairy products. This research was aimed to investigate prevalence of L. monocytogenes in raw milk in Kerman region. In the summer of 2011, a total number of one hundred raw milk samples were collected from bulk tanks of some dairy farms and tested for iap and actA genes using polymerase chain reaction. Among the 100 samples, five isolates (5.0%) were detected as L. monocytogenes based on phenotypic and genotypic characteristics. Considering the low frequency of L. monocytogenes in this study, raw milk cannot be omitted as a potential source of food contamination for the population of the region. To achieve more accurate isolation, identification and control of L. monocytogenes in raw milk, it is suggested that new standard laboratory methods be implemented as well as biosafety outreach programs, management techniques and education.

Prevalence, predilection sites and pathological findings of Taenia multiceps coenuri in slaughtered goats from south-east Iran.

Coenurosis is a zoonotic disease in a variety of ruminants caused by the metacestode of Taenia multiceps. The coenuri in the brain and spinal cord of sheep and goats have been identified as Coenurus cerebralis whilst those reported in other tissues have been named Coenurus gaigeri. This study was conducted during the spring and summer of 2011. Out of 25 739 goats inspected in slaughterhouses, 23 carcasses (0.09%) revealed one or multiple visible swellings on the different muscles and visceral organs. The coenuri, of variable sizes, were found mainly in the muscles of the thigh, shoulder and neck, and were less common in the abdominal muscles and subcutaneous tissues. Coenuri were also found in the diaphragm, tongue, intercostal muscles, lung, parotid area and tunica adventitia of the aorta in a goat with severe infection. The brains of slaughtered goats that had coenuri in their skeletal muscles were examined and coenuri were found in two specimens (8.69%). The coenuri were located in the occipital lobe, the anterior part of the right cerebrum and the parietal lobe of the left cerebrum. Histopathologically, coenuri in the brain caused pressure atrophy and liquefactive necrosis in the surrounding tissues, hyperaemia, perivascular cuffing, neuronal degeneration, neuronophagia, satellitosis, diffuse microgliosis and astrocytosis. Coenuri in the skeletal muscles caused degenerative and necrotic changes, hyalinisation and myositis. In the lung, tissues around the coenurus revealed atelectasis and focal interstitial fibrosis. In the present study, concurrent occurrence of coenuri in the central nervous system and skeletal muscles supports the hypothesis that C. cerebralis and C. gaigeri are different names for the metacestodes of the same species of tapeworm.

Phylogenetic background and virulence genes of Escherichia coli isolates from colisepticemic and healthy broiler chickens in Iran.

The purposes of this study were to determine the phylogenetic background and the virulence gene profiles of Escherichia coli isolates from colisepticemic and feces of healthy (AFEC) broiler chickens. In this study, 253 E. coli isolates including 141 avian pathogenic E. coli (APEC) and 112 AFEC isolates were examined by PCR. In general, 253 E. coli isolates distributed among group A (51.8%), B1 (15.8%), B2 (8.7%), and D (23.7%). Ten (8.9%) AFEC isolates segregated in to B1 phylo-group and 102 (91.1%) isolates fell into six different phylogenetic subgroups. Distribution of colisepticemic and fecal isolates differed significantly in their assignments to A and B1 phylo-groups. The three most prevalent virulence genes were crl, fimH, and aer in isolates between both groups. The four genetic markers aer, papC, afa, and sfa were detected significantly more often among colisepticemic isolates than in fecal isolates from healthy broilers. The presence of stx ( 2 ) gene in fecal isolates were significantly differs among the colisepticemic isolates. F17 fimbrial family encoding gene and eae gene were detected in APEC and AFEC isolates, respectively. The colisepticemic and fecal isolates possessed the virulence genes were detected in all of the four phylogenetic groups. Several combination patterns of the virulence genes were detected in APEC and AFEC isolates. In colisepticemic isolates the combination of aer, crl, and fimH genes was the most prevalent pattern. None of the examined isolates harbored the cdt, cnf1, ipaH, and stx ( 1 ) virulence gene sequences.