negin karami

The aims of the present work were to add Zingiber officinale extract 0.25% and 0.5% into the chitosan-poly(vinyl alcohol) film by casting method and investigate their utilization as antimicrobial packaging polymer in retarding the chemical spoilage and microbial growth during prolonged shelf-life storage of chicken fillets. Fresh chickens were purchased from a local poultry processing plant (Kermanshah, Iran). 100 g of chicken fillet samples were packaged with designated films and maintained at 4 ± 1 °C for 10 days. Total viable count, psychrotrophic bacterial count, Enterobacteriaceae, and peroxide value of chicken fillets were evaluated during refrigerated storage conditions. The microbial counts and peroxide value of all prepared treatments significantly incremented over a 10-day storage time, while the growth rate of microorganisms and chemical changes in the control and fillets packaged with straight chitosan-poly(vinyl alcohol) film were higher comparing with other treatments. Total viable count, psychrotrophic bacterial count, Enterobacteriaceae, and peroxide value of chicken fillets packaged with chitosan-poly(vinyl alcohol) film + Zingiber officinale extract 0.5%, as the best treatment, were 6.73 log CFU/g, 3.95 log CFU/g, 3.89 log CFU/g, and 0.82 meq peroxide/kg lipid, respectively, at the end of the study period. The results indicated that the designated films could be a promising method to extend the shelf-life of chicken fillets’ quality during refrigerated storage.

The utilization of plant essential oils and extracts as antibacterial agents has given specific attention to prevent the growth of pathogenic bacteria. This work aimed to compare the effects of sodium metabisulfite and Mentha longifolia L. essential oil (MEO; 0, 0.5, 1, and 2%) for growth prevention of Listeria monocytogenes and Escherichia coli O157:H7 in peeled giant freshwater prawns under cold storage for two weeks.   The in vitro antimicrobial effect of MEO against L. monocytogenes and E. coli O157:H7 was evaluated using disk diffusion method. In this study, the effect of direct addition of MEO (0, 0.5, 1, and 2%) and sodium metabisulfite 1.25% to prawn samples were evaluated.  The major chemical constituents of MEO were found to be pulegone (47.20%), eucalyptol (22.72%), and menthone (13.44%). The diameter of inhibition zone of MEO against L. monocytogenes and E. coli O157:H7 were determined to be 9.45 ± 0.23 mm and 6.37 ± 0.02 mm, respectively. Our findings indicated that MEO 0.5, 1, and 2% significantly decreased the growth of L. monocytogenes and E. coli O157:H7 in comparison with the control group (P < 0.05). Sodium metabisulfite was more effective than MEO in inhibiting the growth of L. monocytogenes and E. coli O157:H7 added in raw freshwater prawns.  The findings of this work indicate that MEO can successfully prevent the growth of L. monocytogenes and E. coli O157:H7 and improve the safety of raw freshwater prawns under prolonged refrigerated storage.

Various natural oils/extracts and their constituents incorporated into biopolymer-based edible films as a promising technology with the knowledge that these compounds have been able to reduce microbial growth and chemical changes of packed foodstuffs. The objective of this study was to evaluate the effect of incorporation of Ziziphora clinopodioides essential oil (ZEO; 0, 0.25 and 0.5%) and sesame oil (SO; 0, 0.5 and 0.75%) into chitosan-flaxseed mucilage (CH-FM) film against Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus and Escherichia coli O157:H7 in vitro condition and raw minced trout fillets during refrigerated condition. The in vitro antibacterial and antioxidant properties of CH-FM films were evaluated using agar disk diffusion method and free radical scavenging activity assay, respectively. The most important constituents of ZEO were found to be carvacrol (65.22%), thymol (19.51%), ɣ-terpinene (4.63%) and p-cymene (4.86%). The lowest and highest antimicrobial effect against S. aureus, L. monocytogenes, E. coli O157:H7 and S. typhimurium were found for CH-FM films enriched with SO 0.5% (0.98-1.24 mm) and ZEO 0.5% + SO 0.75% (5.01-6.25 mm), respectively. The antioxidant property of CH-FM based films were found to be ranged 5.45% ± 0.04-37% ± 0.45. In treated trout fillets, the counts of L. monocytogenes, S. aureus, E. coli O157:H7 and S. typhimurium were 1.54-4.18, 0.34-3.35, 0.29-1.45 and 0.19-1.27 log CFU/g significantly lower than control groups after two weeks of refrigerated storage, respectively. The designated films had good antibacterial effect against some food borne pathogenic bacteria including L. monocytogenes, S. aureus, S. typhimurium and E. coli O157:H7 in raw rainbow trout fillets.

Poultry nutrition or inappropriate treatments by antibiotics can lead to production of eggs with antibiotic residues. The aim of the present study is to assess the prevalence of drug residues in eggs presented in Kermanshah, Iran. For this purpose, 120 eggs with the average weight of 60 grams were collected randomly from the supermarkets in Kermanshah and later were tested for antibiotic residues using the Four- Plate Test (FPT) method. The results showed that 3.3% of the tested eggs had antibiotic residues. The main residues in egg yolk was due to tetracycline. Aminoglycosides were also detected as minor contaminants. Accordingly, antibiotic residues in eggs presented in Kermanshah are a threat for human consumption and therefore strong supervision of the authorities is essential.

Essential oils usually exhibit different characteristics such as antimicrobial and flavoring effects. The aim of the present study was to investigate chemical composition and in vitro antibacterial activity of the essential oil of Ferulago angulata (Schlecht.) Boiss aerial parts against bacterial food-borne pathogens (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium and Escherichia coli O157:H7). The chemical composition of the essential oil was analysed by gas chromatograph coupled with mass spectrometer detector (GC-MS). The antibacterial activity of the essential oil was assessed using broth micro-dilution and agar disk diffusion methods. According to results of GC-MS analysis, 33 constituents were identified. The dominant components were α-pinene (28.43%), (Z)-beta-ocimene (20.12%), bornyl acetate (7.92%), ɣ-terpinene (5.72%), germacrene D (5.63%), myrcene (4.67%) and p-cymene (2.17%). The results obtained in this study showed that L. monocytogenes and B. cereus had the most sensitivity to the essential oil (MIC and MBC= 40µg/mL; Inhibition zone: 9mm). Our results indicated that F. angulata essential oil might be a potential rich source of compounds with antibacterial properties against food-borne bacteria.

Improving cleaning and disinfection performance must be taken into account for prevention and control of infection. Health care settings are engaged in a battle against healthcare associated infection (HAIs). The importance of infection prevention and control is increasing due to rapidly developing strains of multi-drug resistant organisms (MDROs) that can result in serious illness and even death in workers and patients. There are many cleaning and disinfectant protocols used in health care centers and hospitals. Conventional cleaning and disinfecting methods are not completely effective. On the other hand, some of these products are known or suspected to be associated with eye, skin irradiation, respiratory disorders and allergies. Concerns about adverse human health effects of conventional cleaning and disinfecting products have led to the development of new methods to achieve better results and less adverse effects. Some of these procedures may reduce human health effect as well as reduce costs.