用富集培养技术分离具有PAL活性的酵母菌

为获取具有ＰＡＬ活性的菌株，设计了从天然源分离酵母菌的定集培养技术，并从中国西南地区采集２０个样品中得到菌株１４０余株，结果表明本富集培养技术用于从天然源分离具有苯丙氨酸解氨酶活性的菌株是有效、可行的。     

Flame jet properties of Bunsen-type flames

The flame jet width and flame jet velocity of the burnt gases of a premixed Bunsen-type flame are important parameters for quantifying the heat-transfer rates of these flames. In this paper a simple expression is derived to estimate the flame jet width and flame jet velocity of burnt gases of a free flame after expansion over the flame front for the special case of plug flow in and above the burner. The results of particle image velocimetry experiments on three different flame types having different oxygen concentrations are presented. The model is validated with these measurements and shows good agreement. Deviations occur, however, when the curved flame front area of the flame tip is not negligible compared to the total flame area.     

生物样品富集微芯片

微全分析系统(micrototalanalyticalsystem,μTAS)是一个快速发展的领域,生物样品的富集和提取是样品分析的重要环节。由于生物样品种类多、成分复杂,在微芯片上富集和分离较为困难,是微全分析系统发展需要突破的瓶颈之一。介绍了不同类型的生物样品微富集芯片工作的原理、近来的研究进展情况以及存在的问题。     

斜筛替代单圆网浓缩机用于废纸浆料浓缩工艺改进

着重介绍了斜筛替代单圆网浓缩机用于废纸制浆浓缩工序的应用实践,及浓缩工序改进后取得的效果;应用实践表明:浓缩工序改进后用于废纸制浆的外排白水中的浆料流失由1.18g/L降低到0.78g/L,流失率降低了38.9%,吨浆电耗下降了30%,供浆浓度得以稳定控制在(4.0±0.2)%。     

Prebiotic fibre‐incorporated whey protein crisps processed by supercritical fluid extrusion

Prebiotic soluble fibre (fructooligosaccharides)‐incorporated whey protein crisps were produced by low‐shear supercritical fluid extrusion (SCFX), which utilises supercritical CO₂ as an expansion agent instead of steam. Protein crisps with desirable qualities were obtained with a formulation containing 8% prebiotic fibre and 60% whey protein concentrate (WPC‐80), which gave the final product with a protein content of 49.6% (w/w). A maximum of 70% WPC‐80 and 8% prebiotic fibre could be incorporated to produce expanded protein crisps; however, increasing WPC‐80 from 50% to 70% decreased the end‐product expansion ratio from 3.1 to 1.2 and increased the product hardness and piece density from 1.3 to 2.8 kN and 0.63 to 0.75 g mL^?1, respectively. Addition of 8% prebiotic fibre did not affect the textural qualities of final products. The process produced an expanded protein matrix with unique internal microstructure of uniformly distributed closed cells. Amino acid analysis indicated that 90% of the total lysine and 92% of the total essential amino acids were retained after SCFX processing and oven‐drying, indicating the preservation of protein nutritional quality during the process.     

酶法纯化ω-6和ω-3多不饱和脂肪酸研究进展

多不饱和脂肪酸(PUFAs)具有重要的生理学活性,尤其是ω-6和ω-3系列与人体健康密切相关。因此,如何提取PUFAs非常重要,也是油脂领域的研究热点。利用酶法分离纯化PUFAs是一种环保、高效、具有广泛应用前景的方法。本文综述了酶法纯化ω-6和ω-3PUFAs的最新研究进展,并着重阐述了酶法催化水解、酶法选择性富集以及其它几种能和酶法有效结合、共同分离纯化PUFAs的物理化学方法,同时通过论述亚油酸、亚麻酸、花生四烯酸等PUFAs的纯化进展证明了酶法在该领域内具有很大发展前景。     

乳酸菌富硒及产胞外多糖条件的研究

试验以实验室保藏的6株乳酸菌为研究对象,筛选出最佳试验条件下富硒率和产胞外多糖含量最优的菌株,以期为生产富硒调味品提供一定的理论依据.通过测定其生长曲线确定各菌的加硒时间,对比6株乳酸菌在不同亚硒酸钠质量浓度下的颜色变化、富硒率变化和胞外多糖含量变化,选定鼠李糖乳杆菌作为最佳试验菌株;通过测定鼠李糖乳杆菌在不同培养时间...     

浓香型白酒絮状悬浮物富集分离方法的探讨

通过对浓香型白酒絮状悬浮物物理性质系统分析,得出有效的富集分离方法。在20~25℃环境下,静止25~35 d絮状悬浮物量多,且稳定,利用加长针管最大限度吸取酒液,得到量多且稳定的絮状悬浮物,便于分析主成分,为预防白酒出现絮状悬浮物提供技术支撑。     

高浓度糖蜜发酵酒精废液浓缩焚烧技术

本文重点介绍以高温烟气增浓器和全废液喷燃炉组成的酒精废液浓缩焚烧系统的运行效果.结果表明,该技术解决了废液浓缩燃烧产生积垢结焦的难题,达到浓缩和焚烧热能自给平衡,投资小、占地少、流程短、操作简单、运行费用低、彻底解决废液造成的污染,开创了糖蜜酒精废液处理的新方法.     

极大螺旋藻培养及生物富硒条件的优化

为获得高富硒量的极大螺旋藻,在硒添加方式为8d等量多次添加800μg/mL Se(Ⅳ)的前提下,通过单因子试验研究了初始pH值、光照强度、NaHCO3浓度和NaNO3浓度对富硒极大螺旋藻生物量和硒富集效果的影响.在光照20001x∶50001x= 12h∶ 12h条件下,通过L9 (34)正交试验确定了NaHCO3浓度12.8g/L、NaNO3浓度2.5g/L、pH值9.8为极大螺旋藻生物富硒的最佳条件,得到了生物量为2.517g/L,总硒含量为2.843mg/g(干重)的富硒极大螺旋藻.