Rapid measurement of phytate in raw soymilk by mid-infrared spectroscopy

The phytate content in soymilk is known to affect tofu curdling. A rapid measurement of phytate from a water extract of soybean (raw soymilk) in an early stage of tofu processing was investigated using mid-infrared spectroscopy (IR) with an ATR accessory. IR absorption of phytate was observed from 1200 cm-1 to 900 cm-1, and saccharide and protein in the extract also had IR absorption in the same region. In order to separate phytate from other components, the phytate was precipitated completely by the addition of calcium under alkaline condition (pH 11.5). The precipitate was dissolved in citrate buffer (pH 6.0) and then used for IR measurement. The absorbance at 1070 cm-1 correlated well with the phytate content of the soymilk. The measurement of phytate in raw soymilk can be done rapidly by FT-IR measurement with an ATR accessory and gives reproducible values, which can be used for the measurement of phytate content in various soybeans for tofu making.     

喀斯特地区不同土地利用方式对土壤有机碳、全氮以及微生物生物量碳和氮的影响

以广西环江大才为代表,选择亚热带典型喀斯特峰林谷地样区,通过对样区土壤进行密集采样和测定分析,研究了土地利用方式对土壤有机碳（O_C）和全氮（TN）含量及土壤微生物生物量碳（B_C）和氮（B_N）含量的影响.结果表明,3种土地利用方式下,土壤有机碳含量在稻田和林地中基本相同,而旱地显著低于稻田和林地.土壤全氮含量为稻田显著高于林地,而林地显著高于旱地.土壤微生物生物量碳含量为稻田显著高于林地,林地显著高于旱地.土壤微生物生物量氮含量在稻田和林地中基本相同,而旱地显著低于稻田和林地.旱地土壤pH值显著低于稻田和林地土壤.3种土地利用方式下,土壤微生物生物量碳与土壤有机碳、土壤微生物生物量氮与全氮含量之间均呈显著的正相关关系.土壤微生物生物量碳和氮含量可以作为评价喀斯特地区土壤质量和肥力的指标之一,对土地利用方式响应较为敏感.     

Production of a white wine and a protein-rich soy flour by yeast fermentation of soybean slurry,soybean milk and the whey from tofu production

A dry white wine with an alcoholic content of 10 to 14% v/v was produced by yeast fermentation of slurried ground soybeans, soybean milk and whey from tofu production. Wines from whey and soybean milk were judged by a 20 member taste panel to be acceptable and comparable to a commercial chablis control. Chemical analysis indicated that the high fat and protein contents of soybeans do not cause a problem in the production of wines from soybeans as the lipids and proteins are precipitated by the acid and alcohol formed during the fermentation. The less recovered following fermentation were dehydrated and ground to a flour having an enriched protein content due to the yeasts and an improved flavor resulting from the yeast fermentation.     

江苏省主要农田杂草种子库物种组成和多样性及其与环境因子的相关性分析

采用水洗镜检法对江苏省31个农田样点(包括旱田和水田)0～15 cm土层土壤杂草种子库的种类组成和物种多样性进行了调查研究;采用典范对应法分析了杂草种子库种类与环境因子(包括淹水天数、土壤有机质含量、土壤pH、年降水量、年均温、样点经度和样点纬度)的相关性并绘制了样点和种类与环境因子的二维排序散点图.调查结果表明:在31个样点的土壤杂草种子库中共检测到杂草种子15科54种,旱田和水田各有41和45种,二者共有种类占多数但优势种有差异,通泉草[ Mazus japonicus (Thunb.) Kuntze]、异型莎草(Cyperus difformis L.)、水苋菜(Ammannia baccifera L.)、千金子[Leptochloa chinensis (L.) Nees]、棒头革(Polypogon fugax Nees ex Steud.)和牛繁缕[ Malachium aquaticum (L.) Fries]等种类为二者的共有优势种;杂草种类最多的为禾本科(Gramineae)和莎草科(Cyperaceae),分别占种类总数的22.6％和20.8％.旱田不同样点杂草种子库的优势种类变化较大,而水田杂草种子库优势种较稳定;二者优势种频度差异较大,旱田中频度高于0.30的杂草有19种,水田中频度高于0.50的杂草有20种;旱田和水田中平均重要值大于0.03的杂草各有11和9种,这些频度高的种类重要值也较大.旱田和水田土壤种子库种子密度分别为21 015和37 847 m-2,平均为31 008 m-2;旱田3层土壤中种子密度差异不显著,而水田上、中层土壤的种子密度显著高于下层.旱田以夏熟和秋熟杂草为主,而水田则以水田和夏熟杂草为主.按形态类型划分,水田及旱田中杂草种类数和密度从大到小均依次排序为阔叶草类、禾草类、莎草类,且水田中这3类杂草的种类数和种子密度均高于旱田.与旱田相比,水田杂草种子库的物种丰富度指数(S)、Shannon-Wiener 指数(H')和Simpson指数(D)较高,但Pielou均匀度指数(E)较低;旱田杂草种子库的S、H'和D指数随土层深度增加而降低、E指数逐渐升高,水田各土层的物种多样性指数则无明显变化趋势.第1种类排序轴与淹水天数负相关性最高(R=-0.8143),第2种类排序轴与年降水量和经度也有较高的负相关性;相关性分析和CCA分析结果均表明淹水天数是影响杂草种子库群落构成的最大因素.通过二维排序可将31个样点分为旱田和水田2大类,旱田可划分为长期旱连作和水旱轮作2个亚类;水田可划分为淮河以北地区和淮河以南长江流域地区2个亚类.研究结果说明:杂草种子库潜群落优势种与地上部农田杂草显群落优势种具有一致性,通过土壤杂草种子库的研究可以预测地上杂草的发生和危害情况.     

花生粕脂肪含量对豆腐品质的影响

为了确定适用于制备花生豆腐的原料的脂肪含量,以低温花生粕为原料,采用谷氨酰胺转氨酶（transglutaminase,TG）和高温微压煮浆（high-temperature pressure cooking,HTPC）工艺制备花生豆腐,研究不同花生粕脂肪含量（6.89%、10.12%、15.43%、20.28%和25.54%）对豆腐质构的影响,对比花生豆腐与市售大豆豆腐的耐煮性和色泽,并分析加工过程中花生蛋白的结构变化。结果表明,花生粕脂肪含量对豆腐质构有显著影响（P<0.05）,除脂肪含量为25.54%的花生粕外,其他脂肪含量的花生粕均可用于制备花生豆腐。当花生粕脂肪含量为6.89％时,可制得与市售大豆石膏豆腐的质构、耐煮性相当的花生豆腐产品,且其黄度值b（8.38）显著小于大豆石膏（15.86）和卤水（16.56）豆腐（P<0.05）,具有色泽优势。而对于花生蛋白结构变化的分析表明,当花生粕脂肪含量相对较低（6.89%~20.28%）时,TG对花生蛋白的作用效果较好,进一步施加HTPC处理可使花生蛋白完全变性,并且通过形成疏水相互作用和二硫键以维持豆腐凝胶结构。研究结果为花生豆腐的加工提供了技术指导和理论支撑。     

Natural alleles of a uridine 5ʹ-diphospho-glucosyltransferase gene responsible for differential endosperm development between upland rice and paddy rice

Traditional upland rice generally exhibits insufficient grains resulting from abnormal endosperm development compared to paddy rice. However, the underlying molecular mechanism of this trait is poorly understood. Here, we cloned the uridine 5ʹ-diphospho (UDP)-glucosyltransferase gene EDR1 (Endosperm Development in Rice) responsible for differential endosperm development between upland rice and paddy rice by performing quantitative trait loci analysis and map-based cloning. EDR1 was highly expressed in developing seeds during grain filling. Natural variations in EDR1 significantly reduced the UDP-glucosyltransferase activity of EDR1^YZN compared to EDR1^YD1, resulting in abnormal endosperm development in the near-isogenic line, accompanied by insufficient grains and changes in grain quality. By analyzing the distribution of the two alleles EDR1^YD1 and EDR1^YZN among diverse paddy rice and upland rice varieties, we discovered that EDR1 was conserved in upland rice, but segregated in paddy rice. Further analyses of grain chalkiness in the alleles of EDR1^YD1 and EDR1^YZN varieties indicated that rice varieties harboring EDR1^YZN and EDR1^YD1 preferentially showed high chalkiness, and low chalkiness, respectively. Taken together, these results suggest that the UDP-glucosyltransferase gene EDR1 is an important determinant controlling differential endosperm development between upland rice and paddy rice.     

中国大豆(Glycine max)品种及种质资源主要品质状况分析

对2003年中国19个主要大豆种植省(直辖市、自治区)的大豆品种与种质资源的蛋白、脂肪含量和部分大豆品种水溶性蛋白含量进行了分析.结果表明,大豆种质资源的蛋白含量和蛋脂总量总体上与品种持平.品种脂肪含量总体上明显高于种质资源脂肪含量,说明当前中国种植的大豆中高脂肪的品种已经占有一定的比例. 北方、黄淮海、南方三大生态区大豆品种和种质资源蛋白含量呈现自北向南递增的趋势,而脂肪含量呈现递减趋势.生态、气象因子对大豆蛋白含量的影响大于对脂肪含量的影响.大豆水溶性蛋白含量总体上较高,基本适合豆制食品加工业的需要.     

大豆豆乳和豆腐产量、品质及有关加工性状的遗传变异

采用全国各地的261个大豆品种为材料,研究豆乳和豆腐产量、品质及有关加工性状的遗传变异.结果表明豆乳和豆腐加工过程中每100g干籽粒平均生产干豆乳71.92g,生产干豆腐51.80g,损失豆渣干物质25.76g,损失乳清干物质20.12g.干豆乳蛋白质、脂肪和总糖的含量分别为51.85%、22.55%和18.42%,干豆腐蛋白质、脂肪和总糖的含量分别为46.22%、24.58%和19.36%.豆乳和豆腐产量、品质及有关加工性状在品种间的差异均达到极显著水平,变异系数都较大,从中筛选出一批优异种质.     

酸性硫酸盐土水改旱后土壤化学性状的变异初报

探讨了酸性硫酸盐水稻土改为旱作后土壤化学性状的变异以及比较不同利用方式之间的经济效益．结果表明,酸性硫酸盐水稻土改种甜玉米和蔬菜后,土壤化学性状发生显著变化．耕层土壤酸度、水溶性硫酸根含量、土壤活性铝和活性铁含量均显著降低．经济效益得到显著提高．建议对水改旱后的环境效应进行深入研究以及进行定位观测,以便合理利用这一特殊的土壤资源     

Effect of phytate on aflatoxin formation by Aspergillus parasiticus grown on different grains

Aflatoxin production by Aspergillus parasiticus on corn, soybean, and cottonseed in the absence or presence of added sodium phytate was examined. No variation in aflatoxin concentrations was found in raw, chemically sterilized, or autoclaved soybeans whereas a five-fold reduction in total aflatoxins was found in cottonseed after addition of 330 g sodium phytate to 10 g of autoclaved material. However, phytate did not affect aflatoxin production on non-sterile cottonseeds, although in corn a slight inhibition was found. Extraction of raw soybeans with hexane allowed production of 20-fold more aflatoxins, but levels were still lower than those found on rice or corn. Part of this relative inhibition in soybeans may arise from a heat-unstable, polar solvent-soluble, dialyzable factor present in soybeans. Our results support the conclusion that phytate is not the factor in soy responsible for its relative resistance to aflatoxin formation.     

干旱胁迫对水稻水分利用效率的影响

通过特殊自然干旱胁迫的方法,研究不同干旱胁迫对水稻的水分利用效率（ＷＵＥ）的影响,在一定供水量时,水稻的ＷＵＥ随供水量的增加而下降,但水稻旱种时,却因供水量过低,干旱胁迫严重,ＷＵＥ值为最低。不同品种的水稻ＷＵＥ存在较大的差异,抗旱性强的品种具有较高ＷＵＥ,因此选用具有较高ＷＵＥ的品种,是水稻节水栽培的关键。     

海南山栏稻稻米品质分析及优异资源筛选

海南山栏稻是一类地方特有旱稻,是海南中部山区少数民族赖以生存的粮食作物,已深深植根于黎苗文化之中。本研究检测了17个海南山栏稻品种的稻米品质,并对品质性状进行了差异性和相关性分析,对供测品种进行了聚类分析。结果表明,大部分山栏稻米的糊化温度较低,属于中、软胶稠度和低直链淀粉含量稻米,蒸煮和食味品质较好。17个海南山栏稻品种被初步分成2类,其中2个品种被鉴定为优质糯米,而且发现了独特的黑尾山栏稻,其稻米加工品质、外观品质和食味品质较好。本研究为海南山栏稻品种改良和育种利用提供了参考。     

海岛棉与陆地棉叶绿素含量变化的差异研究

以5份陆地棉和4份海岛棉为材料,研究了整个发育进程中陆地棉和海岛棉叶绿素的变化规律之间的差异,结果显示：陆地棉与海岛棉的叶绿素a、叶绿素b和叶绿素a＋b各有不同动态变化规律,其叶绿素a/b在整个发育进程中的变化也有差异。海岛棉与陆地棉的叶绿素a变化趋势有较大差别,陆地棉的叶绿素a含量在6月18日（苗期）最高,峰值出现在8月6日,海岛棉峰值、最大值均在7月4日（现蕾期）;叶绿素b含量表现为陆地棉、海岛棉峰值均在8月6日（花铃期）,但海岛棉平均值高于陆地棉;陆地棉的叶绿素a＋b和叶绿素a曲线相似,海岛棉的叶绿素a＋b和叶绿素b曲线相似;陆地棉叶绿素a/b值表现苗期最大,然后迅速下降,海岛棉a/b值表现普遍低于陆地棉,其变化趋势为前期在7月4日出现峰值,然后下降再升高。实验说明陆地棉和海岛棉叶绿素的合成机制、调控机理可能不同。     

Characterization of the Major Capsid Genes (g23) of T4-Type Bacteriophages in the Wetlands of Northeast China

To obtain genetic information and to evaluate the composition of T4-type bacteriophage (phage) communities in wetlands, environmental soil and water DNAs were obtained from two natural wetlands dominated by Carex lasiocarpa and Deyeuxia angustifolia plant species, and a neighboring paddy field in Sanjiang plain of northeast China. The biomarker gene of g23, which encodes the major capsid protein of T4-type phages, was amplified with primers MZIA1bis and MZIA6, and the PCR products were cloned and sequenced. In total, 96 and 50 different g23 clones were obtained from natural wetlands and a paddy field, respectively. A larger number of clones with low levels of identity to known sequences were found in water than in soil both in the natural wetlands and the paddy field, suggesting that many of T4-type phages in wetland water and paddy floodwater in Sanjiang plain are uncharacterized. Phylogenetic analyses showed that the g23 clones in natural wetlands, irrespective of water and soil, were distinctly different from those in marine waters, lake waters, and upland black soils, but were similar to those in paddy fields. The UniFrac analysis of g23 assemblages indicated that T4-type phage community compositions were different between soils and waters, and also were different between the natural wetlands and the paddy field. In general, the global analysis of g23 clone assemblages demonstrated that T4-type phage community compositions were different among natural wetlands, marines, lakes, paddy fields, and upland black soils.     

Assessment of selenium bioavailability from naturally produced high-selenium soy foods in selenium-deficient rats

We assessed the bioavailability of selenium (Se) from a protein isolate and tofu (bean curd) prepared from naturally produced high-Se soybeans. The Se concentrations of the soybeans, the protein isolate and tofu were 5.2 ± 0.2, 11.4 ± 0.1 and 7.4 ± 0.1 mg/kg, respectively. Male weanling Sprague–Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1 μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet containing 14, 24 or 30 μg Se/kg from the protein isolate or 13, 23 or 31 μg Se/kg from tofu, respectively. l-Selenomethionine (SeMet) was used as a reference. Selenium bioavailability was determined on the basis of the restoration of Se-dependent enzyme activities and tissue Se concentrations in Se-depleted rats, comparing those responses for the protein isolate and tofu to those for SeMet by using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Furthermore, supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in the Se concentrations of plasma, liver, muscle and kidneys. These results indicated an overall bioavailability of approximately 101% for Se from the protein isolate and 94% from tofu, relative to SeMet. We conclude that Se from naturally produced high-Se soybeans is highly bioavailable in this model and that high-Se soybeans may be a good dietary source of Se.     

红壤丘陵景观单元土壤有机碳和微生物生物量碳含量特征

为了探讨我国亚热带红壤丘陵区不同利用方式下土壤有机碳(SOC)和土壤微生物生物量碳(SMB-C)含量的特征,在湖南省桃源县选取典型样区,通过密集取样,分析了红壤丘陵景观单元内水田、旱地、林地、果园4种典型利用方式下表层土壤(0～20 cm)SOC和SMB-C含量.结果表明,典型红壤丘陵景观单元中SOC含量高低的顺序为水田(16.0 g·kg^-1)＞旱地(11.2 g·kg^-1) ＞果园(9.5 g·kg^-1)＞林地(8.4 g·kg^-1),SMB-C含量则为水田(830 mg·kg^-1)＞旱地(361 mg·kg^-1)＞林地(200 mg·kg^-1)＞果园(186 mg·kg^-1),且在不同利用方式下SOC与SMB-C均呈极显著正相关(P＜0.01),说明本研究区内各土地利用类型的土壤SMB-C含量变化可以敏感地指示SOC的动态.研究结果还表明,将我国亚热带红壤丘陵林地开垦为果园或耕地后,表层土壤 SOC含量不可能降低.     

鄱阳湖区土地利用的生态效应

在构建鄱阳湖区土地利用地理数据库的基础上,利用区域生态质量指数与土地利用变化生态贡献率对鄱阳湖区土地利用生态效应进行了定量研究.结果表明,鄱阳湖区1990年区域生态质量指数平均值为7.60,2002年为7.62,总体生态质量介于灌木林地、疏林地等土地利用类型之间.1990-2002年鄱阳湖区区域生态质量指数上升的主要动力为水库坑塘、有林地和疏林地的扩大;生态质量指数下降的主要动力依次为水田、中覆盖度草地的减少.在土地利用转移贡献率上,水田转为有林地、旱地转为有林地、水田转为疏林地、水田转为水库坑塘的生态贡献率之和达52.96%,为主导土地利用的正向转移类型.有林地转为水田、有林地转为旱地、水田转为农村居民点的生态贡献率之和达39.89%,为主导土地利用的反向转移类型.     

Comparison of crop productivity and soil microbial activity among different fertilization patterns in red upland and paddy soils

Soil enzyme activity and microorganism community can be changed through different long-term fertilization patterns. However, the effect of different fertilization practices on soil microorganisms might differ among crop systems. The objective of the study was to reveal the change of soil enzyme activity and soil microorganism community in different fertilizations both in upland and paddy soils. Therefore, based on long-term fertilization experiments in upland soil started in 1986 and adjacent paddy soil experiment commenced in 1981, with both consisting of 4 treatments: Control (no fertilization), N (only nitrogen fertilizer), NPK (nitrogen, phosphate and potassium fertilizers) and NPKM (nitrogen, phosphate and potassium fertilizers plus organic manure), grain yield, soil fertility, activities of soil urease, catalase, acid phosphatase, microorganism community (the number of bacteria, fungus and actinomycete) were analyzed. The result showed that: the highest grain yield was attained under the application of chemical fertilizers plus manure, as compared with Control, NPKM significantly increased the grain yield by 908.63% in corn and 118.80% in rice (p < 0.05). Meanwhile, NPKM treatment increased significantly soil organic matter and nutrient contents in upland and paddy soils. Interestingly, there was no significant difference in soil pH among all the treatments of paddy soil, but in upland, NPKM increased pH in comparison to Control by 23.06% (1.15 units of pH). Compared with Control, soil urease, catalase activities, bacteria and actinomycete numbers of NPKM were increased by 321.39%, 129.64%, 229.79%, 85.81% in upland soil, and 25.11%, 251.12%, 292.83%, 196.34% in paddy soil. However, in paddy soil, the soil acid phosphatase activity of Control, NPK and NPKM treatments were higher than upland soil by 34.87%, 44.81%, 52.73% and 30.11%. Then, the soil fungus and actinomycete numbers of paddy soil were lower than upland soil by 20.20% and 88.29%. Therefore, it indicated that long-term application of chemical and organic fertilizers delivered highest productivity in both experiment but the effect of fertilizer practices differed between land uses.     

基因型与环境对小麦籽粒蛋白质和淀粉品质的影响

选用山东省近年来已推广和区试的10个冬小麦品种为材料,于2001～2003年在9个不同环境条件的试验点进行两年多点试验,分析了山东省不同地区小麦品质性状特点,依据品质指标将山东省分为个类型区,并研究了基因型和环境及其互作对小麦主要品质性状的影响.结果表明,品种与环境对小麦主要品质性状指标均有显著影响;蛋白质和面筋百分含量变异的主要原因是环境的差异;粉质仪参数的变异主要是品种和环境的共同作用;而淀粉含量、峰值黏度和稀懈值变异的各影响因素互作效应大于独立效应,在独立效应中,品种影响大于环境影响.     

灌溉方式对黄淮稻区优质粳米品质的影响

为探明不同水深处理对优质稻米的影响,研究了湿润、浅水、深水3种灌溉方式对优质粳稻(圣稻14、圣稻2572、圣稻18)籽粒外观、稻米直链淀粉、蛋白质含量及淀粉RVA谱的影响,分析了稻米品质与理化指标之间的关系.结果表明: 浅水灌溉下籽粒面积、周长、粒长、稻米蛋白质含量显著高于其他灌溉方式,垩白率和垩白度的表现相反;RVA谱的最高黏度和热浆黏度值以湿润灌溉最高,深水灌溉最低,最终黏度值以深水灌溉最低;不同品种RVA谱的崩解值、消减值、回复值及稻米直链淀粉含量对3种灌溉方式的响应存在明显的基因型差异.圣稻14以湿润灌溉的食味品质最好,圣稻18则以深水灌溉最好.相关分析表明,稻米RVA谱特征值与稻米外观指标及蛋白质含量之间存在显著的相关性.回归与通径分析表明,粒型是影响崩解值与消减值的主要因子,而稻米蛋白质与直链淀粉含量是影响回复值的主要因子.