Isotopic labelling for the characterisation of HNE-sequestering agents in plant-based extracts and its application for the identification of anthocyanidins in black rice with giant embryo

Reactive carbonyl species (RCS) are cytotoxic molecules that originate from lipid peroxidation and sugar oxidation. Natural derivatives can be an attractive source of potential RCS scavenger. However, the lack of analytical methods to screen and identify bioactive compounds contained in complex matrices has hindered their identification. The sequestering actions of various rice extracts on RCS have been determined using ubiquitin and 4-hydroxy-2-nonenal (HNE) as a protein and RCS model, respectively. Black rice with giant embryo extract was found to be the most effective among various rice varieties. The identification of bioactive compounds was then carried out by an isotopic signature profile method using the characteristic isotopic ion cluster generated by the mixture of HNE: ²H₅-HNE mixed at a 1:1 stoichiometric ratio. An in-house database was used to obtain the structures of the possible bioactive components. The identified compounds were further confirmed as HNE sequestering agents through HPLC-UV analysis.     

Studies on the early development of zygotic and synergid embryo and endosperm in polyembryonic rice ApIII

A morphological, cytological and embryological investigation was conducted on the early development of embryo and endosperm in polyembryonic rice (Oryza sativa L.) ApIII. We found that the percentage of single-, twin- and triple-seedlings from mature caryopses was 82.4–85.6%, 11.3–14.6% and 2.0–3.8%, respectively. From twin-seedlings one of the plants and in the triple-seedlings usually two seedlings were very weak having a mortality of about 50–60% and over 95%, respectively, and most of the dead seedlings were haploid. In addition, among 674 young caryopses the percentage of single-, double- and triple-embryo sacs was 77.60%, 18.10% and 4.30%, respectively. The development of both embryo and endosperm was observed in the embryo sacs of 653 young caryopses, while embryo development occurred in absence of endosperm in the embryo sacs of 21 ones. Furthermore, after pollen tube penetration, frequently one, rarely two, additional embryos arise via apogamy from the typical specialized synergid of normal egg apparatus with a collapsed cap-neck region that had a damaged filiform apparatus at the micropylar end. Finally, the formation of a strikingly degenerated endosperm cell region is a specialized functional structure that serves for the active transport of metabolites from endosperm to the developing embryo. Taken together, these results suggest that synergid apogamy seems to be the unique reason of polyembryony, poor growth and high mortality of many seedlings may be due to haploidy, and high genetic stability of polyembryony occurs in rice ApIII.     

Quality Evaluation of Rice Crackers Based on Physicochemical Measurements

The processing suitability as a material for rice crackers was characterized in the present study, based on physicochemical measurements and sensory testing of high-quality premium rice, low-amylose rice, Japonica-Indica hybrid rice, and red rice as the rice cultivar samples. Puffed rice crackers were prepared and the relationship between the physicochemical properties of the rice grains and the quality of the resulting products was investigated. It was possible to estimate the physical properties of a rice cracker by using multiple-regression analysis based on the chemical components, pasting properties and physical properties of the constituent rice. A formula for estimating the amylose content of the constituent rice was developed from the results of physicochemical measurements of the rice crackers. We assayed the quality of commercial rice crackers and examined the deterioration during the storage by measuring the physicochemical properties. The hardness and fat acidity of crackers increased markedly during storage for 20 d at 35 °C. The novel method of a one-bite test with a Tensipresser was useful to assay the quality of a rice cracker and made it possible to evaluate the quality deterioration of the rice cracker during storage.     

Phenotypic diversity of 188 rice embryo mutants

We have identified 188 embryo mutants of rice and characterized them into six groups based on their phenotypes: (1) embryoless in mature seed, (2) deletion of embryonic organ(s), (3) abnormal position of embryonic organs, (4) abnormal embryo size, (5) defect in organ morphology, and (6) variable abnormal phenotypes in spite of single mutations. Three types of organless mutants are obtained: small globular embryo, club-shaped embryo, and large embryo. Although 12 shootless mutants derived from at least three loci are identified, only three radicleless mutants are recovered, which produce normal adventitious roots after germination. In reduced embryo mutants, every embryonic organ is reduced, in contrast to giant embryo mutants in which only scutellum is enlarged. Considerable number of mutants are categorized into (5) and (6) in the above. These diverse embryo mutants would serve as promising materials for genetic study of embryogenesis. © 1995 Wiley-Liss, Inc.     

Physicochemical properties of Shiga toxigenic Escherichia coli

AIMS: To investigate the physicochemical surface properties, such as cellular surface charge, hydrophobicity and electron donor/acceptor potential of a selection of Shiga toxigenic Escherichia coli (STEC) isolates grown in broth and agar culture. METHODS AND RESULTS: Cellular surface charge was determined using zeta potential measurements. Hydrophobicity of the isolates was determined using bacterial adhesion to hydrocarbons assay, hydrophobic interaction chromatography and contact angle measurements. Microbial adhesion to solvents was used to determine the electron donor/acceptor characteristics. No differences of surface charge measurements were found between broth and agar grown cultures. Isolates belonging to serogroup O157 and serotypes O26:H11 and O111:H- were significantly (P < 0.05) less negatively charged than other STEC serotypes tested. All strains were hydrophilic with most methods and demonstrated a lower hydrophobicity in agar culture compared with broth culture. All strains demonstrated a strong microbial adhesion to chloroform indicating that STEC possess an electron donor and basic character. A relationship between serogroup O157 and other STEC serotypes was apparent using principal-component analysis (PCA). CONCLUSIONS: Combining the results for physicochemical properties using PCA differentiated between strains belonging to the O157 serogroup and other STEC/non-STEC strains. PCA found similar results for broth and agar grown cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: Particular serotypes of STEC possess similar physicochemical properties which may play a role in their pathogenicity or potential attachment to various surfaces.     

不同品种水稻秸秆的理化特性及酶解产糖的研究

本研究以不同品种水稻秸秆为原料,测定分析了三大主要组分纤维素、半纤维素和木质素含量及理化特性的差异,并分析对比了经碱预处理后酶解及直接酶解的产糖率差异。利用X-射线衍射仪测定分析了结晶度和晶粒尺寸的异同,红外光谱仪定性评估了特定基团的差异,扫描电镜观察分析了表面形态结构的差异。综合考虑理化特性和酶解产糖率结果,与a(常规水稻黄华占)相比,5种不同品种的超级杂交水稻秸秆中,b(杂交水稻Y两优1)、c(杂交水稻隆两优2010)和f(杂交水稻Y两优143)三个品种的秸秆材料比较适合作为酶解产糖的原材料。     

不同稻作年限下土壤微生物学性质和线虫群落特征的变化

红壤地区旱地改水田后随稻作年限的增加土壤性质会发生改变,但缺乏对百年尺度内土壤动物群落特征变化的了解.本研究选取了旱改水后1 yr、10 yr、20 yr、50 yr和100 yr五个时序的田块,研究了稻作土壤微生物学性质及线虫群落特征的变化.结果表明,随着稻作年限的延长,土壤微生物生物量碳氮、基础呼吸、矿质氮、速效磷、线虫数量及线虫属数均随稻作时间增长而逐渐上升,在50 yr均达到显著水平(P＜0.05),在50-100 yr变化渐缓或有所下降.线虫群落中植食者的比例显著上升(P＜0.05),捕食/杂食者的比例有所下降但差异不显著.线虫通道指数也随稻作年限的增加而逐渐增长(P＜0.05),表明土壤食物网结构趋向于细菌通道.稻作年限对线虫群落成熟度指数和结构指数的影响并不一致.总之,土壤微生物学性质和线虫群落在旱改水50 yr时土壤各项性质均达到较高水平,随稻作年限的继续延长呈现稳定趋势.     

白木通种子油的理化特性及制备生物柴油的研究

以白木通种子为实验材料,索氏提取法提取种子油,GC-MS测定脂肪酸组成,国标法测定理化性质,运用响应面法对碱催化白木通种子油酯交换制备生物柴油工艺进行优化。结果表明:白木通种子油含有5种脂肪酸,其中油酸含量最高,硬脂酸次之。白木通种子油的得率、含水量、碘值、酸值、皂化值、过氧化值、凝固点、闪点和冷滤点分别为32.76%、0.36%、67.89 g/100 g、8.85 mg KOH/g、235.03 mg KOH/g、47.08 mmol/kg、-12℃、215℃和-7℃。优化的生物柴油制备工艺为:反应时间80 min,醇油摩尔比6.7∶1,催化剂用量1.3%(按反应体系总质量计算)。白木通种子含油率高,可作为藤本油料作物开发利用。     

三七总皂苷原粉和超微粉的理化性质比较研究

通过对药用植物三七总皂苷原粉和超微粉的粉体粒度、电位、显微结构、红外光谱、溶解速度这几项理化性质的研究,判定两种粉体的优劣,为三七总皂苷超微粉的市场推广提供依据。实验结果表明,三七总皂苷原粉经纳米化处理后成为三七总皂苷超微粉,其化学结构没有发生变化,但显微结构从条状的晶体变为由纳米球紧密排列的不规则形态,其粉体平均粒径也从1 122.4 nm缩小到153.4 nm,完成了从微米到纳米的转变,其水溶液也变为稳定的胶体溶液。运用高效液相色谱法,在模拟人体环境的条件下,发现三七总皂苷超微粉比三七总皂苷原粉早1 min完全溶解。说明三七总皂苷超微粉比三七总皂苷原粉颗粒更小,更易溶于水,更易与人体吸收。     

Physicochemical properties of pretreated poplar feedstocks during simultaneous saccharification and fermentation

Physicochemical properties of native and dilute acid pretreated (0.6% H₂SO₄, 10 min, and either 170°C or 180°C) poplar were investigated before and during simultaneous saccharification and fermentation (SSF). SSF duration was 5 days and employed Trichoderma reesei cellulases and Saccharomyces cerevisiae fermentation. Chemical composition (glucan, xylan, lignin), enzyme-accessible surface area (based on solute exclusion), crystallinity index, particle size distribution, particle shape, and enzyme adsorption (cellulase, β-glucosidase) were compared to cellulose conversion. Cellulose conversion varied from 8% for native poplar to 78% for the 180°C-pretreated poplar. The physicochemical properties of native poplar changed little during SSF. In contrast, the physicochemical properties of the 180°C-pretreated feedstock changed markedly. Enzyme-accessible surface area and β-glucosidase adsorption increased by 83% and 65%, respectively, as cellulose was removed from the feedstock. Crystallinity index and particle size (large fraction) decreased by 65% and 93%, respectively. Cellulase adsorption per unit weight increased initially (+45%) followed by a slight decrease (−13%). The same trends were observed, although to a lesser extent, for 170°C-pretreated feedstock.     

Physicochemical measurements of Japonica rice cultivars in Heilongjiang Province

We here characterized 27 japonica rice cultivars grown in Heilongjiang province and evaluated the relationship among their iodine absorption curve, physical properties, and ratio of 13 kDa prolamin. We developed the novel estimation formulae for ratio of 13 kDa prolamin and overall hardness (H2) with the use of A_λmax and λmax.     

大米辅料对啤酒酿造的影响

我国啤酒酿造主要使用大米作为辅料,我国大米品种繁多,其品质有较大差异。贮存期间,大米的品质发生变化,不同品质的大米,不同品种的大米对啤酒酿造和啤酒特性有明显的影响。     

Development of formulae for estimating amylose content and resistant starch content based on the pasting properties measured by RVA of Japonica polished rice and starch

We searched for the easy and simple method to measure the novel indicators which reflect not only AAC, but also (RS) based on pasting properties using RVA. Novel indexes such as SB/Con and Max/Fin (Maximum viscosity/Minimum viscosity) ratios had a very high correlation with proportion of intermediate and long chains of amylopectin; Fb₁₊₂₊₃ (DP ≧ 13). In Japonica polished rice, estimation formulae for AAC and RS content were developed using novel indexes based on pasting properties by RVA, and these equations showed determination coefficients of 0.89 and 0.80 for calibration and 0.71 and 0.75 for validation test. We developed the estimation formulae for AAC and RS content for Japonica starch samples. These equations showed determination coefficients of 0.86 and 1.00 for calibration and 0.76 and 0.83 for validation test, which showed that these equations can be applied to the unknown rice samples.     

微胶囊叶黄素理化性质及其稳定性研究

本文研究了微胶囊叶黄素产品的理化性质及其在光、热、pH值及氧气条件下的稳定性。结果表明,微胶囊叶黄素含水率为3．0％、密度0．39g／cm^3、粒径8—10μm、溶解度90s;叶黄素经微胶囊化后可明显提高叶黄素的光稳定性和热稳定性,减弱了pH值的影响和氧气对叶黄素的氧化降解。     

17Beta-estradiol induces nuclear translocation of CrkL at the window of embryo implantation

Crk family adaptors are widely expressed and mediate the timely formation of signal transduction protein complexes upon a variety of extracellular stimuli, including various growth and differentiation factors. The window of implantation is the favorable time period when the uterus develops a receptive approach to the invading embryo. Various signaling cascades are likely to become active at the window of implantation both in the uterus and the embryo. This helps create maternal embryo dialogue leading to successful embryo implantation. In this study we report for the first time the presence and nuclear translocation of the adaptor molecule CrkL both in the uterine and embryonic partners at the window of implantation. We also report that estrogen, which initiates and guides crucial changes in the uterus and the embryo at the window of receptivity, causes a massive surge in the expression and subsequent nuclear translocation of CrkL. We have also identified the existence of one LXXLL motif in the CrkL amino acid sequence and a single LXD is sufficient for activation by the estrogen receptor. This is suggestive that CrkL can bind to estrogen receptors and act as a coactivator.     

High-frequency plant regeneration from coleoptile tissue of indica rice (Oryza sativa L.)

Summary An efficient method was established for high-frequency embryogenic callus induction and plant regeneration from 3-,4-, 5- and 7-d-old coleoptile segments of Indica rice (Oryza sativa L. cv. Kasturi), Compact and friable callus developed from the cut ends and also on the entire length of the coleoptile segments cultured on Murashige and Skoog (MS) basal medium (1962) supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D, 4.50–18.0 μM), kinetin (2.32 μM) and sucrose (3%, w/v). High frequency embryogenic callus induction and somatic embryo development was achieved when embryogenic calluses were transferred to MS medium supplemented with 2.25 μM 2,4-D, 2.32 μM kinetin, 490 μM L-tryptophan and 3% (w/v) sucrose. Plant regeneration was achieved by transferring clumps of embryogenic callus onto MS medium containing 2.85 μM indole-3-acetic acid (IAA), 17.77 μM 6-benzylaminopurine (BA) and 3% (w/v) sucrose. Histological observations of embryogenic calluses revealed the presence of somatic embryos and also plant regeneration via multiple shoot bud formation. Three, 4- and 5-d-old coleoptile segments showed a significantly (P<0.05) higher frequency of plant regeneration and mean number of plantlets per explant in comparison to 7-d-old coleoptile segments. The highest frequency (73.5%) of plant regeneration and mean number of plantlets (11.9±1.0) was obtained from 4-d-old coleoptile segments. Regenerated shoots were rooted on MS basal medium containing 4.92 μM indole-3-butyric acid (IBA) and plants were successfully transferred to soil and grown to maturity.     

Automation of somatic embryo production

Automation could enhance the use of somatic embryogenesis for micropropagation in two ways: as effective tools for research on somatic embryogenesis, and for improving the efficiency of embryo production by reducing labor costs. Processes expected to be automated for somatic embryo production are: (1) evaluation of embryogenic cultures, (2) embryo development, (3) harvesting, (4) post-harvesting (pre-delivery) processes for enhancing conversion and preparing for delivery. In this review, the techniques related to the automation of each process are introduced and discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Influence of Physicochemical Properties of Rice Flour on Oil Uptake of Tempura Frying Batter

The physicochemical properties of rice flour and wheat flour influenced the oil uptake of tempura frying batter. Rice flour was better than wheat flour in the overall quality and crispness of the fried tempura batter. Rice flour resisted oil absorption more than wheat flour, and a higher level of apparent starch amylose and higher consistency/breakdown ratio of the pasting properties led to a lower oil uptake of the batter. Super hard EM10 rice showed the highest apparent amylose content and higher consistency/breakdown ratio than the other flour samples, the batter from EM10 revealing the lowest oil content after frying among all the batters examined. The apparent amylose content, consistency/breakdown ratio and oil absorption index are proposed as useful guides for oil absorption when frying from among the physicochemical properties that influence the oil content of fried batter. Our proposal for the “oil absorption index” could be a simple, although not perfect method for estimating the oil content of batter flour.