نشریه بهداشت مواد غذایی
سال هشتم شماره 2 (پیاپی 30، تابسنان 1397)

Meat is considered as an excellent and nutritious source of protein. However, due to the high cost of this animal protein and economic profit access of some producers, frauds like usage meat species of commercially lower value are noticeable. In this study is tried to identifiy low cost protein such as chicken meat that is not commonly used in meat products, but there is the possibility of this fraud by molecular method. DNA was extracted from 10 kind of industrial premium burgers with beef´s title mention, and control samples involve raw beef and chicken meat. Then, simplex-PCR and duplex-PCR were run on the extracted DNA using specific primer´s of cytochrome b gene in beef and 12s rRNA gene in chicken. Specific genes of beef cytochrome b and chicken 12s rRNA amplified 274bp and 183bp fragments respectively in all premium burger samples in simplex-PCR and duplex-PCR. Amplification of fragments of 183 bp by simplex and duplex-PCR suggests adulteration of premium hamburgers by partial replacement of beef with chicken.

This research has been carried out in order to study the effect of the corn starch and the black pepper essential oil oral film on the shelf life of the silver carp fillet under the vacuum packaging in the refrigerator temperature. All the treatments (control: without coating and essential oil, treatment 1: 0.1% essential oil, treatment 2: 0.5% essential oil and treatment 3: 1% essential oil) were prepared each in three replicates with a starch cover to achieve the best effective rate of the oral film and essence.The results showed that the changes in pH and free fatty acid were increasing in all the treatments during the storage. In all treatments, the level of peroxide did not exceed the permissible limit. In addition, the level of volatile nitrogenous bases in all control, 0.1 and 0.5% essential oil treatments did not exceed the permissible limit from day 9 until the end of the maintenance day. The rate of mesophilic bacteria showed a statistically significant difference during the shelf life (p

Milk provides an ideal medium for bacterial growth and can be quickly infected with a variety of bacteria. Staphylococcus aureus is one of the major milk-borne pathogens. Considering the importance of S. aureus enterotoxins in milk as one of the main sources of food poisoning, it is necessary to isolate and to investigate various enterotoxins in foods. The present study was an attempt to detect enterotoxin encoding genes in S. aureus isolates obtained from buffalo raw milk in Khuzestan province. For this, 100 samples of buffalo milk were obtained from milk distribution centers in Khuzestan province in 2016. The samples were evaluated through microbial and molecular assays and the presence of enterotoxin-generating genes in S. aureus isolates. According to the results, 7 samples contained SEA enterotoxin gene, which accounts for the highest number and distribution percentage. Also, two samples had both SEA and SEB, 2 samples had both SEA and SEC enterotoxin genes, and 1 sample had four SEA, SEB, SEC and SEH enterotoxin genes, and two samples included both SEH and SEJ enterotoxins genes, and one sample included the SEJ enterotoxin gene and one sample included both SEH and SEC enterotoxin gene. The relatively high presence of Staphylococcal enterotoxins encoding genes and the potential role of enterotoxin in human food poisoning indicates the significant role of buffalo milk as one of the human infection sources and the necessity of taking measures to prevent primary and secondary milk contamination by this bacterium.

Bacillus cereus is a gram-positive and spore-forming bacterium which is widely distributed in nature. It also has been known as a major food borne pathogen that often plays a role in the contamination of ready-to-eat and dairy products. It causes two different types of food poisoning in human: the diarrheal type and the emetic type. The aim of this study was to isolate and enumerate B. cereus in raw milk distributed in the stores of Tabriz city, Iran and to detect ces gene among the isolates. For this purpose, 120 samples of raw milk were randomly selected from the stores during February to June 2017. They were transferred to the Laboratory of food hygiene under sterile conditions in order to isolate, identify and enumerate B. cereus according to the national standard method of Iran and PCR. According to the results of microbial culture, out of 120 samples of raw milk, 13 (10.83%) samples were contaminated with B. cereus and the mean rate of contamination was 2.8 log10/ml. PCR results showed that of 13 positive samples, 12 (92.3%) samples contained ces gene which is responsible for vomiting. The results of this study showed that raw milk has the potential for human intoxication by B. cereus; and the use of procedures to reduce the bacterial contamination during the processing of dairy product is required.

Triglycerides are the most abundant form of fats in human bodies and plants. They are also the most important type of fats that are present in the diet. Physicochemical properties of the fats are dependent on the kinds and amount of fatty acids present in their structure. Therefore, to evaluate their quality, these two factors i.e. kind and amount of fatty acids have to be investigated. So in the present study, the fatty acids profile of some edible oils and confectionary oils (Minarines) were quantitatively and quantitatively investigated. In this study myristic acid (C14), palmitic acid (C16), stearic acid (C18), oleic acid (C18:1cis), elaidic acid (C18:1T), linoleic acid (C18:2) and linolenic acid (C18:3) were extracted simultaneously from 60 samples of edible oil and 10 samples of minarine oil, using liquid-liquid extraction followed by GC-FID procedure. The obtained results showed that 16 samples of the tested oil (22.8%) contained trans-fatty acids higher than 2% (w/w), of which 6 samples were hydrogenated oils and 10 samples were confectionary oils. Also, the sum of saturated fatty acids in 14 samples (20%) was over 30% of which 4 samples were frying oils and 10 samples were confectionary oils. Altogether, based on the regulations of the Institute of Standards and Industrial Research of Iran, 27 samples (38.5%) were identified as not usable.

Spices and seasonings are of herbal origin and are used to improve the aroma, flavor, and color of foods. Similar to the other agriculture products, microbial contamination of spice plants are a great challenge to the wholesomeness of foodstuff. Enterobacteriaceae are of great concern in food hygiene so that the determination of enteric bacteria is the most regular assay for the evaluation of food safety. This study aimed to investigate the microbiological load and the diversity of enteric bacteria in spices and herbs marketed in Tabriz. A total of 125 samples consisting 25 types of spices and herbs from 5 distinct regions of Tabriz was collected. According to the results, all samples contained aerobic mesophilic bacteria and coliforms. In 28% and 40% of the samples, the mean population of aerobic mesophilic bacteria and coliforms were beyond the ICMSF limit, respectively. Moreover, 110 isolates of enteric bacteria consisting 13 various species were identified. Highest and lowest occurrence rate of enteric bacteria was determined as Escherichia coli (21.81%) and Salmonella enterica (0.9%), respectively. Excessive microbial contamination of the samples and particularly, the presence of various enteric bacteria -with the potential of pathogenicity- is considered as an indication of health hazard. Therefore, it is necessary to apply appropriate decontamination procedures such as thermal processes, ozone treatment or irradiation in order to eradicate the microbial contamination of spices.

One of the major concerns in modern societies is applying the chemical additives in food products and the risk of catching some types of diseases such as cancer. The aim of this research was investigating the possibility of nitrite substitution in cocktail sausage formulation by using black cumin oil. For this purpose different levels of nitrate in 0, 30, 60 and 90 ppm was replaced with black cumin oil at concentrations of 2 and 3 percent and its effects were evaluated on oxidative stability (peroxide and thiobarbituric acid indices), microbial properties (total bacterial count and yeasts and molds count), and sensory characteristics during one month of storage at 4 °C at 1, 11, 21, and 31 days. The results showed that replacement of nitrite with black cumin oil in two used concentrations led to a reduction of the peroxide and TBA values in nitrite reduced sausages compared to control (P

Among the growing concerns over recent decades in the field of environmental pollution, is the use of antibiotics increase bacterial resistance to antibiotics used in human body. The aim of this research was to synthesis of Molecularly Imprinted Polymer (MIP) particles for the Oxytetracycline (OTC) antibiotic removal from the aqueous and milk. The influence of different parameters such as pH (2-10), contact time (5-120 min) and MIP amounts (0.1 – 1.0 g/L) was studied on optimization of OTC removal. The synthesized MIP particles was characterized by scanning electron microscopy and absorption and desorption of nitrogen (BET). The results showed that the removal efficiency is higher in neutral pH and with increasing amounts of MIP particle, removal efficiency increases. The best condition for OTC removal was determined at pH, 6.5, 90 min and 280 mg/g as maximum absorption capacity. The MIP performance for OTC removal from milk was investigated too. The performance of MIP polymer particles in OTC removal in milk samples supplied from an animal husbandry in Yazd showed that these adsorbents can help to effectively reduce the residues of drug contaminants in dairy samples.