فهرست مطالب amir rahimirad

Aflatoxin M1 (AFM1), a carcinogenic substance is found in milk and dairy products. The effect of season and type of dairy products on AFM1 level in northern Iran was investigated in this study. Three hundred samples (each season 75 samples) including raw and pasteurized milk, yoghurt, cheese, and cream samples were collected from three distinct milk producing farms. The samples were subjected to chemical and solid phase extractions and were analyzed by using HPLC technique. Recovery percentages, limit of detection and limit of quantification values were determined. Seventy percent and 98% were the minimum and maximum recoveries for cheese and raw milk, respectively and 0.021 and 0.063 ppb were the limit of detection and limit of quantification values for AFM1. We found that in autumn and winter the highest level (0.121 ppb) of AFM1 in cheese and cream samples and failed to detect any AFM1 in spring samples. Interestingly, our data showed that the yoghurt samples had the lowest level of AFM1 in all seasons. There are significant differences between the AFM1 levels in dairy products in various seasons and also various types of products, suggesting spring and summer yoghurt samples as the safest products from AFM1 level point of view.

Doogh is a traditional Iranian drink prepared by fragmentation and dilution of yogurt, with addition of salt and flavouring. Dairy products are favorable environment for microbial growth due to high nutrient and relative humidity. One of the most important parameters in the food industry production and consumption is enhancing the shelf life of the product. Therefore, food additives such as potassium sorbate are used in this regard. While application of potassium sorbate as a preservative with excellent antibacterial and antifungal properties in various foods is common, but its addition into Doogh is forbidden according to national standards of Iran. The objective of this study was to determine the prevalence of preservatives in Doogh in West Azerbaijan province, Iran, from 2011 to 2014. 172 samples of various commercial Doogh were tested for determination of potassium sorbate. The results showed that 14.6% of samples were contaminated with preservatives and the highest and average concentration of this preservative in analyzed samples was 722.4 and 27.136 mg/kg respectively during the past 3 years.

Herbal distillates have been used for many centuries as drinks, flavors, and herbal medicine in Iran, especially in the city of Urmia. Recently, some studies claimed the presence of methanol in different types of herbal distillates. Methanol is a highly toxic compound which can cause acute or chronic toxicity in humans. Acute poisoning with methanol can cause different complications and even death while chronic methanol exposure has a wide range of nonspecific and misleading findings. The main purpose of this study was to determine methanol content in the commonly-used industrial herbal distillates produced in Urmia. Five samples of six types of most commonly used herbal distillates (peppermint, musk willow, lemon balm, pennyroyal, dill, and rose water) were purchased from five active herbal distillates manufacturers in Urmia. All samples were transferred to the laboratory and methanol content of each sample was measured two times according to the standard method of analysis using spectrophotometer. The lowest and highest concentration of methanol were found in rose water (mean=72.4±32.1 ppm) and musk willow (mean=278.3±106 ppm) samples, respectively. One-way ANOVA showed statistically significant differences among methanol concentrations in the studied herbal distillates (F=60.9, P <0.001). Different amounts of methanol were found in herbal distillates and it seems that there are statistically significant differences in methanol concentrations of various types of herbal distillates. Therefore, considering the harmful effects of methanol on human health, further studies are required for determining permitted levels of methanol in herbal distillates.