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61.
Functional Properties of Chinese Rapeseed Protein Isolates 总被引:4,自引:0,他引:4
A membrane-based protein isolation process developed in our laboratory produced two protein isolates from CH3OH/NH3/H2O-hexane-extracted Chinese rapeseed meal. Both contained ~99% protein (NX6.25), and they were essentially free of glucosinolates or their breakdown products (<2,2 μmol/g). Their functional properties were evaluated and compared with a commercial soybean protein isolate. The precipitated isolate gave high values for all properties except nitrogen solubility index (NSI) while the soluble isolate showed excellent NSI and fat absorption but poor emulsification characteristics. They both had good foaming properties. The two Chinese rapeseed protein isolates complemented each other and were comparable to soybean protein isolate in most functions. 相似文献
62.
Worts made from raw sorghum and enzymes were successfully fermented even though the level of FAN present (51 mg/l) is well below that essential for fermentation of wort made from malted barley. Changes in typical fermentation parameters such as specific gravity, pH uptake of free amino nitrogen (FAN) and ammonium ions mirrored the increase in yeast cell concentration. Yeast viability remained high throughout the fermentation. Under identical fermentation conditions, malted barley worts showed typical fermentation profiles. However, malted barley worts with specific gravity maintained by the addition of D-glucose, but in which the FAN was diluted to a level similar to that found in a wort made from sorghum and enzymes, fermented more slowly and failed to attenuate fully. Five consecutive fermentations, using yeast cropped from the preceding to pitch the current fermentation were conducted. The specific gravity profiles were essentially the same in all five fermentations. Final values of pH, yeast in suspension, yeast viability and FAN were also indistinguishable. The yeast crop taken from fermentations of worts made from raw sorghum and enzymes represented a 5-fold increase over the initial pitching rate. When compared to commercial beers, the beers derived from fermentation of worts made from raw sorghum and enzymes contained lower levels of ethyl acetate, and higher levels of both 2- and 3-methyl butanol. In the beers derived from sorghum, isobutanol was always less than 20% of the total higher alcohol concentration. 相似文献
63.
A simple spectrophotometric method for the determination of nitrogen in unhopped wort has been tested by the EBC Analysis Committee and accepted for inclusion in Analytica-EBC. The spectrophotometric method is intended as a quick method for routine quality control. It is emphasized that the procedure has to be followed in detail and that the precautions stated under Notes on Procedure are most important. The average precision values obtained for the range 600 to 850 mg/litre were r95=30 and R95 = 104. 相似文献
64.
Rodrigo Brquez Mario Espinoza Rodrigo Ormeo 《Journal of the science of food and agriculture》1994,66(2):181-186
Total volatile basic nitrogen (TVB-N) as a measure of protein degradation and total microbial counts or stored raw mackerel (Trachurus murphy), which had been treated with chemical preservatives, were compared with the TVB-N and microbial counts of untreated fish. In unpreserved fish, decomposition of fish protein was rapid. Treatment of mackerel with acetic (1000-5000 μg kg?1), which was the most effective of the parameters studied, approximately halved the rate of increase in TVB-N compared with the untreated samples. Changes in the total microbial counts presented a similar trend. 相似文献
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66.
目的 降低硫磺回收装置停工除硫期间尾气中SO2排放量。方法 对比传统燃料气除硫及热氮除硫工艺的技术特点、原理及优缺点,采用Aspen Plus软件进行模拟计算,并结合热氮除硫工艺的技术特点,对3个阶段的除硫流程进行优化操作。结果 通过对比分析及Aspen Plus软件模拟计算结果可知,热氮除硫技术可降低硫磺回收装置停工期间的SO2排放量,将排放尾气中SO2质量浓度控制在400 mg/m3以下。结论 采用热氮除硫工艺可解决硫磺回收装置停工除硫期间尾气SO2排放量大的问题,但也存在N2消耗量大、停工除硫时间长等问题。今后,在优化N2消耗量、缩短停工除硫时间的基础上,热氮除硫技术将会得到推广应用。 相似文献
67.
目的 降低炼厂的柴汽比,提高企业经济效益。方法 对惠州石化4.0 Mt/a蜡油加氢裂化装置生产5号工业白油的可行性进行了分析,认为通过提高柴油馏分初馏点实现生产5号工业白油产品是可行的。前期,装置已通过主分馏塔降压调整、增设蒸汽汽提塔和原柴油汽提塔再沸器改蒸汽汽提工艺3种方式提高柴油初馏点,均未取得良好的运行效果。鉴于以上3种工艺的局限性,开发了热氮气气提工艺,工艺采用热氮气气提替代柴油汽提塔塔底再沸器,主分馏塔塔顶排出不凝气,以维持塔压稳定。结果 该工艺实施后,装置生产合格白油60 t/h,航煤产量增加14 t/h,不凝气产量增加1.3 t/h,不再产柴油产品;白油产品开口闪点由85℃提高至126℃,解决了开口闪点低和产品含水问题。结论 采用该工艺生产的5号工业白油产品性质稳定,满足行业指标的要求,装置改造工程量小,经济效益显著,对国内外同类装置的生产优化具有重要的借鉴意义。 相似文献
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70.
设计合成了一种新型酸性离子液体1-十二烷基-3-丙磺酸基咪唑硫酸氢盐[C_3SO_3H Doim]HSO_4,将其用于醛胺缩合反应中,制备含能材料中间体。以四氢-咪唑并[4,5-d]咪唑-2,5-二酮,2,5,7,9-四氮杂双环[4.3.0]壬酮-8和六苄基六氮杂异伍兹烷(HBIW)的合成为例,研究了离子液体的种类、用量以及反应温度、反应时间等因素对缩合反应的影响。结果表明,新型酸性离子液体[C_3SO_3H D oim]HSO_4催化活性好,可循环利用率高,三种多氮杂环化合物:甘脲、2,5,7,9-四氮杂双环[4.3.0]壬酮-8和HBIW的收率分别高达95%,89%,81%。 相似文献