A region of heterogeneity adjacent to the 5s ribosomal RNA gene of cereal rusts

Summary Total genomic DNA was isolated from three cereal stem rusts, Puccinia graminis f. sp. tritici, f. sp. secalis, f. sp. avenae, and two cereal leaf rusts, P. recondita f. sp. tritici and P. coronata f. sp. avenae, and analyzed for the presence of heterogeneity in the intergenic region of the ribosomal DNA repeat unit. A 1 kb region of the repeat unit between the 26s and the 5s rRNA genes (IGR-1) was amplified by PCR and was found to be heterogeneous within each isolate and variable in size between races and species. The PCR results were confirmed by Southern blot analysis of native DNA. In an isolate of race C36(48), heterogeneity appeared to be due to variable numbers of 0.1 kb subrepeats in IGR-1. Nine wheat stem rust strains representing nine different races produced a unique pattern of heterogeneity while two different isolates of one race were identical, as were five of another. This may provide a rapid method for race identification in wheat stem rust. Heterogeneity and polymorphism in rye stem rust, oat stem rust, wheat leaf rust, and oat crown rust, was less pronounced than in wheat stem rust. In the course of this work, the 5s rRNA gene was located and its position and orientation within the ribosomal repeat unit was established.     

Rapid determination of benzophenone derivatives in cereals using FaPEx coupled with ultra–high-performance liquid chromatography–tandem mass spectrometry

A robust and sensitive analytical method was developed and validated for the simultaneous analysis of the levels of 10 benzophenone derivatives (BPs; BP, BP-1, BP-2, BP-3, BP-8, 2-hydroxybenzophenone [2-OHBP], 4-hydroxybenzophenone [4-OHBP], 4-methylbenzophenone [4-MBP], methyl-2-benzoylbenzoate [M2BB], and 4-benzoylbiphenyl [PBZ]) in 54 breakfast cereal samples. A fast pesticide extraction (FaPEx) technique coupled with isotope-labeled internal standards ultra–high-performance liquid chromatography–tandem mass spectrometry was employed. The developed method exhibited satisfactory linearity (R² > 0.998), high precision (intraday and interday relative standard deviations in the ranges of 1.4%–20.8% and 3.2%–23.9%, respectively), and a limit of detection ranging from 0.001 to 0.122 ng/g. BP and 4-MBP were detected in all samples, BP-3 was detected in >59% of the samples, M2BB was detected in 14% of the samples, and 4-OHBP was detected in 7% of the samples. The mean level (range) of BP was significantly higher in corn flakes [146.9 (25.3–1083.8) ng/g] than in oatmeal [22.8 (14.2–67.5) ng/g], and it contributed the most to the overall levels of the BPs, followed by 4-MBP. When the samples were stratified according to their packaging material, the mean level of BP was significantly higher in corn flake samples with plastic packaging (251.9 ng/g) than in corn flake and oatmeal samples with laminated aluminum foil packaging. Two samples of six-grain muesli contained remarkably high levels of BP (1084 and 1055 ng/g); both were nonorganic samples packaged in a polylactide bag. Future studies must examine the possible risks that these contaminants pose to human health.     

Fumonisins and deoxynivalenol in corn-based food products in Portugal

A great diversity of crops is vulnerable to fungal attack and might be contaminated with mycotoxins. Currently it is estimated that 25% of the world's harvest production is contaminated to some level with these toxins. The presence of fumonisins and deoxynivalenol in corn-based foods, available in Portugal, was analyzed in order to produce some data that may be useful for hazard characterization. A total of 105 samples were screened, including, corn meal (41), sweet corn (49) and corn flakes (15). None of the 15 samples of corn flakes contained some detectable amount of fumonisins. However, fumonisin B1 (FB1) and fumonisin B2 (FB2) contamination was found in 100.0% and 70.7% of the corn meal samples, respectively. Sweet corn samples were positive in 73.4% for FB1, although no FB2 was detected. The highest levels of fumonisin were found in corn meal (maximum: 1300 microg FB1/kg and 450 microg FB2/kg). The presence of deoxynivalenol was not detected in any of the analyzed samples. Nevertheless these results indicate the need to establish, by corn products manufacturers, a continuous monitoring program to prevent and manage the occurrence of these contaminants.     

Effects of γ-radiation on the fungus Alternaria alternata in artificially inoculated cereal samples

The objective of this study was to evaluate the effects of different γ-radiation doses on the growth of Alternaria alternata in artificially inoculated cereal samples. Seeds and grains were divided into four groups: Control Group (not irradiated), and Groups 1, 2 and 3, inoculated with an A. alternata spore suspension (1×10⁶ spores/mL) and exposed to 2, 5 and 10 kGy, respectively. Serial dilutions of the samples were prepared and seeded on DRBC (dichloran rose bengal chloramphenicol agar) and DCMA (dichloran chloramphenicol malt extract agar) media, after which the number of colony-forming units per gram was determined in each group. In addition, fungal morphology after irradiation was analyzed by scanning electron microscopy (SEM). The results showed that ionizing radiation at a dose of 5 kGy was effective in reducing the growth of A. alternata. However, a dose of 10 kGy was necessary to inhibit fungal growth completely. SEM made it possible to visualize structural alterations induced by the different γ-radiation doses used.     

Health risk assessment of heavy metals via dietary intake of foodstuffs from the wastewater irrigated site of a dry tropical area of India

The present study was conducted to assess the risk to human health by heavy metals (Cd, Cu, Pb, Zn, Ni and Cr) through the intake of locally grown vegetables, cereal crops and milk from wastewater irrigated site. Milk is not directly contaminated due to wastewater irrigation, but is an important route of food chain transfer of heavy metals from grass to animals. Heavy metal concentrations were several fold higher in all the collected samples from wastewater irrigated site compared to clean water irrigated ones. Cd, Pb and Ni concentrations were above the ‘safe’ limits of Indian and WHO/FAO standards in all the vegetables and cereals, but within the permissible limits in milk samples. The higher values of metal pollution index and health risk index indicated heavy metal contamination in the wastewater irrigated site that presented a significant threat of negative impact on human health. Rice and wheat grains contained less heavy metals as compared to the vegetables, but health risk was greater due to higher contribution of cereals in the diet. The study suggests that wastewater irrigation led to accumulation of heavy metals in food stuff causing potential health risks to consumers.     

Glycemic index of cereals and tubers produced in China

AIM: To determine the GI of some cereals and tubers produced in China in an effort to establish the database of glycemic index (GI) of Chinese food. METHODS: Food containing 50 g carbohydrate was consumed by 8-12 healthy adults after they have been fasted for 10 h and blood glucose was monitored for 2 h. Glucose was used as reference food. GI of food was calculated according to a standard method. RESULTS: GI of 9 types of sugar and 60 kinds of food were determined. CONCLUSION: Food GI is mainly determined by nature of carbohydrate and procession. Most of cereals and tubers produced in China have similar GI with their counterparts produced in other countries.     

Studies on the extraction and purification of phytic acid from rice bran

The objective of this work was to develop rice bran IRGA 417 phytic acid (PA) extraction and purification techniques. For the extraction of PA, a complete 2⁴ factorial design with triplicates at the central point was used, and the effects of concentration of rice bran and HCl, time and temperature were investigated. During purification, different pH values were tested with addition of 1.5 M Na₂CO₃ or 4.0 M NaOH. The results obtained by the statistical analysis of the factorial design showed that temperature, time and HCl concentration influenced the PA extraction technique significantly (p ≤ 0.05), whereas the concentration of rice bran had no influence. The content of PA was evaluated in all the stages of purification and it was possible to establish an improved methodology of extraction and purification with high purity and yields.     

低硒大骨节病区粮对大鼠软骨胶原可溶性的影响

本文应用低硒大骨节病区粮、病区粮加硒和非病区粮饲料喂养三组大鼠,目的观察低硒大骨节病区粮和硒对软骨胶原可溶性的影响。结果表明,低硒大骨节病区粮可导致大鼠软骨胶原可溶性胶原含量降低,提示胶原合成速率下降。加硒后部分可溶性胶原含量增高。低硒大骨节病区粮对大鼠软骨胶原可溶性的影响与机体硒缺乏和血清VC含量降低有关。     

Interaction of Microbiome,Diet, and Hospitalizations Between Brazilian and American Patients With Cirrhosis

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