جستجوی مقالات مرتبط با کلیدواژه "ذرت" در نشریات گروه "پزشکی"

Water crisis in many regions of the world especially arid and semi-arid areas such as Iran, is an important obstacle for socioeconomic development and food security. Under such circumstances, wastewater reuse in agriculture can be regarded an important alternative water source. However, treated wastewater may contain some types of pathogenic microorganisms which can threaten human health. In the present study we compared the impacts of treated wastewater (TWW) and tap water irrigation on microbiological quality of soil and crops (maize and maize leaves) through a furrow irrigation system in an experimental field.

Total and fecal coliforms and Escherichia coli were monitored as indicator bacteria in TWW, irrigated soil and harvested maize and maize leaves. We investigated the presence of Salmonella and Shigella by using a combination of culture and molecular methods. Statistical analyses were performed by SPSS 22.0 software. P<0.05 was considered statistically significant. The Mann-Whitney test was used to evaluate the difference of microbial parameters in the plots irrigated with the two types of water.

The microbiological quality of wastewater in terms of mean concentration of E. coli (3.5 Log MPN/100 ml) was compatible with that recommended by the world health organization (WHO) for irrigation of fast-growing crops (≤ 105 E. coli per 100 ml). Although, the microbiological quality of soil was affected by TWW irrigation (p < 0.05), a relatively low concentration of E. coli was detected in soil. Harvested maize had no microbial contamination with E. coli. However, one sample of wastewater-irrigated maize leaves was contaminated with E. coli. The TWW, soil and crop samples were not positive for pathogenic bacteria.

According to the results, TWW could be used as an alternative source for irrigation of maize.

Today, the consumption of frozen fruits and vegetables has been increasing due to the ability of these products to persuade the consumers to maintain nutritional value, time-saving and other practical reasons. The aim of this study was to investigate some physicochemical properties of two groups of corn kernels, single and attached to the cob, after heat processing and storage at -18 ° C. In this study, sweet corn in two forms of single kernels and corns on the cob were cooked for 4, 8 and 12 minutes and stored for 10 weeks at -18 ° C. The
effects of heat treatment on the drip loss, color changes, total phenolic content, antioxidant activity, peroxidase activity, hardness and microstructure were investigated every two weeks. The amount of drip loss increased significantly (p<0.05) during freezing, and therefore the hardness decreased, in which the corns on the cob were more effective in maintaining their water structure as compared to the single kernels. The peroxidase activity, total phenolic content and antioxidant activity were significantly (p<0.05) decreased with heating process. The reversibility of peroxidase activity was observed during the freezing storage. In terms of the radical scavenging capacity, there was no significant difference between single corns and the ones on the cob. The amount of phenolic compounds increased until the fourth week and then decreased significantly (p<0.05) during storage at -18 °C. Moreover, the corns on the cob also showed more color changes than the single ones. Heat Treatment has significant effect on some physicochemical properties of corn during storage at -18 ° C

Lead is a dangerous heavy metal for human health. This research was conducted to study the potential of a new Iranian corn (Maxima CV.) and white clover in monoculture and mixed culture for phytoremediation of Pb in a Pb polluted soil.
The experimental treatments consisted of corn and white clover in a mixed culture (with 10 and 20 plant density) and either corn or white clover in a monoculture system (with 10 and 20 plant density) in a Pb polluted soil (800 mg Pb (kg soil)-1) at 60 and 90 days of experiment. Plant and soil Pb concentration were measured using atomic absorption spectroscopy.
Root and shoot Pb concentration of corn and white clover were significantly increased in a mixed culture system relative to mono culture system. In addition, the increase of white clover density from 10 to 20 in a mixed culture system caused a significant increased Pb concentration in root and shoot of corn and white clover. The highest Pb translocation factor (TF) and shoot Pb concentration were observed in white clover in a mixed culture of corn and white clover (with 20 plants density).
The results of this study showed that the Pb concentration of corns shoot in a mixed culture system with corn and white clover (20 densities) was three times higher than that of the monoculture system.

Fusarium species are prevalent contaminants of foodstuffs and agricultural crops. They produce fumonisins، which are carcinogenic mycotoxins. The present study has evaluated maize and wheat samples from ten provinces in Iran that were contaminated with Fusarium species. Special attention was paid to the ability of the isolates to produce fumonisin B1 (FB1) as a public health hazard. We collected 32 maize and 15 wheat samples from ten provinces that were major cultivation areas. Samples surface disinfected with a 1% sodium hypochlorite solution for 2 minutes. Fusarium species were isolated by the flotation method on malachite green agar. Pure cultures on potato dextrose agar (PDA) were identified using a combination of macroscopic and microscopic morphological criteria. The ability of the isolates to produce FB1 was evaluated by thin layer chromatography (TLC) and the amounts of fumonisin B1 produced were assessed by high performance liquid chromatography (HPLC). A total of 55 Fusarium isolates that belonged to five species were isolated. There were 27 of the 32 maize samples (84. 4%) and 11 of 15 wheat samples (73. 3%) that were contaminated with Fusarium species. Species consisted of F. verticillioides (23 isolates)، F. proliferatum (22 isolates)، F. subglutinans (5 isolates)، F. nygamai (4 isolates) and F. redolens (1 isolate) based on morphological criteria. Twenty-two of the 55 (40%) Fusarium isolates produced FB1 in a total range from 230. 4 to 9565 µg/ml. The highest amounts of FB1 production were related to toxigenic isolates of F. verticillioides and F. proliferatum. Results of the present work indicates a high degree of contamination of maize and wheat with Fusarium strains that belong to the Gibberella fujikuroi species complex وparticularly F. verticillioides and F. proliferatum. This contamination is a potential public health threat due to food spoilage and subsequent production of high levels of carcinogenic FB1.

In recent decade، phytoremediation technology is regarded very important because of its simplicity، inexpensiveness and use of natural resources and solar energy. In this study، we investigated the efficiency of remediation of contaminated soil with Lead and Cadmium by using native plants of Iran. We selected three native plants of Iran (Abutilon theophrasti، Amaranthus retoflexus and Zea maize) for this study. Extraction of soil and plant samples was performed by use of HNO3، HCl and HNO3، HClO4 and H2SO4 respectively. Concentrations of Lead and Cadmium in soil and plants were determined by Perkin-Elmer 603 atomic absorption spectrophotometer. Lead concentration in the roots of plants (Alkaline soil) was more than those in their shoots. In acidic soil (with exception of Zea maize)، concentration of Lead in the shoots was more than its concentration in the roots of the plants. Concentrations of lead in the roots and shoots of Abutilon theophrasti، Amaranths and Zea maize in alkaline soil were (54. 5 and 25. 5 mg/kg)، (69 and 37. 6mg/kg) and (47 and 32mg/kg) respectively، and its respective concentrations in acidic soil were (71. 4 and 92. 5 mg/kg)، (89 and 120. 5mg/kg) and (85 and 66. 7 mg/kg). Cadmium concentrations in alkaline soil were (6. 5 and 4mg/kg)، (8 and 6. 2 mg/kg) and (5. 6 and 3. 4 mg/kg) and in acidic soil were (5. 8 and 4. 5 mg/kg)، (7. 6 and 5. 4mg/ kg) and (6 and 4. 8 mg/kg) respectively. Plants in group 3 produced less biomass than those in control group، group 1 and group 2. Considering the increased rate of absorption of Lead and Cadmium and the amount of biomass produced by Zea maize and Amaranthus retoflexus in the acidic and alkaline soil، use of these native plants is recommended for refining the soil contaminated with heavy metals.