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排序方式: 共有499条查询结果,搜索用时 15 毫秒
31.
32.
Woffenden HM Ames JM Chandra S Anese M Nicoli MC 《Journal of agricultural and food chemistry》2002,50(17):4925-4933
Pale malts were prepared using standard and rapid kilning regimes that differed in the temperature and moisture profiles in the kiln. Samples were taken over the last 9 h of kilning, that is, at 18, 20, 22, 25, and 27 h. Antioxidant activity, assessed by redox potential, scavenging of the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS*+), and ferric reducing/antioxidant power (FRAP), increased at moisture levels below 6.7% for both regimes. The 27 h malt exposed to the rapid regime (moisture content of 4.8%) had a higher activity than the 27 h standard regime sample (moisture content of 4.8%). None of the malts scavenged oxygen. Pro-oxidant activity profiles were different for the malts obtained using each regime and, at 27 h, the rapid procedure gave malt with higher activity. Levels of (+)-catechin and ferulic acid (the most abundant phenolic compounds identified) generally increased as the moisture content of malt fell below 6.7%. Differences in antioxidant and pro-oxidant activities of the 27 h malts are partly attributed to the Maillard reaction, as evidenced by lower L* and higher b* values and higher levels of Maillard-derived flavor compounds, in the sample obtained by the rapid procedure. Levels of lipid-derived flavor compounds were significantly higher after 27 h of kilning using the rapid procedure. 相似文献
33.
The present study was undertaken in five major forest types (dominated by Quercus semecarpifolia, Quercus floribunda, Acer acuminatum, Abies pindrow and Aesculus indica, respectively) between 2400 and 2850 m a.s.l. in a moist temperate forest of the Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim was to assess the variation in composition and diversity in different vegetation layers, i.e., herb, shrub and tree, among these five forest types. Diversity indices, such as the Shannon-Wiener diversity index, density, total basal cover, Simpson’s concentration of dominance index, Simpson’s diversity index, Pielou’s equitability, species richness, species heterogeneity and β-diversity, were calculated to understand community structures. Dominance-diversity curves were drawn to ascertain resource apportionment among various species in different forest types. 相似文献
34.
Brovelli EA Rua D Roh-Schmidt H Chandra A Lamont E Noratto GD 《Journal of agricultural and food chemistry》2005,53(21):8156-8161
A phenological study was conducted to determine the impact of harvest maturity on the immune-modulating properties of Echinacea purpurea. The aerial parts of this plant were collected during seven stages of development and were assayed for a common botanical marker for this species, cichoric acid. Plants of selected development stages were also assayed for total polysaccharides and compared for their immune-modulating effects on the THP-1 monocyte/macrophage cell line by means of a gene expression study. Although the concentration of cichoric acid did not change significantly during the course of the study, stage 1 (advanced vegetative) had the highest concentration of total polysaccharides and exhibited the most potent induction activity on immune-modulating cytokines such as interferon-gamma and tumor necrosis factor-alpha. These findings suggest that the use of gene expression may be an effective tool not only to standardize botanical extracts but also to optimize harvest time. 相似文献
35.
Takashi Ozawa Chandra Prasad Risal Ryoko Yanagimoto 《Soil Science and Plant Nutrition》2005,51(6):917-920
The contribution of an earthworm species ( Amynthas vittatus ) to the increase of the nitrogen content of soil was examined. Three specimens of adult earthworms were introduced into 300 g of soil (Gray Lowland soil, silty clay) supplemented with 1% carboxymethyl cellulose in a container and incubated for 32 d at 22°C in the dark. The contents of total-N, NH4 -N and NO3 -N, and the population of aerobic nitrogen-fixing bacteria in soil significantly increased after incubation with the earthworms, while the natural abundance of 15 N (δ15 N) in soil decreased. The amount of nitrogen in the earthworms did not decrease during the incubation in the microcosm. Both acetylene reduction activity of the microcosm and incorporation of 15 N to soil from atmospheric 15 N2 were significantly enhanced by the introduction of the earthworms into soil, though the observed increment of nitrogen in soil was much higher than the estimated one based on the nitrogen-fixing activity. The results obtained in the present study indicated that the earthworms increased the nitrogen content of soil, presumably due to the enhancement of the nitrogen-fixing activity of the soil from the microcosm by the earthworms. 相似文献
36.
Dagobiet Morales-Garcia Katrine A. StewartPhilippe Seguin Chandra Madramootoo 《Agricultural Water Management》2011,98(5):893-898
The effect of supplemental saline (2.5 dS m−1) drip irrigation and black polyethylene mulch on two cultivars of bell peppers (Capsicum annuum L.) was investigated under field conditions using a randomized complete block design with split-split plot restriction. The research included six irrigation treatments (main plots): (i) non-saline irrigation control applied throughout growth (None), (ii) saline irrigation from transplanting until formation of the first fruit set (S1S2), (iii) saline irrigation from transplanting until appearance of the first flower and from first harvest to final harvest (S1S4), (iv) saline irrigation from appearance of the first flower to first harvest (S2S3), (v) saline irrigation from fruit set to final harvest (S3S4), and (vi) saline irrigation throughout growth (All); two mulch treatments (subplots): (i) black mulch and (ii) bare soil; and two bell pepper cultivars (sub-subplots): (i) Early Sunsation and (ii) Red Knight. Production of fully ripened fruits was higher in mulched plants regardless of saline irrigation treatments. In humid areas with non-saline soil, supplemental saline drip irrigation could be used with black polyethylene mulch to save water while maintaining fruit production. 相似文献
37.
38.
Mary Elizabeth K. Gnanambal K. C. Ramya Devi P. Hareesh Chandra Edward J. K. Patterson 《Phytoparasitica》2011,39(2):121-127
The current study is based on the screening of novel insecticides from new sources that have not being exploited hitherto.
The major objectives of this research work were to extract marine molluscs, Lambis lambis, Trochus radiatus and Chicoreus ramosus, from Tuticorin coastal waters using different solvents to test their insecticidal properties and partially purify the active
components. The ethyl acetate extracts of L. lambis and T. radiatus showed 100% mortality of Sitophilus oryzae, at a concentration of 200 μg ml−1. The LC50 values for ethyl acetate extracts of L. lambis, T. radiatus and C. ramosus were found to be 67.08, 348.86 and 571.42 μg ml−1, respectively. With regard to bacterial metabolites, at a concentration of 200 μg ml−1 the ethyl acetate extract of A3 was able to elicit an activity of 40% and that of strain A1 – 20%. The LC50 values of the bacterial metabolites were also investigated. Upon chromatographic separation of active ethyl acetate extracts
of T. radiatus, the 100% methanol column-purified fraction was found to have an activity of 30% at a concentration of 10 μg against S. oryzae. The purity of the partially pure active compound was observed to be 72.78% on analysis with high pressure thin layer chromatography. 相似文献
39.
Naturally derived micelles for rapid in vitro screening of potential cholesterol-lowering bioactives
Kirana C Rogers PF Bennett LE Abeywardena MY Patten GS 《Journal of agricultural and food chemistry》2005,53(11):4623-4627
A high plasma cholesterol level, especially low-density lipoprotein cholesterol, indicates increased risk of cardiovascular diseases. Plasma cholesterol levels are influenced by diet and cholesterol biosynthesis, uptake, and secretion. Cholesterol uptake involves solubilization into complex phospholipid spherical bodies termed micelles that facilitate the transport of lipids through the gut brush border membrane into enterocytes. In vitro assays reported to date to determine potential cholesterol-lowering effects of various compounds require artificial micelle preparations that are elaborate and time-consuming to prepare. The aims of this study were to compare the efficacy of artificially prepared micelles with naturally derived micelles from pig's bile and to test their ability to assess potential inhibitors of cholesterol uptake. The suitability of pig's bile-derived micelles was tested both at the level of the micelle and at cellular uptake using cultured Caco-2 cells. Known cholesterol uptake inhibitors at the micelle (green tea catechins) and at the Caco-2 cell (beta-lactoglobulin-derived peptide, IIAEK) were used as reference inhibitory compounds. It was concluded that pig's bile was a rapid, reproducible, convenient, and cost-effective source of micelles for cholesterol micelle solubility and cellular uptake assay systems and is suitable for screening purposes focused on identifying potential cholesterol-lowering agents. 相似文献
40.
S. K. Gupta Anamika Tewari Richa Srivastava R. C. Murthy Saurabh Chandra 《Water, air, and soil pollution》2005,163(1-4):293-302
Vermicomposting of fly ash has been attempted, using red earthworm, Eisenia foetida. Fly ash, which was obtained from thermal power station, was mixed with cowdung in different proportions (20, 40, 60 and 80%). These mixtures were used as feed for earthworms, and after 30 days, vermicast recovery, worm zoomass and numbers of juveniles produced were recorded. A total of six runs each of 30 days were conducted during the whole study. Concentrations of heavy metals in different mixtures of fly ash–cowdung, before and after vermicomposting and in the earthworms used in the study were also estimated. Results show maximum output of vermicasts and maximum number of juveniles produced was in reactors with 40% fly ash while maximum weight gain by earthworm was in 20% fly ash vermireactors. Performance of vermireactors up to 60% fly ash was more or less similar but at 80% fly ash, there is a marked reduction in overall performance of the reactors. Chemical analysis of different samples of fly ash–cowdung mixtures prior to vermicomposting revealed high concentrations of zinc, chromium, lead, nickel and copper. Chemical analysis of vermicomposted samples showed 30–50% reduction in heavy metals up to 60% fly ash and 10–30% reduction in 80% fly ash. Metal analysis of earthworms revealed considerable bioaccumulation of heavy metals in their body. The Present study indicates the feasibility of E. foetida for mitigating the toxicity of metals and up to 60% fly ash–cowdung mixtures can be used for sustainable and efficient vermicomposting. 相似文献