مجله میکروب شناسی مواد غذایی
سال سوم شماره 1 (بهار 1395)

The need to replace synthetic preservatives with a natural resource has caused the food manufacturers to use from the medicinal plants as a reservoir. The present study was carried out to evaluate the antimicrobial effects of essential oils extracted from Origanum vulgare, Mentha piperita and Carum carvi on the Escherichia coli, Staphylococcus aureus and Salmonella typhimurium isolated from food products. After preparation of medicinal plants, essence extraction was done using the Clevenger device and antimicrobial effects of essences were evaluated on Escherichia coli, Staphylococcus aureus and Salmonella typhimurium isolated from raw milk and meat. Diameter of inhibition zone each essence was determined using the simple disk diffusion method on Mueller-Hinton agar. Bacterial isolates of meat were more resistant to all tested essences but the pattern of the effectiveness of essential oils on isolated strains was similar in both sources. Essential oil extracted from Origanum vulgare had the highest antimicrobial effect on S. aureus and the lowest on E. coli, Mentha piperita had the highest antimicrobial effect on E. coli and the lowest on S. aureus and Carum carvi had the highest antimicrobial effect on S. aureus and the lowest on S. typhimurium. According to the antibacterial effects of the mentioned essential oils, the possibility of their application as an antimicrobial preservative in meat and its products and also dairy products dairy is existing.

From desirable characteristics of electrolyzed water could be noted to inexpensive, safe, and no adverse impact on the environment. The aim of this study was to evaluate the influence of exposure time to neutral electrolyzed water on the reduction of contamination to Salmonella typhimurium and E.coli on skin and fresh poultry fillets. The neutralized electrolyzed water with 100 ppm free available chlorine was used for the exposure times of 1, 5, 10, 15 and 30 minutes on the inoculated skin (6 log/cm2) and chicken fillets (6 log/g) with mentioned bacteria. The results showed that the reduction of studied bacteria in skin and poultry fillets exposed to neutral electrolyzed water were statistically significant in comparing to distilled water (P

In spite of novel progresses in the methods for foodstuff’s preparation and production, consumer’s health and safety in the public hygiene import increasingly. One of the ways to control sickening microorganisms is the use of chemical retentive in the food. Today consumers are complaining to use natural retentive that are derivatives of herbaceous resources. As for harmful effects of food’s synthetic and chemical retentive. This study performs as for determining antibacterial Effects of Digitalis plant’s extracts on Staphylococcus aureus pathogenic bacteria in the foodstuff. In this study the ethanol extract alone and in combination with ciprofloxacin antibiotic on gram-positive bacteria, Staphylococcus aureus (ATCC25923), were evaluated by micro broth dilution method. MIC test results for Digitalis plant extract and Ciprofloxacin antibiotic evaluated 4.9 mg/ml and 0.5 μg/ml. effect of both extract and antibiotic results showed that growth of Staphylococcus aureus in the simultaneous use of 3.5 mg/ml extract and 0.28 μg/ml was inhibited by antibiotics. Evaluation of MBC tests for Digitalis plant extract and ciprofloxacin antibiotic evaluated 7.1 mg/ml and 1 μg/ml, results show that the combination of 4.2 mg/ml of extract and 0.14 μg/ml antibiotics cause the bacteria is eliminated. Concomitant use of alcohol extract and antibiotics, decreasing 48 percent of antibiotic to inhibit the growth of Staphylococcus aureus, and simultaneous use of alcohol extract and antibiotic, antibiotic use decreased 86 percent in the MBC for Staphylococcus aureus.

Food-borne illnesses are major international public health concern and significant cause of reduced economic growth. Contaminated food is the usual source of human infections, and poultry and beef meat are considered the major infectious route for humans. Each year, millions of persons become ill from foodborne diseases, though many cases are not reported. To assess the microbiological quality and safety of beef and poultry meat and try to achieve the connection of its contamination with hygienic conditions of packaging and without packaging of food in this study we analyzed food borne pathogens (Salmonella, Staphylococcus aureus and Bacillus cereus) in Gilan Province. A total number of 380 beef and poultry meat samples (with packing and without packaging) were collected and studied. Out of which 5/5 percent were founded contaminated with Salmonella 20.5 percent were founded contaminated with Staphylococcus aureus while 11.8 percent were founded contaminated with Bacillus cereus. Also 13.9 percent (beef meat) and 23.9 percent (poultry meat) were contaminated. The study confirmed the presence of Salmonella, Staphylococcus aureus and Bacillus cereus in beef and poultry meat which is potential threat to consumer health. To reduce of contamination, good hygiene practices are necessary from processing to storage.

In today's world, there is a growing tendency towards producing healthy and nutritious food. Mint is a genus of plants that its healthy and nutritious effects have been proved. Adding probiotic bacteria to yogurt increases its nutritious benefits. This study aims at adding the extract and fiber of mint stalk to stirred yogurt containing Bifidobacterium Lactis bacteria (BB-12) as well as examining the viability of this bacterium. To do so, the response surface methodology and the central composite rotatable design were employed. The findings obtained from the analysis showed that there was a significant relationship between different concentrations of fiber and extract, and the viability of B. Lactis bacteria in the first day to the 21st day (P

Nowadays, application of antimicrobial films for food packaging have been increased. The present study was carried out in order to investigate the antimicrobial activity of chitosan films containing 1–4% (v⁄v) Lavandula stoechas essential oil (EO) on some food-borne pathogenic bacteria (Listeria monocytogenes, Bacillus cereus, Vibrio parahaemolyticus, Staphylococcus aureus and Escherichia coli O157:H7). Circular discs of chitosan films containing different concentration of Lavandula stoechas essential oil were placed on bacterial lawn. The result of this study showed Incorporation of chitosan film with EO showed significant antimicrobial effects (P

Campylobacter spp. infections are of the most important foodborne diseases in many countries causing diarrhea in consumer. In this study, a total of100 edible mushrums (Agaricus mushrooms) were purchase in order to detection and identification of Campylobacter jejuni and Campylobacter coli at 2014 year in retail market of Shahrekord city, Central of Iran. All of the samples were cultured in enrichment and specific bacteriological media and then used for Polymerase Chaine Reaction (PCR) method for detection of C. jejuni and C. coli. Out of 100 samples, 15 % were found to be contaminated with Campylobacter spp. From 15 positive samples, 13.3 % and 86.7 % were positive for C. jejuni and C. coli, respectively. Therefore the consumption of raw edible mushrum to C. jejuni and C. coli constitutes health hazard for human in this city.

The purpose of this study is to provide a predictive model of Escherichia coli growth undr different conditions such as heat storage (8 ° and 37 ° C) and pH (4, 5 and 6) in a commercial chicken extract. For this purpose, a commercial extract of chicken prepared using acetic acid and 0/1 normal profit on the desired pH was adjusted. The level of 105 cfu / ml of E. coli extracts prepared to be inseminated. 8 and 37 ° C extracts were kept at two different temperatures and at different times of the sampling, dilution and the surface culture on Mac conkey Agar was developed. The results showed growth at pH 4 to 5 and 6 was significantly less than pH and reduces the growth of bacteria at temperatures of 8 and 37 ° C with no significant difference.