REVIEW: Cereal Carbohydrates and Colon Health

Providing balanced energy and nutrients for microbiota growth is essential for the maintenance of the colon ecosystem, and dietary fiber (DF) fermentation, particularly butyrogenic fermentation, augments colon health. Cereal DF, which are the complex carbohydrates of cereal grains that escape small intestine digestion and function either as substrate for colonic fermentation or as bulking material, are a dietary measure to mitigate the occurrence of certain colonic diseases, and perhaps to some degree act as therapeutic agents. In developed Western countries, as well as in many developing countries, colon cancer is one of the major causes for premature death and disability, and inflammatory bowel disease and other colonic disorders have become serious health issues. The function of DF in colon health is mediated through its physicochemical properties (e.g., water‐holding for laxative effect) or effect on colon microbiota (e.g., leading to immune regulation), as well as through colonic fermentation products, principally the short chain fatty acids (SCFA) of acetate, propionate, and butyrate. Due to the chemical diversity and complexity of DF and because not all DF materials function equally, new developments in DF fermentation behavior (pattern and end product profile) will be reviewed from a structure‐function viewpoint. The effect of cereal DF, mainly nonstarch cereal polysaccharides and resistant starch on colonic microbiota, fermentation products of SCFA, microbiota modulation, as well as on colon health will be summarized.     

REVIEW: Developments in Our Understanding of Sorghum Polysaccharides and Their Health Benefits

The composition and structure of sorghum polysaccharides are remarkably similar to those in maize. Sorghum grain is rich in starch, cellulosic and noncellulosic polysaccharides (mainly glucuronoarabinoxylans [GAX]). Sorghum starch is similar to maize starch in terms of amylopectin, but the amylose may be more branched. This may account for sorghum starch having a generally slightly higher gelatinization temperature. The GAX in sorghum are highly substituted with glucuronic acid and arabinose, but the degree of these substitutions is lower when compared with maize GAX. Sorghum polysaccharides themselves are not sufficiently functional to allow the production of high‐quality baked goods. Sorghum has generally lower starch digestibility than maize. This is primarily due to the endosperm protein matrix, cell wall material, and tannins (if present) inhibiting enzymatic hydrolysis of the starch. Protein disulfide bond cross‐linking involving the kafirin prolamins in the protein matrix around the starch granules seems to be of major importance in reducing starch digestibility. It does not seem that sorghum polysaccharides, per se, have any unique health‐promoting effects. Any health‐promoting effects related to sorghum polysaccharides seem to be due to interactions between the polysaccharides and the endosperm matrix protein and phenolics.     

REVIEW: Molecular Diversity in Pulse Seed Starch and Complex Carbohydrates and Its Role in Human Nutrition and Health

Seven major pulse crops account for ≈90% of global pulse production. Pulses are an important component of human nutrition as sources of proteins, carbohydrates, and minor nutrients such as vitamins and minerals. The major pulse seed storage polysaccharide is starch, which is made up of highly branched amylopectin and sparsely branched amylose. Pulse starches generally contain a higher concentration of amylose as compared to cereal and tuber starches. The nonstarch complex carbohydrates are major components of dietary fiber including cellulose, hemicellulose, and pectic polysaccharides with considerable structural diversity. Diets rich in pulses are associated with health benefits such as reduced calorific content, reduced or no effect on blood glucose levels (low glycemic index), and improved heart health. These health benefits have been attributed to the high amylose concentration (>30%) that gives rise to resistant starch that, along with dietary fiber, remains undigested in the small intestine but is fermented by the microbiota in the colon. Colonic fermentation increases the growth of beneficial bacteria and production of short chain fatty acids which have been associated with reduced risk of colon cancer. Clinical trials with human subjects to confirm the beneficial effects of diets rich in pulses are inconclusive. Advances in genetic strategies to develop pulse seeds with desired carbohydrate concentration and composition, carbohydrate structure characterization, combined with utilization of in vitro and in animal models may be helpful to identify carbohydrate structure function relationship responsible for beneficial effects on human health associated with pulse consumption.     

Review of Spirulina in Human Nutrition and Health

No abstract available for this article.     

谷物介电性质及其在含水量测量中的应用

对谷物介电性质的概念,测量方法、影响因子和预测模型进行了综述、介绍了利用介电性质测量谷物含水量的方法以及近期研究动向。     

猕猴桃果实贮藏期间细胞壁多糖物质降解特性及组织结构差异分析

为了深入了解猕猴桃果实采后细胞壁多糖物质降解及组织结构变化与果实贮藏性的关系,本研究以红阳和华特猕猴桃果实为试材,对25和4℃贮藏期间的细胞壁多糖物质含量及果胶降解酶活性进行测定,并比较两品种果实在25℃贮藏期间的细胞显微结构和钙组分含量差异。结果表明,在25和4℃贮藏条件下,随着贮藏时间的延长,红阳和华特猕猴桃果实中半纤维素（HCL）、纤维素（CL）和共价结合型果胶（CSP）含量不断降低,水溶性果胶（WSP）含量不断上升,离子结合型果胶（ISP）含量相对稳定。红阳猕猴桃各细胞壁多糖组分含量变化速度较快。两品种猕猴桃果实硬度均与WSP含量呈显著负相关,与CSP含量呈显著正相关。果胶降解酶活性检测结果显示,25℃贮藏前期,红阳猕猴桃中果胶酸裂解酶（PL）和β-半乳糖苷酶（β-Gal）活性显著高于华特;贮藏中后期,红阳中果胶甲酯酶（PME）活性显著高于华特。4℃贮藏期间,红阳中PME活性仍显著高于华特;4℃贮藏前期,红阳中β-Gal活性与华特无显著差异,而PL活性低于华特。相关性分析表明,25℃贮藏期间,与红阳和华特果实软化显著相关的果胶降解酶分别是PME和PL;4℃贮藏期间,与华特果实软...     

Quantification and In Vitro Bioaccessibility of Selenium from Osborne Fractions of Selenium‐Rich Cereal Grains

Cereal crops cultivated in the seleniferous belt of Punjab, India, were observed to hyperaccumulate a significantly high concentration of selenium (20–123 µg/g). Selenium concentration (µg/g) in storage proteins of wheat, maize, and rice, namely, albumin (401, 280, and 29, respectively), globulin (264, 192, and 242, respectively), glutelin (563, 359, and 178, respectively), and prolamin (629, 339, and 257, respectively) indicated variable selenium levels, with prolamin contributing significantly higher levels of selenium when compared with other proteins with reference to the total concentration of the protein fraction. The simulated gastric and gastrointestinal digestion studies indicated better accessibility of selenium during intestinal digestion, with variability across proteins and cereal types. The observations provide an insight into the bioavailability of selenium in selenium‐rich cereal grains, used in the study, and their potential use as source for selenium supplementation to deficient populations, or as “bioactive” selenium‐rich nutraceutical blends for health benefits.     

Distribution of Accumulated Aluminum and Changes in Cell Wall Polysaccharides in Eucalyptus camaldulensis and Melaleuca cajuputi under Aluminum Stress

Distribution of aluminum (Al) within plant components and Al-induced changes in cell wall polysaccharides in root tips of Eucalyptus camaldulensis Dehnh. seedlings were compared with those of Melaleuca cajuputi Powell. In E. camaldulensis , 0.5 mM Al (pH 4.2 for 40 d) reduced plant dry weight by 50%, increased callose concentration in the root tips and induced leaf necrosis. In comparison with M. cajuputi , Al concentrations were higher in roots and leaves of E. camaldulensis on both a fresh weight basis and in the cell sap, but were lower in the cell wall. Al increased pectin, hemicellulose and cellulose concentration in the cell walls of E. camaldulensis root tips. Al-induced leaf necrosis and growth reduction in E. camaldulensis is discussed in the context of potentially toxic concentrations of Al in plant tissue and changes in polysaccharide content which could reduce water and nutrient uptake and cell wall extensibility in roots.     

Distribution of Accumulated Aluminum and Changes in Cell Wall Polysaccharides in Eucalyptus camaldulensis and Melaleuca cajuputi under Aluminum Stress

Distribution of aluminum (Al) within plant components and Al-induced changes in cell wall polysaccharides in root tips of Eucalyptus camaldulensis Dehnh. seedlings were compared with those of Melaleuca cajuputi Powell. In E. camaldulensis, 0.5 mM Al (pH 4.2 for 40 d) reduced plant dry weight by 50%, increased callose concentration in the root tips and induced leaf necrosis. In comparison with M. cajuputi, Al concentrations were higher in roots and leaves of E. camaldulensis on both a fresh weight basis and in the cell sap, but were lower in the cell wall. Al increased pectin, hemicellulose and cellulose concentration in the cell walls of E. camaldulensis root tips. Al-induced leaf necrosis and growth reduction in E. camaldulensis is discussed in the context of potentially toxic concentrations of Al in plant tissue and changes in polysaccharide content which could reduce water and nutrient uptake and cell wall extensibility in roots.     

桂林市菜地土壤和蔬菜铜含量及其健康风险

在桂林地区蔬菜和菜地土壤铜含量进行大规模调查基础上,评价其污染程度,并用THQ评估经食用蔬菜摄入铜的健康风险。结果显示,桂林地区菜地土壤铜含量范围、中值、算术均值和几何均值分别为11.69～348.8mg·kg-1和27.41、34.62、29.43mg·kg-1,与桂林市土壤背景值相比,桂林市菜地土壤铜没有明显的积累;桂林地区蔬菜铜含量范围和平均值分别为0.032～3.530mg·kg-1和0.324mg·kg-1,与其他城市蔬菜铜含量相比,桂林地区蔬菜铜含量处于较低水平,通过蔬菜摄入铜的健康风险小。蔬菜对铜的富集能力以辣椒最高,因而其抗污染能力较差,白菜、包菜和萝卜对铜的富集能力最低。     

Analysis of Alkylresorcinols in Cereal Grains and Products Using Ultrahigh-Pressure Liquid Chromatography with Fluorescence, Ultraviolet, and CoulArray Electrochemical Detection

Alkylresorcinols are phenolic lipids, with homologues ranging from C17 to C25, found in high concentrations in whole grain wheat and rye, lower concentrations in barley, and negligible concentrations in refined wheat flour. The analysis of alkylresorcinols is of importance due to their potential as biomarkers of whole grain intake and emerging evidence for some biological effects. Present HPLC methods have insufficient resolution for accurately quantitating the mix of alkyl- and alkenylresorcinols found in rye. An ultrahigh-pressure liquid chromatography method was developed, and three detection methods (CoulArray (CAED), ultraviolet (UV), and fluorescence detection (FD)) were compared for cereal alkylresorcinol analysis. The lower limits of quantitation and detection were 50 and 20 pg injected, 5 pg and 2 pg injected, and 500 and 1250 pg injected for FD, CAED, and UV, respectively. FD and CAED provided similar results, with some bias for higher results with FD (<10% difference). UV detection generally resulted in overestimation of alkylresorcinol concentrations. The method was applied to cereal (15) and cereal product (90) samples mainly from the United States with results in the same range as previous methods. The improved resolution with this method allows facile analysis of alkylresorcinols from cereal products, including minor unsaturated homologues such as those found in rye.     

广州市蔬菜和菜地土壤砷含量及其健康风险研究

测定了广州市郊区菜地土壤(n=120)、菜地蔬菜(n=109)和市售蔬菜(n=237)中砷含量,结合广州居民蔬菜消费情况,分析了砷对广州居民的健康风险影响.结果表明:不同类型菜地土壤砷含量不同,为菜园土(12.94±9.78)mg/kg>水稻土(8.67±10.24)mg/kg>赤红壤(4.17±3.70)mg/kg,土壤质量主要属于二级标准以内;菜地蔬菜砷含量范围为ND～0.179 mg/kg,均值为(0.017±0.024)mg/kg;市售蔬菜砷含量范围为ND-0.314 mg/kg,含量变化为豆类(0.038±0.047)mg/kg)>根茎类(0.027±0.031)mg/kg>茄类(0.025±0.030)mg/kg>叶菜类(0.024±0.022)mg/kg>葱蒜类(0.019±0.025)mg/kg>瓜类(0.017±0.020)mg/kg,所有蔬菜均没有超过我国食品中砷的限量卫生标准(GB-4810-94).广州市居民从蔬菜中摄入的砷为0.045 mg/d,叶菜类和根茎类蔬菜是主要的贡献者.     

毛果苔草湿地开垦后土壤中主要营养元素垂直分异

以三江平原毛果苔草湿地及其开垦后的农田为研究对象 ,探讨了湿地开垦前后土壤中主要营养元素含量差异及垂直分异。结果表明 ,毛果苔草湿地土壤中主要营养元素含量要远高于农田土壤中营养元素含量 (土壤表层 K元素除外 ) ,其中 ,全 N含量相差 2 0多倍 ;毛果苔草湿地土壤中主要营养元素的垂直分异显著 ,都在 4 0 %以上 ,其中全 N含量的变异系数最高 ,达到 81.32 % ,而农田土壤中主要营养元素的垂直分异不太显著 ,都在 2 4 %以下 ,主要受水分条件和有机质的含量控制     

Sensitivity of Scottish Upland Moorland Podzols Derived from Sandstones and Quartzites to Acidification: the Potential Importance of the Mobile Anion Effect

Soil samples were collected from the main horizons of Scottish upland moorland podzols derived from quartzite or Devonian and Torridonian sandstones. The soils were subjected to routine chemical analysis and the results studied in relation to potential acidification effects of atmospheric deposition. Stronger correlations were observed for soil pH_water than for soil pH in CaCl₂ with wet deposition fluxes of mobile strong-acid anions. Exchangeable Al³⁺ correlated more strongly with wet deposition fluxes of mobile strong-acid anions than with H⁺ deposition flux. It is suggested that the direct effects of mobile anion enhancement upon soil pH_water must be taken into account when assessing damage to, and hence critical loads of, acidification-sensitive mineral soils.     

SE—Structures and Environment: Measurements of Isothermal Compact Ceiling Jets Generated by Rectangular Wall Inlets

Studies of the development of the compact ceiling air jets generated by rectangular wall inlets were carried out. Two types of inlets were applied in the experimental studies. One inlet was designed with an elliptic profile in the contraction section according to the ISO standard for a long-radius nozzle (ISO inlet). Another was a pre-manufactured side-wall inlet with bottom-hinged flap and a top guiding plate (flap inlet). The inlets were placed in the inlet wall and the openings were 0·49 m from the ceiling with an incline angle of 20° pointing upward to the ceiling.Results showed that the three-dimensional jets created by the two types of inlets had similar characteristics in the fully developed turbulent regions. In the vertical symmetric plane, the jet velocity profiles may be represented by a universal similarity model with consideration of the shear stress caused by the ceiling. In the horizontal plane parallel to the ceiling, jet velocity profiles may be described by a Gaussian distribution model. The estimated horizontal distances from the inlet opening to the virtual origin of zero were applied according to the analysis of centre velocity decays of the jets. The velocity decay constants were 5·8 for the ISO inlet and 3·6 for the flap inlet. The jet generated with the flap inlet had lower maximum centre velocity and wider spread angle than the jet created with the ISO inlet. Non-linear model estimation resulted in the jet expansion coefficients of 0·07 and 0·32 for the ISO inlet and 0·08 and 0·50 for the flap inlet in vertical and horizontal directions, respectively.     

Forest Health in North America: Some perspectives on Actual and Potential Roles of Climate and Air Pollution

The perceived health of forest ecosystems over large temporal and spatial scales can be strongly influenced by the frames of reference chosen to evaluate both forest condition and the functional integrity of sustaining forest processes. North American forests are diverse in range, species composition, past disturbance history, and current management practices. Therefore the implications of changes in environmental stress from atmospheric pollution and/or global climate change on health of these forests will vary widely across the landscape. Forest health surveys that focus on the average forest condition may do a credible job of representing the near-term trends in economic value while failing to detect fundamental changes in the processes by which these values are sustained over the longer term. Indications of increased levels of environmental stress on forest growth and nutrient cycles are currently apparent in several forest types in North America. Measurements of forest ecophysiological responses to air pollutants in integrated case studies with four forest types (southern pine, western pine, high elevation red spruce, and northeastern hardwoods) indicate that ambient levels of ozone and/or acidic deposition can alter basic processes of water, carbon, and nutrient allocation by forest trees. These changes then provide a mechanistic basis for pollutant stress to enhance a wider range of natural stresses that also affect and are affected by these resources. Future climatic changes may ameliorate (+ CO2) or axacerbate (+ temperature, + UV-B) these effects. Current projections of forest responses to global climate change do not consider important physiological changes induced by air pollutants that may amplify climatic stresses. These include reduced rooting mass, depth, and function, increased respiration, and reduced water use efficiency. Monitoring and understanding the relative roles of natural and anthropogenic stress in influencing future forest health will require programs that are structured to evaluate responses at appropriate frequencies across gradients in both forest resources and the stresses that influence them. Such programs must also be accompanied by supplemental process -oriented and pattern -oriented investigations that more thoroughly test cause and effect relationships among stresses and responses of both forests and the biogeochemical cycles that sustain them.     

西南某矿区土壤重金属的人体生物有效性及健康风险评估

利用生物可给性修正后土壤重金属经口摄入的人体健康风险值也可能被高估,而应用体内实际摄入剂量（生物有效性）作为健康风险评价指标将更为准确,但是基于生物有效性的矿区土壤重金属污染健康风险评估报道较少。以云南文山某矿区为研究对象,分析了5个土壤样点中镉（Cd）、铅（Pb）、锌（Zn）和铜（Cu）的含量,通过体外消化法测定了4种重金属的生物可给性,并结合BALB/c白变种实验室小鼠实验分析了重金属Cd的相对生物有效性（RBA）,基于此探讨该矿区土壤重金属Cd、Pb、Zn和Cu对人体产生的健康风险。结果表明,本研究区域土壤Cd污染较为严重,含量为2.06 mg·kg-1。四种重金属的生物可给性在胃相中的范围分别为24.29%～50.55%、7.68%～17.87%、24.61%～32.18%、7.75%～37.87%,在肠相中分别下降至22.78%～44.32%、1.64%～5.22%、14.10%～28.11%、8.51%～31.49%。动物实验测得的Cd在肝脏中RBA为1.31%～48.39%,肾脏中为2.83%～8.58%,肝和肾复合器官中为4.60%～50.95%,且肝和肾复合器官是测定...