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排序方式: 共有594条查询结果,搜索用时 15 毫秒
1.
Total superoxide dismutase (SOD:superoxide: superoxide oxidoreductase; EC 1.15.1.1) activity and individual activities of its three different metalloenzymes, CuZn-SOD, Fe-SOD, and Mn-SOD, were investigated during senescence of apples (Malus domestica Borkh.). Total SOD activity and relative activities of its three forms varied greatly among cultivars. Activities underwent considerable change during senescence of fruit, but changes were different among cultivars. Whether fruit senesced at 0°C or 20°C had little effect on SOD activities, and application of the antioxidant diphenylamine (DPA) did not alter activities. SOD activities increased with occurrence of the physiological disorder “senescent breakdown,” but did not increase with occurrence of the disorder “superficial scald.” In a given apple cultivar, changes in total SOD activity generally paralleled activities of the different SOD forms. Such activity may reflect changes affecting food and nutritive quality of the fruit. 相似文献
2.
ABSTRACT: Despite ongoing interest in religious group involvement in community development, only limited research has considered whether the mere existence of a place of worship can be linked to neighborhood well‐being. This exploratory study uses a cross‐sectional design to examine the relationships between the presence of churches in high‐poverty neighborhoods and specific measures of neighborhood stability. One‐way analysis of variance (ANOVA) and geographic information system (GIS) software were employed to compare measures of structural permanence, residential tenure, and property valuation from a sample of two types of church (freestanding and storefront) and non‐church areas or “clusters.” The findings provide limited support for the conclusion that storefront churches, while modest and often regarded as less architecturally significant, may be overlooked contributors to the sort of stable urban space where residential population is preserved and investment maintained. 相似文献
3.
WILLIAM E. LEE III 《Journal of food science》1985,50(6):1750-1751
A method is presented which utilizes a personal computer to measure time-intensity (T-I) sensory responses. The judge uses a game paddle which moves an “X” along a fixed scale appearing on the monitor screen to indicate the attribute intensity at each instant in time. A clicker device on the game paddle can be used to record the occurrence of events such as initial mouth entry and time of swallowing. Data acquisition is continuous with the data stored on discs. This technique has advantages over strip chart recorder methods. Disc storage allows rapid and efficient data analysis. Judges can perform the evaluations virtually unsupervised with only minimal training. 相似文献
4.
A new method was investigated for extracting the proteins from green leaves (alfalfa). An opaque white gel formed when an emulsion of chloroplast-free leaf tissue juice and peanut oil was heated for 10 min at 90°C. The proximate composition of this gel was 40% moisture, 2% protein, 57% fat, 0.2% ash, and <1% carbohydrate. SDS-PAGE analysis of the gel suggested that fraction 1 or ribulose bisphosphate carboxylase is the major protein component present. The apparent viscosity of the gel, 5,257 m Pa.sec, was less than one-tenth of mayonnaise. 相似文献
5.
Bicrystals of Al2 O3 were fabricated to study the effects of thermal expansion anisotropy on fracture in a model system containing one grain boundary. Fractures occurred perpendicular to the directions of maximum tensile stress in bicrystals with thermal expansion coefficient differences as low as 0.31×10−60 C−1 and originated at the boundary, probably in areas of high residual stress associated with pores. Numerical stress analysis of two-dimensional model bicrystal configurations showed that stresses induced by thermal expansion anisotropy are maximal in a region localized along the bicrystal boundary. 相似文献
6.
Dielectric measurements and X-ray diffraction studies were made in the system BaTiO3 -BaHfO3 for polycrystalline specimens containing from 0 to 30 mole % BaHfO3 . The maximum in the dielectric constant for each composition in creased as the BaHfO3 concentration was in creased to 16 mole % and then decreased with further BaHfO3 additions. Room-temperature lattice constants and hysteresis loops were meas ured for all compositions. A partial solid-state phase diagram is suggested for the solid solution area of the system. The phase diagram and the dielectric behavior of the system up to 16 mole % BaHfO3 are explained on the basis of Devonshire's thermodynamic theory. The ferroelectric-paraelectric transition in the composition containing 16 mole % BaHfO3 was essentially of second order and occurred between a ferroelectric rhombohedral phase and a paraelectric cubic phase. 相似文献
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8.
GUAR AND LOCUST BEAN GUMS AS PARTIAL REPLACERS OF ALL-PURPOSE FLOUR IN BREAD: AN OBJECTIVE AND SENSORY EVALUATION 总被引:2,自引:0,他引:2
SABINE S. SCHWARZLAFF JANET M. JOHNSON WILLIAM E. BARBEAU SUSAN DUNCAN 《Journal of food quality》1996,19(3):217-229
All purpose flour was partially replaced with locust bean (LBG) and guar gums at 0% (control), 2% and 4% replacement levels in a bread product. All bread treatments were evaluated objectively and subjectively. Two percent LBG replacement significantly increased standing height. Firmness of bread was significantly firmer. Crumb color was not significantly different for any of the 5 bread treatments. Crust color was not significantly different for any of the 5 bread treatments. Crust color, however, was significantly lighter for the control in comparison with the 2% and 4% guar and 4% LBG breads. Two percent guar produced a more even cell size distribution throughout the bread crumb. For all 5 bread formulations moistures were not significantly different. Sensory evaluation revealed a significant difference between the control and 4% LBG. Neither the control nor 4% LBG breads were not significantly preferred. Both gums were found to retard bread staling; 2% LBG was the most effective. 相似文献
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