您的位置: 首页 > 院士专题 > 专题列表

共检索到620条,权限内显示50条;

[学术文献] Wheat germ agglutinin is a biomarker of whole grain content in wheat flour and pasta 进入全文

Journal of Food Science

When consumed as whole grain, wheat has a high nutrient density that contributes to a healthy diet. Yet, products labeled as whole wheat can still contain a substantial amount of refined grain leading to the confusion for consumers, so a method was designed to determine the whole grain status within wheat-based foods. Wheat germ agglutinin (WGA), a lectin found in the germ tissue of wheat kernels, was evaluated as a biomarker of whole grain wheat. WGA content strongly correlated with the percentage of whole wheat within premade mixtures of whole and refined (white) flours. Then, commercial flours labeled as whole wheat were tested for WGA content and found to contain up to 40% less WGA compared to a whole grain standard. Commercial pasta products labeled as whole wheat were also tested forWGA content and found to contain up to 90% less WGA compared to a whole grain standard. The differences in WGA content were not likely due to varietal differences alone, as the WGA content in common varieties used in domestic wheat flour production varied less than 25%. The levels of other constituents in wheat kernels, including starch, mineral, phytate, and total protein, were not different among the commercial whole wheat flours and pasta products. WGA is a unique biomarker that can identify wheat products with the highest whole grain content.

[学术文献] Transformation of Pinb-D1x to soft wheat produces hard wheat kernel texture 进入全文

Science Direct

Kernel hardness - a key quality trait of common wheat (Triticum aestivum L.) - is mainly conditioned by the Pina and Pinb genes. Mutation or deletion of Pina or Pinb increases kernel hardness, resulting in a hard wheat kernel texture. Here, Pinb-D1x gene was cloned from a hard wheat landrace Kashibaipi and transformed into a soft wheat cultivar Yangmai19 to assess its effect on kernel hardness and flour properties. PCR, RT-PCR and Western blot data confirmed the successful transformation and overexpression of Pinb-D1x gene in transgenic offsprings. The data of single kernel characterization system and scanning electron microscopy revealed that the introduction of Pinb-D1x in soft wheat increased the kernel hardness significantly and changed the internal structure of the kernel. Similarly, transgenic lines exhibited hard wheat like flour properties; flour whiteness and pasting temperature were significantly reduced in the transgenic lines, while the total protein content, damaged starch content, and compound parameter in the Mixograph tests (PT * TW value) showed a significant increase over the wildtype. The results showed that the transformation of the Pinb variants is a powerful strategy to alter the kernel hardness and flour properties in wheat breeding.

[学术文献] Detection of wheat allergens using 2D Western blot and mass spectrometry 进入全文

Science Direct

Background: Wheat allergy is relatively common and the associated clinical manifestations depend on theinvolved molecular allergens as well as on the way of exposure. Different symptoms have been described:wheat-dependent exercise-induced anaphylaxis (WDEIA), atopic dermatitis (AD) and pollen rhinitis (PR).Traditional diagnostic methods do not allow accurate molecular identification of the allergens that areessential for risk assessment and for the choice of the most adapted treatment.Methods: Standardized total protein extracts obtained from wheat seeds were separated by 2D elec-trophoresis. Twenty-one sera with high wheat-specific immunoglobulin E (sIgE) levels were classifiedinto three patients groups based on their clinical profile. These sera were tested by Western blot on 2Dseparated standardized wheat protein extract and their sIgE sensitization profiles were compared.Results: Specific sensitization profiles were identified for each phenotype group. For WDEIA, protein spotsaround 37 kDa (pH 6-9) and 37–50 kDa (pH 5-6) were identified. For AD, spots were observed around50 kDa (pH 9), 10 kDa (pH 9) and 20 to 75 kDa (pH3). For PR, specific spots were located around 90 kDa(pH 9). The mass spectrometry (UHPLC-MS/MS) analysis of these identified spots pointed out severalpotential interesting allergens: Tri a 26, Tri a bA, Tri a 34, Tri a tritin.Conclusions: The present study allowed the identification of different protein areas specific to these stud-ied groups. The protein spots of interest were identified by UHPLC-MS/MS. It has been possible to establisha link between a specific symptomatology and the newly identified responsible allergens.

[前沿资讯] Effect of industrial wastewater on wheat germination, growth, yield, nutrients and bioaccumulation of lead 进入全文

Nature

Due to fresh water scarcity, farmers are using polluted water for irrigation. This research was conducted to study the bioaccumulation of Pb in wheat (Cv. Shafaq-2006). The experiment was comprised of seven treatments of lead i.e. 0–1,000 mg Pb/kg. The results revealed that lead severely reduces germination (− 30%), seedling fresh weight (− 74%), seedling dry weight (− 77%), vigor index (− 89%), tolerance index (− 84%), plant height (− 33%), number of leaves (− 41%), root fresh weight (− 50%), shoot fresh weight (− 62%), root dry weight (− 63%), shoot dry weight (− 71%), and root length (− 45%). The physiological parameters also respond negatively like stomatal conductance (− 82%), transpiration rate (− 72%) and photosynthetic rate (− 74%). Similarly, biochemical parameters also showed negative impacts, like carotenoids (− 41), total chlorophyll (− 43), chlorophyll a (− 42) and chlorophyll b (− 53). Yield parameters like the number of seed/plant, seed weight/plant, 1,000 seed weight and harvest index were reduced by 90%, 88%, 44% and 61%, respectively in T6. In addition, protein contents (− 81%), phosphorous (− 60%) and potassium (− 55%) were highly effected in the highest lead concentration (T6). Lead accumulation was extremely higher in seeds (119%) as compared to control plants. Lead bio-accumulation above threshold concentrations in crop parts is a serious human health concern.

[前沿资讯] Soil labile organic carbon fractions and soil enzyme activities after 10 years of continuous fertilization and wheat residue incorporation 进入全文

Nature

Labile organic carbon (LOC) fractions and related enzyme activities in soils are considered to be early and sensitive indicators of soil quality changes. We investigated the influences of fertilization and residue incorporation on LOC fractions, enzyme activities, and the carbon pool management index (CPMI) in a 10-year field experiment. The experiment was composed of three treatments: (1) no fertilization (control), (2) chemical fertilizer application alone (F), and (3) chemical fertilizer application combined with incorporation of wheat straw residues (F + R). Generally, the F + R treatment led to the highest concentrations of the LOC fractions. Compared to the control treatment, the F + R treatment markedly enhanced potential activities of cellulase (CL), β-glucosidase (BG), lignin peroxidase (LiP), and manganese peroxidase (MnP), but decreased laccase (LA) potential activity. Partial least squares regression analysis suggested that BG and MnP activities had a positive impact on the light-fraction organic carbon (LFOC), permanganate-oxidizable carbon (POXC), and dissolved organic carbon (DOC) fractions, whereas laccase activity had a negative correlation with those fractions. In addition, the F + R treatment significantly increased the CPMI compared to the F and control treatments. These results indicated that combining fertilization with crop residues stimulates production of LOC and could be a useful approach for maintaining sustainable production capacity in lime concretion black soils along the Huai River region of China.

[前沿资讯] How does the self-sufficiency rate affect international price volatility transmissions in the wheat sector? Evidence from wheat-exporting countries 进入全文

Nature

关于国际粮食价格或波动传播的研究主要集中在粮食进口国,在很大程度上低估了粮食不安全或粮食贫困问题在粮食出口国的重要性。本文利用带有动态条件相关(DCC)规范的Glosten、Jagannathan和Runkle三种广义自回归条件异方差(GJR-GARCH)模型,确定了小麦出口国的全球和区域价格指数之间的因果关系,并探讨了价格波动转手的决定因素。研究结果表明,世界价格与本地价格之间的因果关系是双向的,自给自足在减少国际价格波动溢出方面起着重要作用。此外,玉米或大米等替代品的消费起到减震作用,减轻了国际市场的波动性传递。由于COVID-19危机,许多国家的粮食价格更加不稳定,同时还有俄罗斯和哈萨克斯坦对粮食商品出口的限制、国际运输和供应链中断等各种因素。根据我们的分析结果,高度自给自足或自给自足的政策可以帮助出口国家的本地零售市场抵御这些意外事件带来的冲击。

热门相关

意 见 箱

匿名:登录

个人用户登录

找回密码

第三方账号登录

忘记密码

个人用户注册

必须为有效邮箱
6~16位数字与字母组合
6~16位数字与字母组合
请输入正确的手机号码

信息补充