Comparison of physicochemical, binding, and antibacterial properties of chitosans prepared without and with deproteinization process     

No HK  Lee SH  Park NY  Meyers SP 《Journal of agricultural and food chemistry》2003,51(26):7659-7663

Physicochemical, binding, and antibacterial properties of chitosans prepared without and with deproteinization (DP) process (5, 10, 15, and 30 min at 15 psi/121 degrees C) were compared. Chitosan from DP 0 min had comparable nitrogen content, lower degree of deacetylation and solubility, but higher molecular weight and viscosity than chitosans from DP 5-30 min. The latter four chitosans showed differences only in molecular weight. Deproteinization treatment resulted in slightly decreased L values and increased a and b values compared with those of DP 0 min. Chitosan from DP 0 min had comparable water and fat-binding capacity (FBC) except for chitosan from DP 15 min, which had a higher FBC but lower dye-binding capacity than those of the four chitosans from DP 5-30 min. The antibacterial activities of chitosans against seven different bacteria showed that the inhibitory effects varied with the deproteinization time and the particular bacterium.  相似文献   

Effect of methanol/acetone/water extraction and enzymatic hydrolysis on the nutritional value of unheated rapeseed proteins     

Monique Lacroix  Jean Amiot  Foued Cheour  Joël De La Noüe  Gilles Goulet  Germain J. Brisson 《Plant foods for human nutrition (Dordrecht, Netherlands)》1988,38(4):343-353

The objective of this work was to study the effect of the extraction of phenols by methanol/acetone/water and proteolysis (pepsin 1 hour; trypsin 2 hours) on the nutritional characteristics of unheated rapeseed protein as measured by weight gain, protein intake, net protein ratio, apparent digestibility and absorbed protein. The effect of proteolysis of the methanol/acetone/water extracted rapeseed protein, and the effect of mixing the methanol/acetone/water extract back with the extracted rapeseed protein was also studied. Extraction of phenolic compounds from rapeseed flour significantly improved weight gain, protein intake, net protein ratio and absorbed protein value. However, the mixing of phenolic extract with the extracted rapeseed protein did not appear to have a significant effect.Enzymatic hydrolysis (1 hour with pepsin and 2 hours with trypsin) of the raw material significantly improved the weight gain and protein intake. The combined methanol/acetone/water extraction and protein hydrolysis treatments were beneficial on all nutritional quality parameters of rapeseed protein. These results suggest that the protein-bound phenolic compounds, rather than the free phenolic compounds contribute mainly to the decrease in the nutritional values of proteins associated with phenolic compounds in raw flour before extraction.  相似文献   

<Emphasis Type="Italic">Posidonia oceanica</Emphasis> meadow: a low nutrient high chlorophyll (LNHC) system?     

Sylvie?GobertEmail author  Noémie?Laumont  Jean-Marie?Bouquegneau 《BMC ecology》2002,2(1):9

Background  

In spite of very low nutrient concentrations in its vicinity – both column and pore waters-, the Posidonia oceanica of the Revellata Bay displays high biomass and productivity. We measured the nutrient fluxes from the sediment into the water enclosed among the leaf shoots ("canopy water") to determine if it is possible source of nutrients for P. oceanica leaves.  相似文献   

Overwintering of winter cereals in Hungary in the case of global warming     

Ottó Veisz  Noémi Harnos  László Szunics  Tibor Tischner 《Euphytica》1996,92(1-2):249-253

Summary Under phytotronic conditions investigations were made on the effect of important environmental factors, such as temperature, water and an increasing concentration of atmospheric CO₂, on the hardening of young cereal plants.In all the varieties derived from the major wheat growing regions of the world the hardening process was favourably influenced by a doubling of atmospheric CO₂ content, so that a significantly larger number of plants survived the frost test than for plants of the same variety raised under normal conditions.A reduction in freezing temperature and an increase in soil moisture content caused a slight reduction in survival % for varieties with excellent frost resistance and a great reduction for those with medium or poor frost resistance.Predictions suggest that in Central Europe, as the result of global climatic changes, there will be a reduction in the quantity of winter precipitation, a considerable rise in winter temperatures and an increase in atmospheric CO₂ concentration. Judging by the experimental results, these changes could improve the overwintering of winter cereals; at the same time, however, a number of factors (mainly the reduction of precipitation) leading to yield losses must be expected during the vegetation period.  相似文献   

ON THE CRITICAL TEMPERATURE OF SERUM: DEPOLARIZATION FACTOR AND HYDRATION OF SERUM MOLECULES     

Du Noüy PL 《Science (New York, N.Y.)》1930,72(1861):224-225

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安定桥滑坡的稳定性研究     

黄金国 《四川林勘设计》1995,(4):19-25

安定桥滑坡位于四川省木里县博查公路约72公里处。滑坡地层为第四系松散堆积物,松散堆积物中有地下水存在。坡体内有软弱夹层。属于古滑坡体上的部分复活。坡体的滑动是由于古滑坡体内软弱夹层在上部岩体的自重应力及外部因素的综合作用下,产生的蠕动变形。两座拱桥的变形破裂是安定桥滑坡滑动变形所致。对两座拱桥实行加固和修复,有利于坡体的稳定和地方交通安全。  相似文献   

Kinetic study of the physicochemical and microbiological changes in "seasoned" olives during the shelf-life period     

López FN  Romero C  Del Carmen Durán Quintana M  López AL  García PG  Fernández AG 《Journal of agricultural and food chemistry》2005,53(13):5285-5292

The changes that take place during the shelf life of "seasoned" olives (packing conditions: 4% NaCl, 0.1%citric acid, and 0.0175% sorbate) using fresh (FF) and stored (SF) cracked fruits were studied. Texture, L, b, NaCl, and pH experienced slight changes. Values of a and titratable and combined acidity increased following a first-order kinetic with higher constants for FF. Glucose was completely exhausted, and mannitol showed only a slight decline. Hydroxytyrosol and tyrosol contents in brines increased rapidly from the acidic hydrolysis of oleuropein, hydroxytyrosol-4-beta -d-glucoside, and salidroside, the concentrations of which decreased. Sorbate content decreased with time and disappeared completely in SF. Yeasts grew rapidly in FF and were markedly inhibited in SF. There was a moderate growth of lactic acid bacteria in FF, whereas they grew markedly in SF during the first few days. Some of these changes limit the shelf life of the product.  相似文献   

Substituent effects of thiazoline derivatives for fungicidal activities against Magnaporthe grisea     

Jin Kak LeeJin Soo Song  Kee Dal NamHoh-Gyu Hahn  Chang No Yoon 《Pesticide biochemistry and physiology》2011,99(2):125-130

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优质杂种小麦的选育     

刁雁翎  刘树仁  翟玉洁  王岩  徐秋玲 《中国农业大学学报》1993,(Z3):118-119

作物的杂种优势是普遍存在的。利用小麦杂种优势增加小麦产量、改善小麦品质是本世纪农业科学取得的重大成就之一。随着杂种小麦向农业生产和商品市场的不断推进,人们意识到:只有在优质的基础上高产,杂种小麦才有生存竞争力。  相似文献   

湖北林业推进生态文明建设的探索与启示——中共国家林业局党校第42期党员领导干部进修班赴湖北省教学考察调研报告   总被引：1，自引：0，他引：1  

Class No.  Party School of SAT  China 《国家林业局管理干部学院学报》2013,12(3):3-9

林业在湖北省生态文明建设中发挥支撑保障作用。近年来,湖北省各级林业部门以建设生态文明为统领,以兴林富民为宗旨,大力保护并发展林业生态资源,着力推进林业产业发展,积极构建繁荣的生态文化,成效显著。但是,湖北省林业发展在生态文明建设中也面临着挑战。林业要在生态文明建设中做好开拓者、引领者、推进者,要建立符合生态文明发展要求的林业长效机制和林业创新机制。  相似文献