ABSTRACT

        Background and Objective: Microalgae are a group of algae that produce biochemical products consisting of a wide range of carbohydrates, lipids and proteins that are commercially valuable. Interest in microalgal cultivation is currently blossoming globally. Species of Dunaliella are found in freshwater, euryhaline habitats of all continents, oceans including the Dead Sea and even the salt lakes of the Antarctic. This study investigates the effect of different salinity levels on β-carotene production by Dunaliella sp.

       Methods: Water samples from a hyper-saline lake (the Maharlu Lake in Shiraz) were cultured in modified Johnson media. The β-carotene content was measured after the samples were treated with different salinities (1, 2 and 3M NaCl).

         Results: The cell count and β-carotene content of Dunaliella sp. samples ranged between 0.46×10⁶ to 2.12×10⁶ cell.mL^-1 and 0.15 to 9.98 pg.cell^-1, respectively. At the end of the experiments, the mean maximum cell content (1.78×10⁶ cell. mL^-1) and the highest mean β-carotene content (7.41 pg. cell^-1) were obtained at 2 and 3M NaCl concentrations, respectively.

       Conclusion: Salinity of the medium might affect the quantity and composition of carotenoids in Dunaliella sp. isolates. Alteration of the culture medium’s salinity to 3M NaCl significantly increases the accumulation of β-carotene and total carotenoids in Dunaliella sp. isolates.

       Keywords: Dunaliella, Microalgae, Maharlu Lake, β-carotene.

ABSTRACT
       Background and objectives: Contamination of food products with mycotoxins is a public health problem. The International Agency for Research on Cancer has identified mycotoxins as hepatotoxic and carcinogenic agents to humans (Group 1). The Kurdistan Province is the ninth largest producer of wheat in Iran. We aimed to determine the level of contamination with total aflatoxin (TAF), aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) in 66 wheat samples randomly selected from 11 wheat flour factories in spring and summer.
       Methods: The level of toxins was measured by microtiter plate enzyme-linked immunosorbent assay (ELISA) using a microtitre plate ELISA reader and total AF, AFB₁ and OTA commercial kits.
      Results: Overall, the level of TAF and AFB in 16.67% of the samples exceeded the maximum tolerable limit set by the Institute of Standard and Industrial Research of Iran (ISIRI). However, the level of OTA contamination did not exceed the maximum tolerable limit set by the ISIRI. In addition, the level of TAF, AFB₁ and OTA exceeded the maximum tolerable limit set by the EU in 68.18, 90.91 and 36.36% of the samples, respectively. The level of contamination with these mycotoxins differed significantly in spring and summer (P<0.05).
      Conclusion: The level of mycotoxin contamination in wheat samples produced in the Kurdistan Province is alarmingly high and appropriate measures should be taken to eliminate the causes of this issue.
         KEYWORDS: Aflatoxin, Aflatoxin B_1, Ochratoxin A, Wheat, ELISA.

ABSTRACT
           Background and Objectives: Local cheese made from raw milk is one of the most commonly consumed dairy products in the world. Mycotoxin contamination of foodstuff and its transmission to consumers are extremely important public health issues. The purpose of this survey was to determine the level of aflatoxin M1 (AFM1) residues in Koupeh cheese, a traditional fermented Iranian cheese produced in spring and summer.
           Methods: We randomly collected 48 local cheese samples produced in Mahabad (northwest of Iran) during spring and summer. The level of AFM1 was measured by enzyme-linked immunosorbant assay using commercial kits and a microplate reader.
           Results: All samples contained measurable amounts of AFM1. Cow milk cheese samples contained higher level of AFM1 compared to sheep milk cheese samples. The level of AFM1 in the samples from both animals was lower in summer. There was no significant difference between the mean level of AFM1 in summer and spring. Moreover, 33.3% of cow milk cheese samples collected in spring and 16.6% of the samples collected in summer contained toxin levels higher than the maximum allowed concentration set by the European Commission (250 ng/Kg) and by the Institute of Standards and Industrial Research of Iran (200 ng/Kg).
           Conclusion: The results of this study show that the level of AFM1in Koupeh cheese is influenced by the livestock type and production season, in a way that the level of contamination is higher in spring.
           Keywords: Cheese, Cultured Milk Products, Aflatoxin M1, ELISA.