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Aflatoxin M­1 is a result fungal secondary metabolite in ruminants .this toxin remains in milk as one the most important contaminants. In this work we modified the methods described by other researchers and presented it as a validated method for monitoring aflatoxin M1 in Iranian white cheese for the first time. At first, toxin was extracted from a polar solution (dichloromethane) and then the extract was dried and dissolved in hexan, methanol and water solution .in the third step water phase separated and purified using immunoaffinity liquid chromatography .for method validation we calculated accuracy, precision and sensitivity factors. Measurement of accuracy of method was performed by fortification of conventional blank samples. For precision measurement method was evaluated in six working days under repeatability condition and calculated the mean, variance and relative standard deviation (RSD). Limit of detection in our method was 55 ppt and limit of quantification was 183 ppt.

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  The amount and composition of tocopherols and phenols, two main naturalantioxidants in olive oil, have been evaluated and analysed by HPLC  in seven different brands of  Iranian olive oil. Results showed that phenol and tocopherol amounts In Iran, because of long time and high temperature of malaxation and also type of extraction or even type of variety, polyphenols and tocopherols content of Iranian olive oil are low and were put on the category of low polyphenol olive oils and seems they don’t have nutritional value as virgin olive oil.

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Surfactin is one of the most efficient biosurfactants excreted by Bacillus subtilis which displays the highest potential as induced systemic resistance elicitor among all metabolites produced by B. subtilis. Environmental factors have considerable effect on surfactin production. In this study surfactin production of two Bacillus subtilis strains were analyzed using high performance liquid chromatography (HPLC). C14 and C15 surfactins were detected in the ethanol extract from acid-precipitated supernatant. HPLC analyses of different media including Nutrient Broth (NB) medium, NB plus 40g/l glucose, NB plus 10% soil extract and NB plus 10% plant extract medium, clearly showed that these bacteria produced different amounts of surfactins C14 and C15 in these media. Surfactin production in NB/plant medium was relatively the highest in quantity. Microelements analysis of media containing plant and soil extract with atomic absorption spectrometry showed high amounts of Fe, Mn and Zn in medium containing plant extract compared with that of soil extract. Since these elements play an important role in surfactin production, high amounts of Fe, Mn and Zn in NB/plant extract medium compared to the NB/soil extract medium could be the possible reason for relatively higher amounts of surfactins C14 and C15 produced in NB/plant medium. So adding these important elements to soil may boost biocontrol effect of B. subtilis against plant pathogens.

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Aim: Cereals and cereal-based products are prone to be infected by mycotoxin-producing fungi. The aim of this study was to investigate the level of contamination caused by 11 major mycotoxins in wheat samples collected from wheat silos in Tehran and Alborz provinces using UHPLC-MS/MS device.
Materials & Methods: Samples preparation was performed based on the extraction and purification procedures using acetonitrile/water/acetic acid solvents and Myco6in1 immunoaffinity columns, respectively. Selected mycotoxins were detected simultaneously using reversed phase ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) with electrospray ionization technique in positive-ion mode in a 15-minute run in the MRM program. Spiked samples calibration curve was used to overcome the matrix effects and to determine the residual mycotoxins.
Findings: Quantification and detection limits for AFB1 and OTA mycotoxins were 2 and 0.7 ppb; for DON, FB1, and FB2 were 100 and 33.3 ppb; for ZER were 50 and 16.6 ppb: for AFB2, AFG1, AFG2, and T-2 were 5 and 1.6 ppb; and for HT-2 were 20 and 6.6 ppb, respectively. Good precision and linearity was observed for mycotoxins. The average recovery rate of mycotoxins was in the range of 72-123 %, and the relative standard deviation (RSDr), indicating the method accuracy, was between 0.6-24.2 %. The validated method for analyzing the 30 wheat samples was used to evaluate the residual mycotoxins. OTA, T-2, and HT-2 mycotoxins were found in wheat samples. Only in one sample, the level of residual OTA exceeded the allowable limit set by the Iranian National Standards Organization.
Conclusion: The present study results highlighted the need for monitoring wheat and wheat-based products and the implementation of control and preventive measures in wheat fields, storage warehouses, and flour factories.

 

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Aspergillus flavus is a saprophytic fungus contaminating different food and nut products by aflatoxin which is a major problem worldwide. Modified atmosphere packaging (MAP) could be an effective method for control of saprophytic fungi and their toxins and secondary metabolites production. This study gives the consequences of fungal isolates growing under MAP condition on potato dextrose agar (PDA). Two isolates of A. flavus (A42 and CHAO50) were packed under 100% CO₂, 100% O₂ and vacuum conditions. The mycelial growth of fungal isolates on PDA was controlled up to 80% with CO₂ treatment. Under the vacuum condition, mycelial growth of the isolates was inhibited up to 30%, while 100% oxygen had no inhibition on mycelial growth. Examination of isolates A42 and CHAO50 under UV light showed that both isolates produced yellow pigments on aflatoxin producing ability (APA) medium after 10 days. The levels of aflatoxin B₁, B₂, G₁, G₂ and total aflatoxin were analyzed chromatographically. The results revealed that the highest concentration of total aflatoxin was produced by fungal isolates grown in an atmosphere of 100% O₂, while the level of aflatoxins was significantly reduced in 100% CO₂. 

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The allelopathic potential of the foliage tissues of eight barley cultivars was investigated using seedlings bioassays of Indian brown mustard (Brassica juncea) and green foxtail (Setaria viridis) as typical broadleaf and grass weeds of the croplands. The correlations of allelochemical compounds with seed germination of weeds were determined. The barley cultivars used were Jackson, Bronco, CDC Dolly, B1602, Harrington, UNA80, Stander, and TR251. Three dilutions of the extracts of each barley cultivar (20, 10 and 5 g/L) plus deionized distilled water, as a control, were assayed on the target weeds. The effects of barley cultivars and extract concentrations on seed germination and radicle and shoot lengths of the target weed seeds were highly significant (P<0.001). By increasing the con-centration of the allelopathic extracts, the percent germination, radicle and shoot lengths of both target plants seedlings decreased. Seed germination and seedling growth of B. juncea were more sensitive than those of S. viridis. Relative to the germination inhibition of target weed seeds in comparison to the untreated control, the selected barley cultivars were categorized as being highly allelopathic, moderately allelopathic and of low allelo-pathic potential. Among the phenolic compounds detected, the cumulative effect of four small-quantity-compounds (vanillic, chlorogenic, p-coumaric, and ferulic acids) on aver-age weed germination was very high (R2 = 0.83), with B. juncea it was high (R2 = 0.70) and with S. viridis it was very low (R2 = 0.15). The two high concentration phenolic compounds of protocatechuic and p-hydroxybenzoic acid, when accumulated with the small-quantity phenolic compounds of barley cultivars, reduced the weed seeds germination correlation to r=- 0.11.

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Deoxynivalenol contamination was determined in corn produced in Golestan and Ardabil (Moqan) Provinces, Iran, in 2004-2005. Samples were collected from different stages of production, including before harvest, at harvest, post harvest as well as after drying. Ground sub samples were extracted with water; each extracted sample was cleaned up through an immunoaffinity column. Deoxynivalenol was estimated through reversed-phase High Performance Liquid Chromatography (HPLC). The linearity of standard curve for 50 -10,000 ng ml-1 of standard solutions was proved (R2= 0.9999). Detection limit was 10 ng g-1. Recovery of the method for 1,000 and 500 ng g-1 spiked samples was 73.5% and 93.5% (n= 5). Deoxynivalenol contamination was found in 76.7% of samples in the range of 54.4-518.4 ng g-1. The mean of contamination was 116.25 ng g-1. This is the first report of natural DON contamination of corn from Iran.

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Objective: With consideration of lethal effects of aflatoxins specially B1 on human health. Estimation of aflatoxin-albumin adduct, as an important marker of aflatoxin exposure, seems essential. The aim of this study is optimization of HPLC-fluorescence method for measurement of this important marker in blood serum. Materials and Methods: In this study, blood serum of three groups of rats as A) positive controls (treated with AFB1), B) negative controls (without treatment) and standard rats (treated with radiolabeled AFB1) were used. After albumin isolation using ammunium sulphate and acetic acid, purity of albumin was tested by SDS-PAGE electrophoresis and albumin concentration was quantified by bradford method. Then albumin was hydrolysed by pronase and aflatoxin bound to albumin was released as aflatoxin-lysine. Pronase was precipitated and albumin was digested by aceton in cold, the volume of supernatant was reduced by freeze-drier and injected into HPLC system. Aflatoxin was quantified in comparison to standard rats samples. Results: The purity of this isolated albumin was confirmed by SDS-PAGE electrophoresis. Albumin concentration in positive, negative and standard samples were 10, 13 and 12.5 mg/ml, respectively. Detection limit (20 pg/mg Alb) for measurement of aflatoxin was determined by HPLC method, specificity and sensitivity of method were 92% and 100% respectively. The mean concentration of AF-Alb adducts in serum of positive control rats was 10 ng/mg Alb and the reproducibility of the method after several repeat was very good. Conclusion: In this study, for AF-Alb adduct quantification by HPLC method, mobile phase, percentage of solvents and run time were changed and the affinity chromatography before HPLC, was deleted. Therefor HPLC- fluorescence which is a precise and specific method, and since it is fast, highly reproducible and cost effective, also with improvement made, could easily be used for the quantification of this important marker in serum.

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Major data about antibiotic residues in food limited to raw material. Because food was cooked before consumption, it’s necessary to assess effect of heat treatment on antibiotic residues. The goal of this study is to evaluate effect of frying on tylosin residue in meat. Tylosin was added in three levels  4, 8 and 16 µg to 20 g minced meat samples and they were fried at 180 ^oC during 3, 5 and 7 min. Tylosim amount was measured before and after frying by HPLC and tylosin reduction percent, samples center temperature and their weight reduction percent were determined after frying. In all treatments tylosin in fried samples was significantly less than raw samples (p< 0.05). Tylosin reduction (%)amount had significant and positive correlation with frying time, sample weight percent and center temperature. By increasing frying time, weight and tylosin lost and center temperature reductions have been increased. Although frying resulted in tylosin residue reduction in meat, it isn’t grantee for this goal therefore it is necessary to reduce tylosin residue in meat by its correct consumption in animals and withdrawal period consideration.  

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In present study, dried pomegranate peel of three dominant Iranian varieties was extracted by soxhlet extraction (SE) method via four solvents. In this study Five anthocyanins were identified and quantified in the extracts by high performance liquid chromatography (HPLC) coupled with ultraviolet-visible (UV-Vis) spectrometric detector at wavelength of 517 nm according to their retention times and external standard method. According to the results extraction yield of Poost Siyahe Shirine Ardestan (PSSA) variety is more than other two varieties and extraction yield of ethanolic extracts is more than other solvents in p≤0.05. HPLC analysis was indicated pomegranate peel include of more mono glucoside anthocyanins than di glucoside anthocyanins also the most of anthocyanins particularly mono glucoside anthocyanins were detected in ethanolic extract obtained from dried peel of PSSA variety.    

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Objective: Saffron is the dried stigmas of Crocus sativus L. which has various therapeutic properties in addition to its use as a spice. More than 80% of the world present production of saffron which is about 190 tons is produced in Iran. To compare the quality of saffron' from different parts of the world, researcher used one sample from each country. Since cultivation of saffron is done in different geographical areas of Iran, it seems that the results of these studies, using only one sample of Iranian saffron, are not consistent with the scientific and statistical rules. More over the results of therapeutical studies using saffron extracts from different sources with different concentrations of effective elements would not give reproducible results. As an affirmative reason, here we compared the saffron’s important components, crocin, picrocrocin and safranal, from different packages produced by some companies. Materials and Methods: Five certified saffron packages, prepared by different companies named: Ehteshamiyeh, Tarvand, Abbaszadeh, Sabagh and Novin-Saffron were analyzed using HPLC with an UV/Vis detector. To avoid the conflict of inerest, these samples were randomly labeled as 1 to 5. Results: Results indicated that all of the samples contained these ingredients at the standard levels, but the highest level of crocin as a carotenoid was seen in the sample 3, and sample 1 and 2 contained the highest concentrations of monoterpene aldehydes, picrocrocin and safranal, respectively. Conclusion: According to the obtained results and the vast area under the saffron cultivation with various climates, it is confirmed that one sample of saffron is not a measure of all of the Iranian saffron. Our research is continuing.

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The hawthorn fruits have been used as food and medicine for centuries. In the present study, pulp and seed extract of Crataegus elbursensis Rech. F. fruits belonging to the family Rosaceae and native of northern part of Iran were evaluated for the polyphenol contents, antiradical, antioxidant, and antibacterial activities. The total phenolic, flavonoid, and anthocyanin contents of methanolic pulp extract were found to be more than those of methanolic seed extract. The DPPH radical scavenging, iron (III) reducing capacity, and total antioxidant activity of the extracts depended on concentration. A 200 μg ml^-1 of C. elbursensis pulp and seed extract and butylated hydroxytoluene (BHT) exhibited 82.13, 83.47, and 85.44% inhibition, respectively. However, effect of the extracts in the total antioxidant activity and reducing power were not significantly as good as BHT. In addition, the results showed that both pulp and seed extract had inhibitory activity against the four bacteria tested, with the pulp extract showing more activity than the seed extract. Also, phenolic acids were identified by RP-HPLC and chlorogenic acid was the predominant phenolics in the samples. In conclusion, our results showed that C. elbursensis pulp and seed extract had strong antioxidant and antibacterial activities, which were correlated with its high level of polyphenols.

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Ginger (Zingiber officinale Roscoe) contains the biological properties of the major standard non–volatile pungent compounds of ginger, namely, [6]–, [8]–, and [10]–gingerols, as well as [6]– , [8]–, and [10]–shogaols. So far, the comparative antioxidant potencies among shogaols and gingerols have not been studied in detail and reported. Accordingly, this study aimed to examine and compare the antioxidant abilities of the six main compounds. Results showed that[6]–, [8]–, and [10]–gingerols, as well as [6]–, [8]–, and [10]–shogaols exhibited substantial in vitro antioxidant activities. The DPPH^•, ABTS^•+,and FRAP assays results showed that the antioxidant abilities of [6]–shogaol were greatest among the six gingerols and shogaols studied (P< 0.05), and those of [6]–, [8]–, and [10]–shogaols were greater than those of [6]–, [8]–, and [10]–gingerols, respectively, which can be attributed to the presence of α, β–unsaturated ketones moieties. Moreover, the observation that the antioxidant abilities of [6]–gingerol were greater than those of [8]– and [10]–gingerols (P< 0.05) indicated that the short carbon chains of [6]–gingerol and [6]–shogaol played a significant role in making them more potent antioxidants than the other four longer carbon chain compounds. This finding can be attributed to gingerols undergoing dehydration transformations into shogaols during oven drying. Our results provided some new information on the antioxidant abilities of gingerols and shogaols.

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The aim of the study was to evaluate changes of sorbitol, glucose, fructose, sucrose, and total sugars of plum fruits in different years under different climatic conditions i.e. air temperature and precipitation. The cultivars investigated in the research were: Topstar, Toptaste, Jojo, Haganta, Tophit, and Top 2000. The fruits were harvested at optimal stage of maturity in the experimental orchard of the Agricultural Institute Osijek. Content of glucose, fructose, sucrose, and sorbitol in the fruits were identified and quantified by high performance liquid chromatography (HPLC). Significant differences were found between sucrose, glucose, fructose, and sorbitol depending on climatic conditions and cultivar. Sucrose was the highest in almost all years. Glucose was the predominant sugar in cultivars Jojo and Top 2000. Fructose and sorbitol contents were lower than sucrose and glucose. Average sugar contents in 2008-2012 period were compared with respect to climatic conditions. A significant effect of year was found for sucrose, sorbitol, total sugar, and dry matter, whereas no effect was found for glucose and fructose contents. Individual sugar contents correlated significantly with each other. The principal component analysis (PCA) showed that plum cultivars were clearly differentiated according to variability of sugar in fruit caused by climatic conditions. The obtained results highlighted that climatic conditions may have significant effect on plum fruit quality and, therefore, it is important to have adequate testing before recommending a cultivar for planting. 

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Food safety is a global concern due to an increasing awareness of consumers concerning exposure of foods to chemicals and contamination with such hazardous biochemicals as dioxins, mycotoxins, pesticides, polycyclic aromatic hydrocarbons, drugs and hormones. Patulin is one of the most injurious mycotoxins produced by a variety of molds, particularly Aspergillus and Penicillium species. Based on valid international standards, a maximum permitted level of patulin is 50 µg L^-1 in fruit products. In the present study, patulin content of seventy two apple juice samples from West Azerbayjan Province of Iran was determined through High Performance Liquid Chromatography (HPLC). Results revealed the contamination of all the analyzed samples with toxin at a mean content of 48.64 µg L^-1. Almost 29% of samples were contaminated with a dose more than 50 µg L^-1 of patulin. Implementation of appropriate agricultural, as well as, technical practices in apple juice preparation factories of the region is recommended, in order to decrease the contamination level and its deleterious risks.

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Antibiotic residues in meat and other foods of animal origin have adverse effects on consumer health. In this study, first, penicillin residues of 45 samples (15 meat samples, 15 liver samples and 15 kidney samples) randomly collected from Tehran retailers were evaluated by ELISA method. Based on ELISA results, from total 45 samples, 43 cases were diagnosed as contaminated sample for antibiotic residues. The highest penicillin amount was observed for liver samples but there was no significant difference between kidney and liver samples (p=0.895). Subsequently, samples with equal amounts of penicillin were removed and other samples were analyzed by high performance liquid chromatography (HPLC) regarding penicillin G, ampicillin and amoxicillin. Penicillin G had the most value among other penicillin groups followed by ampicillin and amoxicillin, respectively. Liver samples showed higher levels of penicillin groups compared to meat and kidney samples, but no significant difference was found among them. Also, there was good correlation between ELISA and HPLC results and R² of all samples was greater than 0.99. Moreover, it was demonstrated that antibiotic residues of some samples were above the maximum residue limit (MRL) stated by world standards. Obtained results show the necessity of monitoring antibiotic residues in food of animal origin by related organizations especially the institute of standards & industrial research of Iran and veterinary organization.

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Folic acid is one of the essential vitamins that deficiency of it causes congenital malformations in pregnant, especially neural tube disorders. Since the human body cannot synthesize this vitamin, enrichment process on bread that is known as one of the most widely consumed foods in the diet of our people, can be on an effective step for eliminating defects caused by vitamin’s deficiency in people. Considering the health effects of wheat bran and and the presence of folic acid in it, in this study attempts to fortify flour (with 7% wheat bran) by 100% RDI folic acid and then measuring the stability of folic acid in bread making process by HPLC method and microbiological assay. The results indicated that the microbiological assay showed higher amount than the high performance liquid chromatography method because of the ability to measure the natural folate in the samples. Also, during the bread making process, the folic acid and folate content increased during the fermentation process and then decreased by the thermal baking process. The remaining amount of folic acid and folate in the final bread showed the relatively high resistance of this vitamin in the process of Barbariʼs bread, and thus the ability of the bread fortification process to provide folic acid requirements in adults.