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991.
Irradiated restructured pork loins treated with rosemary-tocopherol/double-packaging had lower TBARS values than vacuum-packaged control after 10 days of refrigerated storage. The rosemary-tocopherol combination, however, had no effect on the production of sulfur volatiles responsible for the irradiation off-odor, and color changes in irradiated pork. V7/A3 double-packaging was effective in reducing the sulfur volatiles significantly. Rosemary-tocopherol combination was highly effective in reducing the volatile hexanal in irradiated restructure pork. Irradiation was effective in reducing Listeria monocytogenes and Salmonella typhimurium inoculated on the surface of restructured pork loin in dose-dependent manner. The irradiation D(10) values for L. monocytogenes and S. typhimurium were 0.58 and 0.55kGy, respectively. During the 20 days of refrigerated storage, L. monocytogenes in both nonirradiated and irradiated samples grew gradually, but the number of S. typhimurium decreased. The added rosemary-tocopherol, however, showed little bacteriocidal effects to L. monocytogenes and S. typhimurium. 相似文献
992.
The modern fruit juice industry needs their products to be characterized by high-quality attributes to meet consumers’ expectation. In this view, the composition of 26 Italian commercial apricot juices obtained from organic, integrated and conventional agriculture was analysed for carbohydrates, organic acids, amino acids, phenolic compounds and furanic compounds by high-performance liquid chromatography (HPLC). The content of 5-hydroxymethylfurfural in apricot juices (range 0.1–18 mg/l) was within the regulatory limit of 20 mg/l. The lack of furanic compounds in apricot fresh fruits confirmed their importance as quality markers of heating condition during processing and storage of fruit juices. Univariate analysis disclosed some significant differences among the composition of the apricot juices in terms of glucose, fructose, malic acid, glycine, chlorogenic acid, rutin, and a∗-parameter (redness). Principal component analysis on chemical composition of apricot juices resulted in two principal components (PCs) that accounted for 66% of the total variance. Organic apricot juices showed some separation from the other juices, whereas a lack of distinction between integrated and conventional juices appeared. 相似文献
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U.M. Cowgill 《The Science of the total environment》1973,2(3):259-303
A hydrogeochemical study to determine the abundance of the chemical elements in the water of Linsley Pond, North Branford, Conn., U.S.A., was initiated in 1965. As the investigation progressed, it became clear that the aquatic macrophytes, associated sediments, and the soils and rocks of the basin had to be examined chemically in order to elucidate the biogeochemical cycle of the elements in the water. This aspect of the study concerns the elemental chemical composition of Nymphaea odorata Ait. and the aphid Rhopalosiphum nymphaeae (L.) feeding on its leaves. Thirty-five elements were detected in the water but fifty-four were found in this water-lily and its aphid. Those not encountered in lake water concentrated twenty-fold were Cs, Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb, Ge, Zr, Hf, Th, As, Nb and Se. The water-lily, the aphid, the lake sediment and the soils and rocks of the basin all contained detectable quantities of the rare earths, though beyond Sm only those of even atomic number were encountered. The aphids contained more Na, Li, Cs, Ba, Zn, Al, Ga, Si, Ge, Pb, Ti, Hf, P, Bi, S, Se, Cr, Mo, I, Fe, Co, Ni, Mn, Y, La, Ce, Pr and Sm than the leaves upon which they feed. The water-lily leaves contain more Ag, Ca, Mg, Cd, Hg, B, Sn, Zr, Th, Cl, Br, Nd and Sc than the aphids. The amount of Be, Gd, Dy, Er, Yb, K, Rb, Cu, Sr, As, V and F is essentially the same in the insects as in the leaves which support them. Pertinent comparative data from other sources are also presented. 相似文献
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提出了一种用于三相接地系统的基于半控桥的新型短路故障限流器拓扑结构。对新型限流器在单相对地短路、两相对地短路和三相短路状态下的控制方法和限流工作原理进行了详细介绍。该限流器中含有一对功率二极管组成的桥路,可以自动为直流电感提供续流通道,因此,在短路故障发生并被检测到之后,只需要控制关断与故障相相连接的桥臂上的开关管,则故障相即可退出系统,非故障相仍然正常供电。采用PSIM6软件,对各种短路模式下的限流方法及限流效果进行仿真研究。制作了小容量的半控桥式限流器实验装置,并进行了详细的实验研究,给出了3种短路模式下主要变量的实验波形。仿真和实验结果一致,验证了所提限流器及其控制策略的有效性和实用性。 相似文献
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Recent developments in the design of bifunctional and activatable photosensitizers rejuvenate the aging field of photodynamic sensitization and photodynamic therapy. While systematic studies have uncovered new dyes that can serve as potential photosensitizers, the most promising results have come from studies aimed at gaining precise control over the location and rate of cytotoxic singlet oxygen generation. As a consequence, higher selectivities and efficiencies in photodynamic treatment protocols are now within reach. This feature article highlights the variety of approaches that have been pursued to improve photodynamic therapy and to transform simple photosensitizers into smarter theranostic agents. 相似文献