Alternaria toxins in Argentinean wheat,bran, and flour

Alternaria species have been reported to infect a wide variety of vegetables, fruits, and cereal crops. Wheat is one of the most consumed cereal worldwide. A sensitive HPLC-DAD methodology was applied to quantify alternariol (AOH), alternariol methyl ether (AME) and tenuazonic acid (TeA) in 65 samples of whole wheat, bran, and flour. The extraction methodology allowed extracting the three toxins simultaneously. Limits of detection in wheat were 3.4, 4.5, and 0.5 µg kg^?1 for AOH, AME and TeA, respectively. For bran, these data were 3.1, 4.5, and 12 µg kg^?1 and for flour 50, 70, and 14 µg kg^?1, respectively. The studied recoveries were higher than 70% and RSD was below 10%. Wheat and bran samples showed low AOH and AME contamination compared to TeA. The averages levels found for TeA in wheat, bran and flour were 19,190, 16,760, and 7360 µg kg^?1, respectively.     

Isolation,purification, and characterization of the globulin from wheat germ

This research optimized the extraction and purification of globulin from wheat germ and assessed the molecular weight distribution and structure properties of the globulin obtained. The results showed that the relative extraction efficiency and purity of wheat germ globulin (WGG) reached 18.0% and 89.1% under the enzymolysis conditions of 0.32‰ α-amylase, pH 6.5, and 55 °C. The maximal precipitation rate of WGG (91.3%) was obtained with pH 4.3 (acid precipitation). Additionally, the molecular weight of WGG was mainly distributed below 70 kDa. FT-IR confirmed that random coils (30.95%), β-sheet (27.02%), α-helix (26.55%), and β-turn (15.48%) were the secondary structures of WGG. Furthermore, LTQ mass spectrometry showed that WGG was rich in variety and high in complexity, which retrieved 1274 proteins belonging to 392 proteomes by inverse peptide analysis. The findings endow a great potential of preparing WGG with superior functionality for food applications.     

Deoxynivalenol and its masked forms: Characteristics,incidence, control and fate during wheat and wheat based products processing - A review

BackgroundDeoxynivalenol (DON) is a toxic secondary metabolite primarily produced by Fusarium graminearum and Fusarium culmorum that is common in grains, such as wheat and wheat-based products.Scope and approachThis review points out on the main DON-producing fungi, the factors affecting DON production, its toxicological aspects and preventive measures to avoid contamination of foods by DON. Further, the article discusses the fate of DON throughout the processing of wheat, bread, and pasta and finally critically assesses data on the impact of specific steps of processing on DON contents in wheat-based products.Key findings and conclusionsThe proposed controls at pre- and post-harvest stages seem to comprise the most efficient strategies to manage the incidence of DON in wheat and wheat-based products. Prevention of plant infection by Fusarium species, managing crops and ensuring the rapid drying of wheat after harvest is the effective approaches for the elimination of DON contamination. There has been contradictory data in the literature on the fate of DON during wheat and wheat-based products processing Due to differences in processing, such as temperature, additives, processing time and loaf size in addition to the occurrence of modified (masked) forms of DON. Therefore, further research must be carried out aiming to reveal the formation and occurrence of modified forms of DON. These compounds can be formed throughout wheat processing, from pre-harvest to processing of wheat-based products, and for proper quantification, analytical methods able to quantify modified forms of DON are required.     

Carbohydrate composition of wheat,wheat bran,sorghum and bajra with good chapati/roti (Indian flat bread) making quality

Varieties of wheat, sorghum and bajra having good chapati/roti making quality were studied for carbohydrate profile. Polysaccharide fractions (water-soluble, barium hydroxide-soluble, alkali-soluble and insoluble) were isolated from these cereals and wheat bran and their carbohydrate profiles were studied. Arabinoxylans were the major polysaccharides, other than starch and cellulose. The ratio of arabinose to xylose in whole-wheat flour and wheat bran was nearly 1.25:1 but the hemicellulose A in wheat flour was mainly xylan-type. Among the pentosans in barium hydroxide extract of sorghum, the hemicellulose A had more arabinose than xylose, but the hemicellulose B contained nearly equal amounts of arabinose and xylose. Bajra had arabinose and xylose in nearly equal amounts in both the barium hydroxide extract and alkali-soluble fractions. The alkali-insoluble residues were complexes of pentosans with cellulose and were strongly bound. Contents of dietary fibre varied between the cereals. Wheat bran had the highest among the four.     

Forecast of mycotoxins levels in soft wheat, durum wheat and maize before harvesting with Qualim��tre?

Some mycotoxins are produced by several Fusarium species during cultivation and are found in wheat and maize grain. Since 2000, Syngenta has organised a large field survey. Agronomic and climatic data and grain samples have been collected for mycotoxin analysis in France and Belgium. The importance of the agroclimatic factors and their interactions on the mycotoxin levels in grain has been estimated. The climate around flowering stage is the major factor for deoxynivalenol (DON) in wheat. The main agronomic criteria are residue management and the variety sensitivity to this mycotoxin. For DON, zearalenone and fumonisins in maize, the climate from flowering stage until harvest is the major factor. Then, according to each mycotoxin, the main agronomic criteria are the harvest condition (date and grain moisture), the corn borer infestation and the variety sensitivity to these mycotoxins. Over the years, the database has been used to define models to predict the mycotoxin risk before harvesting. Grain purchasers enter the required agronomic data via the Syngenta Internet site and define their grain purchasing areas. They also define the flowering period for wheat and corn borer infestation for maize. After calculation which integrates climatic data, the purchasers receive reports with forecasts of mycotoxin levels. Prediction is based on different agro-climatic statistical models specifically configured according to the different regions of production in France and Belgium. This approach is called Qualimètre^? and was the first service in France and Belgium to forecast the grain mycotoxin level for wheat in 2004 and maize in 2006.     

Natural occurrence of deoxynivalenol in wheat from Paraná State,Brazil and estimated daily intake by wheat products

The occurrence of deoxynivalenol (DON) was evaluated in 113 wheat samples from the northern and central/southwestern regions of Paraná State, Brazil during the 2008 and 2009 growing seasons, and this rate of occurrence was used to estimate the DON dietary exposure. The DON determination was carried out by an indirect competitive enzyme-linked immunosorbent assay. DON was detected in 66.4% samples at levels ranging from 206.3 to 4732.3 μg/kg (mean 1894.9 μg/kg). The estimated daily intake (EDI) of DON through bread and pasta was evaluated in the inhabitants of Londrina City in northern Paraná State, Brazil. The average intake of these inhabitants was 0.79 μg/kg body weight (b.w.) for bread and 0.35 μg/kg b.w. for pasta. The total EDI was 1.13 μg/kg, which is above the Provisional Tolerable Daily Maximum Intake (PTDMI) of 1 μg/kg b.w. To our knowledge, this is the first report on natural DON occurrence in wheat and DON dietary exposure estimation from Paraná, Brazil.     

Policosanol contents of beeswax,sugar cane and wheat extracts

Policosanol (PC) is a mixture of high molecular weight aliphatic primary alcohols. Currently, a number of dietary supplements containing PC are commercially available in the US market. The majority of these products are prepared from beeswax or sugar cane extracts. The main objective of this study was to compare the PC contents and compositions of beeswax, sugar cane and wheat as PC sources. The PC contents and compositions of several commercial dietary supplements were also analyzed. The precipitate formed during the cold storage of commercially hexane-extracted wheat germ oil (WGO) contained the highest total PC (628 mg/kg) among the wheat extracts and milling products examined in this study. The total PC contents of wheat straw (164 mg/kg) and sugar cane peel (270 mg/kg) were of the same order of magnitude. The total PC contents of brown beeswax were about 20 and 45 times higher than those of the WGO-solids and sugar cane peel, respectively. Commercial dietary supplements contained less total PC than were claimed on the product labels. The PC compositions of the samples analyzed in this study varied significantly with the source. Wheat can be a viable PC source for further product development or health benefits.     

Purification,crystallisation and characterisation of carboxypeptidase from wheat bran

A carboxypeptidase was purified and crystallised from wheat bran. Disc gel electrophoresis at pH 4·0 and ultracentrifugal analysis revealed that the enzyme was essentially homogeneous. The sedimentation constant and isoelectric point were determined to be 6·3 S and 6·0, respectively. The molecular weight of the enzyme was estimated to be 118,000 by a gel filtration method. The enzyme liberated carboxyl terminal amino acid residues from a wide range of N-substituted dipeptides and tripeptides which contain l-proline. It had a pH optimum at pH 4·0 for Z-Glu-Tyr (Z-benzyloxycarbonyl). The K_m and k_cat values for Z-Glu-Tyr at pH 4·0 and 30°C were 0·19 mm and 20 s^?1, respectively. The enzyme hydrolysed Z-Gly-Pro-Leu-Gly-Pro and bradykinin sequentially at pH 4·0 from their carboxyl terminal amino acid residues. The enzyme activity was completely inhibited by DFP.     

Bran characteristics and wheat performance in whole wheat bread

The effect of the composition and physical properties of bran from four wheat samples from different cultivars was determined in whole wheat bread. High specific volume of whole wheat bread was correlated (r² = 0.8275) with strong mechanical properties (low friability) of the bran of wheat cultivars, as determined by sizing (over 425 μm) of bran particles after grinding with a rotor mill. Fibre content and composition of insoluble fibre (hemicellulose, cellulose and lignin) in the bran fraction had a non‐significant (P > 0.05) effect on the performance of wheat cultivars in whole wheat bread. Water absorption of bran was correlated (r² = 0.9532) with its insoluble fibre content. Based on data obtained with white flour, it was not possible to estimate the baking potential of wheat cultivars in whole wheat bread.     

Gluten-related disorders: Celiac disease,wheat allergy,and nonceliac gluten sensitivity

Abstract

The consumption of gluten-free products is becoming an increased alimentary habit in the general population. The scientific unfounded perception suggesting that the avoidance of gluten would improve health or that gluten could be toxic for humans are fostering medically unjustified adherences to a gluten-free diet. Currently, only patients diagnosed with celiac disease are advised to follow a strict lifelong gluten-free diet. In the same way, patients diagnosed with IgE-mediated wheat allergy must avoid exposure to wheat in any form. In that context, a third disorder, called nonceliac gluten sensitivity, characterized by distress after gluten consumption and in which neither celiac disease nor IgE-mediated allergy plays a role, has gained increased attention in the last years. Although important scientific advances have been made in the understanding of the pathologic mechanisms behind nonceliac gluten sensitivity, this disorder is still a matter of active debate in the scientific community. In the present review, the most recent advances in the immunopathology, diagnostic biomarkers and susceptibility determinants of gluten-related diseases are summarized and discussed. Furthermore, an updated overview of the new potential therapies that are currently underway for the treatment of gluten-related disorders is also provided.     

Technological, rheological and yield differences among Egyptian wheat varieties

BACKGROUND: A field experiment was conducted during the two winter seasons of 2007/2008 and 2008/2009 to evaluate the yield and its components, milling, technological and rheological characteristics as well as the correlation between these characteristics of eight bread wheat ( Triticum aestivum L.) cultivars (Gemmeiza 7, Gemmeiza 9, Gemmeiza 10, Sakha 92, Sakha 93, Sakha 94, Giza 164 and Giza 168). These cultivars were chosen because they were new. RESULTS: Gemmeiza 10 was shown to have the highest number of tillers and spikes per square meter, number of grains per spike and grain yield per hectare, followed by Gemmeiza 9, Giza 168, Sakha 94, Sakha 93, Sakha 92 and Giza 164. However, Gemmeiza 7 had highest biological yield per hectare, fine and coarse bran, protein, and wet and dry gluten percentages as well as farinograph properties. Giza 168 canopies were the tallest and also the straw yield was the highest. Also, Sakha 93 surpassed the other tested varieties in harvest index, flour and carbohydrate percentages. There are highly significant and positive correlations between each of grain yield per hectare and most of its components. The correlation between each of grain yield per hectare, flour and total carbohydrate percentages and dough weakness was found to be significant and positive. However, there was a negative correlation between each of grain yield per hectare, protein, gluten and bran percentages and farinograph properties. CONCLUSION: Gemmeiza 10 cv. surpassed in yield factors and most of its components. However, Gemmeiza 7 cv. gave the highest values of grain and flour quality. On the other hand, the highest total carbohydrate and flour percentages were obtained from Sakha 93 cv. Copyright © 2010 Society of Chemical Industry     

小麦面筋蛋白的组成、结构和特性

详细介绍了小麦面筋蛋白中麦谷蛋白和醇溶蛋白的亚基组成和结构,以及各亚基与面团品质的关系。     

Phytochemical compositions, and antioxidant properties, and antiproliferative activities of wheat flour

Ten soft wheat varieties grown in Maryland were compared for their phytochemical compositions, antioxidant properties and antiproliferative activities. Free radical scavenging capacities were examined against DPPH(·), oxygen, hydroxyl and ABTS(·+) radicals. Significant radical scavenging capacities were detected in all wheat flour extracts. Total phenolic content ranged from 1.66 to 2.01 mg of GAE/g wheat flour. The wheat flours contained 172.91-297.55 μg/g insoluble bound ferulic acid, contributing 89.74-94.29% of total ferulic acid on a per weight basis. The concentrations of lutein and zeaxanthin were 0.27-0.46 and 0.08-0.13 μg/g, respectively. In addition, the wheat flours had 0.30-0.59 and 0.07-0.29 μg/g α- and δ-tocopherols, respectively. Four wheat flour extracts were further examined for their antiproliferative activities. The Jamestown wheat flour showed significant antiproliferative activity against both HT-29 and Caco-2 colon cancer cells at the initial treatment concentration of 50 mg flour equivalents/ml, while USG3555 flour showed inhibitive effect only in HT-29 cancer cells, suggesting the different and possible selective antiproliferative property of the wheat flours. These results may be used to direct the breeding effects to produce soft winter wheat varieties with improved health properties.     

Safety of Oxygreen, an ozone treatment on wheat grains. Part 2. Is there a substantial equivalence between Oxygreen-treated wheat grains and untreated wheat grains?

The Oxygreen process is a new process based on wheat grain treatment by ozone (produced in situ), in a closed sequential batch reactor. The Oxygreen process offers a close, homogeneous, and controlled contact between the gas and the grain. It is proposed for use for wheat grain decontamination (insects, fungi, bacteria, mycotoxins, pesticides). It takes place in classical milling diagram, and occurs after grain cleaning and before milling. The aim of the study reported here was to determine if Oxygreen treatment could induce in the grain the formation of processing-related compounds, and if these compounds are specific or could be recognized as classical modifications already used in the cereal industry (milling, baking). Studies were performed in order to evaluate any effect of Oxygreen treatment on vitamins, ferulic acid, phytates, proteins, carbohydrates, and lipids. It was concluded that there was no detectable substantial difference between ozone-treated grains and the untreated ones, although some quantitative differences can occur. The more detectable differences concern concentration of free sugars, and inhibition of some oxidative enzymes. These quantitative differences are very slight compared to the modifications that occur in dough, after addition of oxidative products directly in flour, or during kneading and dough fermentation.     

Determination of moisture in white flour,ground wheat and whole wheat by near infrared reflectance using a single calibration

A single calibration for the determination of moisture in white flour, ground wheat and whole wheat by near infrared (n.i.r.) reflectance analysis is presented. The predictive accuracy of the calibration compared with moisture determined by oven drying on 68 samples was 0.22%.     

小麦及其面粉品质对馒头品质的影响

综合分析了小麦与面粉的蛋白质品质、淀粉品质、酶、脂类物质等对馒头品质的影响。     

浅谈小麦不完善粒对面粉加工的影响

笔者在实践中认为,小麦不完善粒对面粉加工有着重要影响,如果能把好原粮检验这一关 ,将会对后续的生产过程得到基本有效的保障。1 小麦不完善粒的界定在国家标准GB1351—1999中,对小麦不完善粒有明确的定义。即：受到损伤但尚有食用价 值的颗粒。包括：虫蚀粒、病斑粒（含赤霉病粒和黑胚粒）破损粒、生芽粒和霉变粒。2 各种小麦不完善粒对面粉加工的影响小麦的胚部是籽粒生命活动最旺盛的部位,含有大量的蛋白质、较多的脂肪和活性强的酶 。被害虫蛀蚀后,胚乳比例减少,麦皮的比例增大,势必造成出粉率降低,面粉灰分高,面 筋质量差…