Functional Properties of Chinese Rapeseed Protein Isolates

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.     

FERMENTATION OF WORTS MADE FROM 100% RAW SORGHUM AND ENZYMES

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.     

DETERMINATION OF SOLUBLE NITROGEN BY SPECTROPHOTOMETRY

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.     

Effects of storage time and chemical preservatives on the total volatile basic nitrogen content in chilean mackerel (Trachurus murphy) prior to fish meal production

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.     

硝酸改性活性碳纤维降低NO性能研究

在微型反应器中对用硝酸处理后的各种活性碳纤维（ACF）进行了脱除NO的实际效果对比,并用硝酸对聚丙烯腈基ACF进行不同时间的处理,确定出处理时间为2－4h较佳。定量考察了不同温度下NO的还原程度及其产物分布,并通过程度升温脱附（TPD）、热重（TG）及扫描电镜？（SEM）的研究,考察了所选ACF在不同气氛下的变化规律,并进行了化学动力学计算。实验结果表明,硝酸处理后的ACF具有较高的脱氮效果。     

硫磺回收装置停工热氮除硫工艺研究

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。     

加氢裂化装置生产工业白油的技术开发与工业应用

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。     

随钻地层流体保真取样筒保真参数优化方法

提出以地面预充氮气方法为主、井下增压方法为辅的随钻取样保真筒的设计思路,对其工作方式、取样参数优化方法进行讨论.取样筒中氮气腔的作用相当于储能气垫,可在一定程度上补充取样过程中因温度变化带来的压力损失,井下增压则是将样品尽快地压入样品腔,并进一步提高样品压力来弥补氮气腔无法提供的压力补偿.通过对取样保真筒工作方式的分析...     

原油加工过程的氮平衡及其传递规律

对国内某炼油厂的常减压蒸馏、加氢裂化、连续重整、柴油加氢、渣油加氢、酮苯脱蜡、糠醛精制、重油催化裂化等21套装置进行全面采样和分析,考察了含氮原油在炼油厂各工艺流程中的分布及传递情况,确定了各装置的氮元素平衡及分布规律,绘制了全厂氮元素传递图,以期为炼油厂深度脱氮、重点装置防腐以及工艺升级等提供技术支撑。     

酸性离子液体催化醛胺缩合反应制备多氮杂环化合物

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%。