Characterization of haze-active proteins in apple juice   总被引：8，自引：0，他引：8  

Wu LC  Siebert KJ 《Journal of agricultural and food chemistry》2002,50(13):3828-3834

The nature of the haze-active protein (HAP) in apple juice was investigated. Heat treatment removed protein indiscriminately while polyvinylpolypyrrolidone (PVPP) treatment was fairly specific for proteins of 15 and 28 kDa. Presumably, the PVPP bound to polyphenols, which in turn were complexed with protein. Three candidate apple HAPs were isolated. Two were extracted from juice with acetone and fractionated by hydrophobic interaction chromatography and solid phase extraction with C18 (HAP I) or SAX (HAP II) material. Hydroxyproline-rich protein was extracted from apple tissue (HAP III). The order of haze formation with tannic acid was gliadin > HAP III > HAP II > HAP I > bovine serum albumin, which shows increasing haze formation with increasing proline content. The sizes of HAP I, II, and III were 28, 15, and 12 kDa; the first two corresponded to the sizes of proteins removed by PVPP treatment and are involved in juice haze formation.  相似文献   

Gross nitrogen transformations in adjacent native and plantation forests of subtropical Australia     

Joanne Burton  Chengrong Chen  Hossein Ghadiri 《Soil biology & biochemistry》2007,39(2):426-433

The impact of land-use change on soil nitrogen (N) transformations was investigated in adjacent native forest (NF), 53 y-old first rotation (1R) and 5 y-old second rotation (2R) hoop pine (Araucaia cunninghamii) plantations. The ¹⁵N isotope dilution method was used to quantify gross rates of N transformations in aerobic and anaerobic laboratory incubations. Results showed that the land-use change had a significant impact on the soil N transformations. Gross ammonification rates in the aerobic incubation ranged between 0.62 and 1.78 mg N kg⁻¹ d⁻¹, while gross nitrification rates ranged between 2.1 and 6.6 mg N kg⁻¹ d⁻¹. Gross ammonification rates were significantly lower in the NF and the 1R soils than in the 2R soils, however gross nitrification rates were significantly higher in the NF soils than in the plantation soils. The greater rates of gross nitrification found in the NF soil compared to the plantation soils, were related to lower soil C:N ratios (i.e. more labile soil N under NF). Nitrification was found to be the dominant soil N transformation process in the contrasting forest ecosystems. This might be attributed to certain site conditions which may favour the nitrifying community, such as the dry climate and tree species. There was some evidence to suggest that heterotrophic nitrifiers may undertake a significant portion of nitrification.  相似文献   

The migration of fallout 134Cs, 137Cs and 106Ru from Chernobyl and of 137Cs from weapons testing in a forest soil     

Kurt Bunzl  Wolfgang Schimmack  Karl Kreutzer  Rudolf Schierl 《植物养料与土壤学杂志》1989,152(1):39-44

To estimate the accumulation and vertical migration of radiocesium and radioruthenium, the activity concentrations of Chernobyl-derived ¹³⁴Cs, ¹³⁷Cs and ¹⁰⁶Ru as well as of ¹³⁷Cs from the global fallout of weapons testing observed in the upper horizons of a forest soil (Hapludult, spruce stand) were evaluated with a compartment model. The resulting residence half-times were used to estimate the mean rates of transport of these radionuclides. For Chernobyl-derived ¹³⁴Cs and ¹³⁷Cs within the time period of 200–600 days after the beginning of the fallout the rates were between 4 cm/yr (Of1-horizon) and 2 cm/yr (Oh-horizon), and for ¹⁰⁶Ru between 4 cm/yr (Of1-horizon) and 7 cm/yr (Oh-horizon). These rates, though considerably slower than observed in the same soil during the initial infiltration of these radionuclides with a rain shower, are (depending on the soil horizon) still higher by a factor of 3–6, when compared to the rates of transport of ¹³⁷Cs from the global fallout of weapons testing in the same soil. Because global fallout ¹³⁷Cs is in the soil since about 20 years, these results suggest that the fixation of radiocesium in the forest soil is a rather slow process.  相似文献   

The toxicity of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to the freshwater green alga Selenastrum capricornutum     

Dennis T. Burton  Steven D. Turley  Gregory T. Peters 《Water, air, and soil pollution》1994,76(3-4):449-457

RDX was not acutely toxic to the green alga Selenastrum capricornutum when tested at the solubility limit of the compound in algal assay media. A maximum reduction of 38% in cell density occurred after a 96-h exposure to 36.7 mg L^?1; thus, an EC50 could not be determined. The lowest-observed-effect concentration (LOEC) and no-observed-effect concentration (NOEC) for the green alga were 4.8 and 0.5 mg L^?1 (reduction in cell density), respectively, when chronic end points were used to analyze the data. A comparison of the data in this study with RDX toxicity data from the literature for the diatom Navicula pelliculosa, and the blue-green algae (cyanobacteria) Microcystis aeruginosa and Anabeana flos-aquae shows that S. capricornutum is the most sensitive to RDX. A U.S. Environmental Protection Agency (EPA) numerical water quality criterion Final Plant Value based on the green alga data should protect the above algal groups.  相似文献   

Further information on farro (Triticum monococcum L. andT. dicoccon Schrank) in South Italy     

Karl Hammer  Pietro Perrino 《Genetic Resources and Crop Evolution》1984,32(2):143-151

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Total 14C residues and dieldrin residues in milk and tissues of cows fed dieldrin-14C     

J C Potter  R L Marxmiller  G F Barber  R Young  J E Loeffler  W B Burton  L D Dixon 《Journal of agricultural and food chemistry》1974,22(5):889-899

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Collection of plant genetic resources in South Italy, 1988     

Karl Hammer  Gaetano Laghetti  Pietro Perrino 《Genetic Resources and Crop Evolution》1989,37(2):401-414

Summary Exploration and collection of plant genetic resources were continued in South Italy in 1988. Parts of the regions Campania, Basilicata and Apulia were covered in September jointly by staff members of the Istituto del Germoplasma, Bari, and the Zentralinstitut für Genetik und Kulturpflanzenforschung, Gatersleben. 164 samples, mainly of vegetables and grain legumes, have been collected. Worth mentioning are land-races of tomatoes,Brassica spp. andVigna unguiculata. As a part of the collecting area has been explored for the second time after eight years, the effects of genetic erosion could be observed. A map summarizes the itineraries of the ten joint collecting missions in South Italy.

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Sammlung pflanzlicher genetischer Ressourcen in Süditalien 1988

Zusammenfassung Die Exploration und Sammlung pflanzlicher genetischer Ressourcen wurden 1988 in Süditalien fortgesetzt. Im September wurden Teile der Regionen Campania, Basilicata und Apulia gemeinsam von Mitarbeitern des Istituto del Germoplasma, Bari, und des Zentralinstituts für Genetik und Kulturpflanzenforschung, Gatersleben, erfaßt. 164 Proben, besonders von Gemüsen und Körnerleguminosen, wurden gesammelt. Erwähnenswert sind Landsorten von Tomaten, Kohlarten undVigna unguiculata. Da ein Teil des Sammelgebietes im Abstand von acht Jahren ein zweites Mal in die Exploration einbezogen wurde, konnte das Wirken der Generosion verfolgt werden.Die Reiserouten der zehn gemeinsamen Sammelreisen in Süditalien werden zusammenfassend in einer Karte dargestellt.

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1988

1988. . . () (). 164 . . , Vigna unguiculata. 8 . .

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Stickstoffstatus eines Braunerde-Podsols unter Kiefer zehn Jahre nach Melioration mit Müllkompost     

Claus-Eberhard Grüneklee  Wolfgang Moll  Karl Günter Kern 《植物养料与土壤学杂志》1993,156(1):39-44

Nitrogen status of a Scots pine site 10 years after fertilization with composted municipal waste A haplorthod was fertilized with composted municipal waste (CMW) in 1978. The N-losses in a 10 year observation time are in the range of conventional fertilizer experiments. The C/N-ratio of the organic layers was narrowed after treatment. The fractional determination of the organic forms of nitrogen showed an increase of the stable humin-N-fractions in the organic layers of the treated plots. In comparison with the untreated plots, the amount of mineralizable nitrogen in the organic layers decreased, the NH₄/NO₃-ratio was narrowed. The N-content of the pine-needles increased. The better N-supply of the pines (Pinus silvestris) caused an increase of the basal area increment.  相似文献   

Comparison of avoidance responses of an estuarine fish,Fundulus heteroclitus,and crustacean,Palaemonetes pugio,to bis (tri-n-butyltin) oxide     

Alfred E. Pinkney  Lenwood W. Hall Jr.  Michael J. Lenkevich  Dennis T. Burton  Scott Zeger 《Water, air, and soil pollution》1985,25(1):33-40

Avoidance responses of an estuarine fish, mummichog (Fundulus heteroclitus), and crustacean, grass shrimp (Palaemonetes pugio) to the antifoulant his (tri-n-butyltin) oxide (TBTO) were evaluated. Four out of six groups of mummichogs tested at 1.0 μg total organic Sn L^?1 showed avoidance. Total organic Sn concentrations of ≥ 3.7 μg L^?1 were avoided by this fish species in all cases. Higher concentrations of total organic Sn did not result in greater avoidance responses. Grass shrimp did not avoid total organic Sn concentrations between 2.3 and 30.0 μg L^?1. Response data at 2.3 and 30 μg L^?1 were similar. Mummichogs and grass shrimp differed greatly in their abilities to avoid potentially adverse concentrations of total organic Sn. Since mummichogs are major predators of grass shrimp, these behavioral responses may have important implications for tidal marsh ecosystems.  相似文献   

Chemical assessment of roots of Panax notoginseng in China: regional and seasonal variations in its active constituents   总被引：19，自引：0，他引：19  

Dong TT  Cui XM  Song ZH  Zhao KJ  Ji ZN  Lo CK  Tsim KW 《Journal of agricultural and food chemistry》2003,51(16):4617-4623

Root of Panax notoginseng (Radix Notoginseng, Sanqi) is a well-known traditional Chinese medicine and is mainly cultivated in Wenshan of Yunnan, China. The active constituents include saponin, dencichine, flavonoid, and polysaccharide; however, the levels of these components vary in different geographical regions of growth and also show a seasonal variation. By using high-performance liquid chromatography and spectrophotometry, the contents of notoginsenoside R1, ginsenoside R(g1), R(b1), R(d), dencichine, flavonoid, and polysaccharide were determined and compared with Radix Notoginseng collected from different regions of growth in China, as well as from different seasons of harvest and market grades. Using the contents of these active constituents as markers, the best quality of Radix Notoginseng is found in the southwestern parts of Wenshan, and the best season for the harvest is September to October. In addition, the unseeded plants produced a better quality of Radix Notoginseng. The current results provide useful information for the quality control of Radix Notoginseng and its further development in establishing the good agriculture practice standard of P. notoginseng in China.  相似文献