Effect of Different Drying Treatments and Solvent Ratios on Phytochemical Constituents of Ipomoea aquatica and Correlation with α-Glucosidase Inhibitory Activity

Ipomoea aquatica is an aquatic plant that is widely consumed in Southeast Asia as a vegetable. In this study, the influence of various ethanol ratios (0, 20, 50, 80, and 100%) as an extraction solvent and different drying methods including air drying, sun drying, and oven drying on phytochemical constituents of I. aquatica was investigated using a proton nuclear magnetic resonance-based metabolomics approach. The effect on α-glucosidase inhibitory activity and total phenolic content was also examined. Clear discrimination was observed between different ethanol ratios and different drying processes by principal component analysis. The highest α-glucosidase inhibitory activity was observed for absolute ethanol extract from the oven drying method with IC₅₀ value of 204.0 ± 59.0 µg/mL and total phenolic content value of 22.0 ± 0.7 µg gallic acid equivalent/mg extract. Correlation between the α-glucosidase inhibitory activity and the metabolite were analyzed using a partial least square analysis. The metabolites that are responsible for the activity were quercetin derivatives, chlorogenic acid derivatives, sucrose, and fructose. This study highlights the basis for future investigations of I. aquatica as a source of food that has the potential for nutraceutical enhancement and as ingredient in medicinal preparation.     

食盐浓度对熟腌茭白理化性质及品质的影响

以茭白为原料,研究了不同食盐浓度腌制茭白其发酵过程中理化指标(p H、总酸、盐度、亚硝酸盐含量和氨基酸态氮)和微生物指标(细菌、乳酸菌总数)的变化,并对成品的色泽、质地、挥发性风味物质进行了分析。结果表明,3%、5%和8%食盐浓度下腌制的茭白p H分别为3.73、3.18和3.48,酸度分别为13.77、23.67和17.05 g/kg,平衡盐度分别为1.21%、2.51%和3.42%,"亚硝峰"值分别为7.86、11.6和11.79 mg/kg,氨基酸态氮含量分别为0.012、0.027和0.048 g/m L,细菌和乳酸菌数均稳定在107CFU/m L。腌制后茭白的色泽和质地都会有所改变,食盐浓度越低其失色越严重,腌制后茭白的硬度低于新鲜茭白,咀嚼性和内聚性随食盐浓度的升高而增大;三种食盐浓度腌制后茭白均检测到39种挥发性化合物,主要挥发性风味物质为乙醇、2,3-丁二醇、乙酸、乙酸乙酯和苯甲醛等。建议茭白腌制初始食盐浓度为5%。     

水生植物净化规模化猪场厌氧发酵水的试验研究

试验采用凤眼莲、水蕹菜、生菜净化处理厌氧发酵后的出水,初水CODcr浓度为170～230 mg/L,结果表明,在这3种水生植物的对比试验中,生菜对废水CODcr去除率最高,平均去除率为64%;水蕹菜对氨氮、硝态氮、磷和浊度的降解率最高,平均降解率分别为98.37%,24.95%,91.45%,95.31%.经过生菜处理后的废水颜色为白色,而其它均为浅黄色.经过为期一个月的静态试验表明所有出水均达到二级出水标准.通过试验认为水生植物净化低浓度猪场废水的作用除了植物本身对水体中氮、磷等营养的吸收外还应包括植物根系对悬浮物和胶体等的吸附作用以及胶体凝聚沉降的作用.     

Flooding and Surface Connectivity of Taxodium‐Nyssa Stands in a Southern Floodplain Forest Ecosystem

An understanding of the factors controlling the permanent and episodic links between the main stem of a river and the ecosystems of its alluvial floodplain is necessary for evaluating the influence of modern river processes on floodplain ecology and habitat diversity and for the successful implementation of flow regimes that meet human needs for water in a manner that sustains the ecological integrity of affected systems. In this study, we examined relationships between river hydrology and lateral hydrological connectivity, which is crucial to directing fluxes of water, material, and organisms into and across a floodplain. We did so by translating measures of river discharge for the Congaree River into high resolution maps of flood conditions for the floodplain at Congaree National Park using a 2D flood inundation model. Utilizing a graph network approach, we then analyzed the connectivity of a key wetland ecosystem, Taxodium‐Nyssa forested swamps, to the main stem river and to each other under different flows. Our results underscore that floodplain connectivity is initiated at sub‐bankfull discharges and does not depend on levee overtopping, while also clarifying that various sources of connectivity are triggered at different flow levels in specific reaches. Further, our findings demonstrate the sensitive and non‐linear response of floodplain connectivity to river flows and provide useful information to facilitate the management of flood processes in the Congaree River watershed. Copyright © 2014 John Wiley & Sons, Ltd.     

Isolation of a free radical‐scavenging antioxidant from water spinach (Ipomoea aquatica Forsk)

Ipomoea aquatica Forsk, a green leafy vegetable that is a rich source of vitamins and amino acids with many health benefits, has been explored for the isolation and identification of its bioactive compounds. Activity‐guided repeated fractionation of a methanol extract on a silica gel column followed by an XAD column yielded a compound that exhibited antioxidant activity with an EC₅₀ value of 83 ± 1.02 µg ml^?1 reaction mixture. It also showed very strong lipid peroxidation‐inhibitory activity in a liposome model system with an EC₅₀ value of 72.2 ± 0.9 µg ml^?1. However, it showed negligible metal‐chelating activity. Based on UV, 2D nuclear magnetic resonance and gas chromatography/mass spectrometry studies, the compound was tentatively identified to be 7‐O‐β‐D ‐glucopyranosyl‐dihydroquercetin‐3‐O‐α‐D ‐glucopyranoside. This is the first report on the antioxidant properties of I aquatica leaf extracts. Copyright © 2005 Society of Chemical Industry     

贮藏温度对空心菜保鲜效果的影响

以空心菜为对象,采用感官评价、VC、低场核磁共振分析水分迁移等为指标研究贮藏温度(0,5,10,15℃)对空心菜保鲜效果的影响。研究表明,0℃贮藏,空心菜易发生冷害,15℃贮藏,空心菜衰老加快,均不利于贮藏。5,10℃贮藏,空心菜的感官品质、叶绿素含量、VC含量等品质指标维持相对较好,贮藏8d时各指标均保持较好。而且空心菜在5℃贮藏后期(第10天后)也会发生一定的冷害,品质下降较快,在10℃贮藏,对空心菜多数品质指标(除了菌落总数)的维持均优于在5℃贮藏的。     

水蕹菜总黄酮含量的测定

以芦丁标准品为对照,采用分光光度法在510nm处测得水蕹菜中总黄酮的含量为29.739mg/g。测定中,吸收度A与芦丁的质量浓度C在10.0-50.0μg/mL的范围内呈现良好的线性关系,平均回收率为96.955%。操作方法简便易行、结果准确、灵敏度高、重现性好,为水蕹菜药用价值的开发提供了一定的科学依据。     

Contents of Al,Cu, Fe,and Mo in Phalaris aquatica and Trifolium subterraneum grown on an unamended and amended gold-mine tailings-storage facility in central-western New South Wales,Australia

Phalaris aquatica and Trifolium subterraneum grown on a tailings-storage facility (control) and tailings-storage treated with either topsoil or biosolids in a gold–copper mine were analysed for Al, Cu, Fe, and Mo contents. Soil samples from the treatments were also tested for these metals and soil properties. Results indicated that higher levels of metals occurred in T. subterraneum than in P. aquatica; metal contents in both taxa were significantly greater in the control, and higher metal contents occurred in plants tested in May 2008 (autumn) compared with October 2008 (spring). A strong relationship existed between Cu, Fe, and Mo contents in T. subterraneum and Al content in the tested soils. A significant relationship was also observed between Al content in T. subterraneum and K, Na, and SO₄ levels in the soils. We recommend that tailings soil be amended with either topsoil or biosolids before grazing livestock to reduce the risk of either mineral deficiencies or toxicities.     

水生植物滤床对猪场养殖废水的深度处理研究

为探究水生植物滤床系统深度处理畜禽废水的效能,采用水蕹菜作为滤床植物,在不同水力负荷下处理养猪场废水的二级出水。试验于温室内进行,控制进水COD和NH4+-N、TP的质量浓度分别为200 mg/L和120、10 mg/L,水力负荷分别为0.025、0.050、0.075m3/(m2.d),温度为25～30℃。经过3个月的连续运行,结果表明,在水力负荷0.025m3/(m2.d)时有最好的废水处理效果,对TN、TP、NH4+-N和COD的去除率分别达到39.7%、57.4%、67.9%和54.3%。其中,氮素的去除主要通过硝化-反硝化途径去除,植物吸收作用不及1%,而总磷的减少除了植物根系的截留作用,植物的同化作用也占有较大比重。水生植物滤床在合适的水力负荷下能够有效的深度净化猪场养殖废水,同时可利用水蕹菜回收部分氮磷,具有一定的经济效益。     

ETHANOL FERMENTATION OF VARIOUS RED RICES WITHOUT COOKING

With various red rices as raw material, fermentation without cooking was allowed to proceed at pH 4.0 and 30°C for 4 d for production of novel alcoholic beverages. Ethanol fermentation was achieved with various rice grains. In particular, uncooked wild-rice (Zizania aquatica) is reported now for the first time as being used for ethanol fermentation. The final concentration of ethanol achieved during fermentation was 8.8–9.3% (v/v). Rice wine made from aromatic red rice (Oryza sativa var. Indica, Tapol) had a wine-like red color. It was rich in a fruity aroma and had a characteristic sour taste, as revealed by organoleptic testing. Volatile substances formed have been analysed by gas chromatography. Rice wine made from black rice (Oryza sativa var. Indica) also had a wine-like red color and a sour taste. By contrast, rice wines made from red rice (Oryza sativa var. Japonica) and wild-rice were faintly yellow in color and had a sake-like and a somewhat green tea-like flavor, respectively. Although the red pigments of the aromatic red rice and black rice were solubilized during uncooked ethanol fermentation, the pigments of red rice and wild-rice were insoluble and not available as material for brewing of red-colored alcoholic beverages. Aromatic red rice appears to be a suitable material for the production of a wine-like alcoholic beverage.