نشریه بهداشت مواد غذایی
سال یازدهم شماره 1 (پیاپی 41، بهار 1400)

To improve the quality and increase the shelf life of agricultural products, many pesticides are widely used. Although the use of pesticides in agricultural applications provides a wide range of beneficial effects, overuse of these substances results in their accumulation in soil, surface water, and foods. The analysis of pesticide residues is thus very important for the health of consumers. In this study, a combined extraction method of QuEChERS based on deep eutectic solvents and DLLME method for the extraction of Hexaflumuron, Chlorfluazuron, Flufenoxuron, Diafenthiuron, and Diflubenzuron benzoylurea pesticides from fruit samples of grape, apple, cherry, apricot, and orange and then analyzing them using high-performance liquid chromatography with diode array detector is presented. According to the results, the proposed method is simple, reliable, and inexpensive with low organic solvent consumption and has a short analysis time, and indicates good values extraction efficiency, so that under optimal conditions, limits of detection and quantification were obtained in the range of 3.3-6.5 and 11.2-22.2 ng/ml, respectively. Recovery rates and enhancement factors ranged from 52% to 88%. In actual samples, only Flufenoxuron insecticide present in one grape sample was detected at 17 0.5 ng/ml.

Marinating meat in solutions containing organic acids and plant extracts reduces the microbial load and increases its shelf life. In the present study, the effect of marinating camel meat with an aqueous extract of ginger and citric acid was investigated on the growth rate of Staphylococcus aureus and Escherichia coli bacteria and changes in pH and total volatile nitrogen (TVN). For this purpose, camel thigh meat samples were divided into 8 groups, including the control group (marinated in distilled water) and groups marinated with citric acid (0.5, 1.5, and 1.5%) and groups marinated with a combination of aqueous extract of 30% ginger and citric acid (0.5, 1.5 and 1.5%). The samples were stored at 4 °C and after 24 and 48 hours, microbiological and chemical tests were performed. The results showed that there was a statistically significant difference between the control and other groups (P˂ 0.05). The Control group showed the highest microbial growth in both time intervals. The lowest pH was observed in 1.5% citric acid marinade, while the highest pH was related to the control group and ginger extract solution. The Control group showed the highest TVN after 48 h (P˂ 0.05). Based on the results, it can be concluded that changes in the concentration of citric acid and ginger extract affected the growth of S. aureus and E. coli inoculated on camel meat and increased its shelf life in refrigerated temperatures.

Bisphenol A is a chemical substance that impairs estrogenic endocrine and the presence of BPA in water causes various problems for human health. The present study aims to evaluate the amount of BPA in bottled waters in Ardabil and to optimize the ozone condition for reducing it in water. For this purpose, 5 samples were selected out of 13 brands of bottled water. One sample of each brand was tested on the first day and 4 other samples were tested after 30 days of storage at temperatures of 5, 15, 25, and 40 °C using a high-performance liquid chromatography device. To determine the ozonation efficiency, at first, the concentration of consuming ozone, pH of the environment, duration of ozonation, and initial concentration of BPA were optimized and then tested under optimal conditions. On the first day, the amount of BPA in all brands was within the limits allowed by the Department of Health of America (20 µg/L). By increasing the temperature of storage, the amount of BPA increased in all samples and at 40 °C, its amount exceeded the allowable limit in 3 brands. Optimal conditions are achieved at an ozone concentration of 6 mg/l, pH equal to 7, concentration of dissolved BPA equal to 10 mg/l, and ozonation time in 10 minutes. Furthermore, ozonation in these conditions removed 90% of BPA in water. In general, it can be declared that the contamination of BPA in bottled waters increases during preservation, and especially at temperatures higher than a refrigerator (out of the refrigerator), and ozonation under optimized condition is an effective method to reduce it.

Toxoplasmosis is one of the most dangerous common protozoan diseases between humans and animals that infect humans in various ways. Contact with the infected animal, consuming contaminated food, and transmitting from mother to fetus is the most important means of transmission. Based on the recorded data, this study is the first report of Toxoplasma gondii in buffalo and camel milk in some parts of Iran. For this purpose, 440 raw milk samples of 5 species of animals were collected from Isfahan, Chaharmahal & Bakhtiari, Khuzestan, and Fars provinces during four seasons and studied for the presence of Toxoplasma gondii by nested-PCR. The results showed that 26 (5.9%) of the samples were infected with Toxoplasma gondii. The highest infection was observed in sheep milk (8%) and the lowest in buffalo milk (4.28%). The seasonal prevalence of infection was in winter (11.43%), autumn (6.8%), and spring (5.03%), while none of the samples obtained in summer the parasite was not infected. Contamination of raw milk and traditional dairy products with Toxoplasma gondii can either occur directly from infected animals or as a result of non-compliance with the principles of hygiene during the process of milking, transportation, storage, and cross-contamination. Therefore, proper pre-consumption of milk is recommended.

The use of the microencapsulation technique can lead to an increase in the survival of probiotics in dairy products during storage. Chemical modification is one of the proposed strategies to improve the protective ability of alginate used in microencapsulation. In the current work, the effect of succinylated alginate and its application as a micro-coating on the preparation of Lactobacillus acidophilus microcapsules was evaluated on the qualitative properties (pH, acidity, syneresis, and water holding capacity), sensory properties, and survival of this bacteria in yogurt during 21 days of storage at 4°C. For this purpose, four samples of yogurt including yogurt without L. acidophilus, yogurt containing free L. acidophilus, yogurt containing microencapsulated L. acidophilus with native alginate, and yogurt containing microencapsulated L. acidophilus with succinylated alginate, was prepared. The results of qualitative tests showed that the acidity and syneresis of yogurt containing succinylated alginate microcapsules were lower while the pH and water holding capacity were higher than the other experimental groups. Also, the results of microbial counting and sensory evaluation showed that the microencapsulation of L. acidophilus using succinylated alginate was significantly increased its survival during the storage time (p < /em><0.05) without any adverse effects on the sensory properties. Therefore, microencapsulation with succinylated alginate can be suggested as an effective approach to improve the survival of probiotics in yogurt.

Beef is considered the main source of dietary protein despite being perishable. In this regard, utilization of biodegradable films containing plant essential oils, as antimicrobial compounds, is one of the concepts to prolong the beef shelf life. Accordingly, this study aimed to investigate the effect of the biodegradable film based on orange waste powder (OWP) containing nettle essential oil (NEO) and cellulose nanofiber (CNF) to increase the shelf life of the refrigerated beef samples stored for 12 days. As well, beef samples were divided into three groups of uncovered (control), wrapped with the OWP-based film without essential oil and nanofiber and wrapped with OWP-base film containing 3% NEO and 6% CNF and the microbial (aerobic mesophilic count, psychrophilic count, and coliform count) and chemical (pH, thiobarbituric acid and volatile nitrogen bases) properties were evaluated at regular intervals (0, 4, 8 and 12days). According to the results, the beef sample wrapped with OWP-base film containing 3% NEO and 6% CNF showed the lowest growth rate of the mentioned bacteria after 12 days of storage; Moreover, the samples covered by the film containing NEO and CNF had lower levels of pH, thiobarbituric acid and volatile nitrogen bases values compared to the other two samples at 12th day of storage. The results of this study indicate that wrapping beef samples with an OWP-based nanobiocomposite film containing 3% NEO and 6% CNF could remarkably prolong its shelf life in refrigerated conditions.

Cyanobacteria and microalgae have great potential to produce a wide variety of biotoxic and non-toxic biologically active compounds and could lead to the development of the food and pharmaceutical industries soon. The commercial proliferation of algae on a large scale is due to their ability to produce a wide range of valuable secondary metabolites such as polyunsaturated monounsaturated fatty acids, polysaccharides, glycerol, glycoproteins, antioxidant compounds, and antibiotics. Today, with the potential spread of bacterial resistance and reduced efficacy of existing antibiotics, researchers are looking to find new antibiotics among the products produced by microalgae. However, many cyanobacterial strains contain toxic compounds that cause the death of many humans and animals. In this review article, an attempt has been made to introduce valuable biologically active products along with various types of cyanotoxins in foods and treatment methods by collecting the latest research. It is hoped that the results of this study could pave the way for the introduction of valuable metabolites produced by cyanobacteria and microalgae in the food and pharmaceutical industries.