外加酶制备麦汁的研究

以燕麦为辅料制备麦芽汁,采用正交试验设计,探讨它们对麦芽汁品质的影响。方差分析结果表明:NSP酶的添加量对麦汁的过滤时间、糖化时间、α-氨基氮量、还原糖量和收得率均有显著性影响(p<0.05),NSP酶的添加阶段和燕麦添加量均只对麦汁中α-氨基氮量有显著性影响(p<0.05),而NSP酶的作用时间对测定的理化指标均无显著性影响(p>0.05)。因此,在本试验条件下,确定的最佳工艺条件为:NSP复合酶添加量0.24%,燕麦添加量为30%,NSP复合酶在蛋白质休止阶段(45℃~50℃)添加、保温23min。     

水泥厂热风管道的优化设计(一)

以2500t/d新型干法窑生产线为例,进行了热风管道的优化设计的三方面研究:(1)介绍了窑尾风管的四种优化方案,每种方案均可有效缩短管道高度5m左右,从而可降低建设钢材用量约10t左右,且能减小运行阻力、节约电耗。(2)进行了用钢板焊成的风管弯头的柔性研究,计算了弯头的柔性系数和应力增大系数。结果表明,完成与直管相同的变形,钢板焊成的风管弯头所产生的力远远小于直管;但弯头处应力则远大于直管。(3)对一级筒至增湿塔风管及窑尾烟囱在预热器塔架上的导向支座方案进行了研究探讨。研究表明,悬挑梁支承方案用钢量较高;而用简单的拉压杆支承体系,在保证热风管道和烟囱在风载荷或地震作用下水平方向稳定时,可实现纵向自由伸缩,并可有效节约建设投资。     

Structure of pectin in relation to abnormal hardness after cooking in pre-peeled, cool-stored potatoes

Unacceptable hard tissue can be detected in pre-peeled potatoes after cooking. Pectin methyl esterase (PME) has been suspected to facilitate formation of Ca-bridges between pectin molecules by deesterification of the uronic acids. But this has also been questioned, due to the low storage temperature of the peeled tubers, optimum of PME being 50-70 °C. Hardness in tubers was induced by several packaging methods. Annual and seasonal variations were observed. In the work, analysis of nonstarch polysaccharides (NSP) are considered representative of the pectin content. Analyses revealed an increase in insoluble NSP during storage after peeling and cooking, and a decrease in branching (arabinose, galactose) and degree of methyl esterification of total NSP, in both fresh and cooked tissue, dependant on storage period. Reduction of steric hindrance by debranching of the pectin molecules as well as a PME-induced increase of possible Ca-cross-linking sites may favor hardening of the tissue. The microscopy does not show any pectin changes until after cooking, but the chemical data do. This suggests that hardening, at least partly, is due to the removal of methyl ester groups, as well as galactose and arabinose in the side chains. The Ca-bridges can probably not be formed until sufficient calcium is released from the starch during gelatination.     

人轮状病毒VP7、NSP4基因的适应性进化分析

轮状病毒足引起人类和动物急性腹泻的传染病毒,其外壳蛋白VFr7决定血清型G型并在诱导产生中和抗体中具有重要的作用,NSP4蛋白作为轮状病毒致泻蛋白,在疫苗研究中亦备受瞩目.本文应用最大似然法分析中国区G1～G3型VP7、NSP4蛋白编码序列.其中VP7序列未发现正选择位点,NSP4中共发现3个正选择位点,这些经历正选择作用的位点位于不同的序列功能区内,暗示这些位点可能对相关的功能贡献决定性作用.本研究的结果为轮状病毒的免疫研究提供参考.     

余热发电项目热工检测分析

对琉璃河水泥厂2500t/d新型干法水泥生产线余热发电前后进行了两次热工检测,从实际测定和理论上客观地分析了余热发电建设对水泥生产的影响,为新型干法水泥生产线如何在保证熟料烧成系统稳定运行的情况下,充分利用烧成系统产生的废气余热来进行余热发电提供了很好的参考依据。     

Towards a better understanding of the pectin structure–function relationship in broccoli during processing: Part II — Analyses with anti-pectin antibodies

To investigate the structure–function relationship of pectin during (pre)processing, broccoli samples (Brassica oleracea L. cultivar italica) were subjected to one of the following pretreatments: (i) low-temperature blanching (LTB), (ii) LTB in combination with Ca²⁺ infusion, (iii) high-pressure pretreatment (HP), (iv) HP in combination with Ca²⁺ infusion, or (v) no pretreatment (control sample), whether or not in combination with a thermal treatment of 15 min at 90 °C. Anti-homogalacturonan antibodies were used to perform in situ (microscopy) and ex situ (immuno-dot assays) analyses on broccoli pectin which resulted in information concerning the localisation of defined pectic domains in broccoli cell walls and pectin's structure. Water-soluble pectin appears to contain unbranched, high-esterified pectin and some pectic polymers with abundant side chains that are less esterified. Ionically cross-linked pectin, on the other hand, contains low-esterified pectin with either highly branched or unbranched domains. The in situ visualisation of pectin in broccoli suggested that de-esterification of pectin by PME during LTB as well as during HP mainly takes place in the tricellular junctions of adjacent cells in broccoli tissue. Ca²⁺-cross-linked pectin could be found in cell walls lining intercellular spaces and was particularly abundant at the corners of intercellular spaces, indicating its important role in cell–cell adhesion. Both LTB and HP created pectin–Ca²⁺-cross-links in parts of the cell wall where these cross-links were originally absent. The influence of thermal processing and the effect of pressurisation on the pectic components in the cell wall could also be visualised using the antibodies.     

NSP酶对大麦体外消化的影响

大麦体外消化试验结果揭示，添加NSP酶（GXC）使大麦中干物质、粗蛋白、粗灰分、无氮浸出物、粗脂肪和粗纤维的消化率分别提高了18．13％、20．27％、15．99％、16．42％、和26．93％和30．02％；大麦中各种氨基酸体外消化率显著提高，幅度为11．83％－61．39％；添加NSP酶使大麦胚乳细胞壁在体外完全降解；消化过滤液中葡萄糖和总氨基酸含量分别提高了17．58％和10．26％；而粘度降低了4．51％。     

对里氏木霉Rut C-30所产非淀粉多糖酶系的分析

通过里氏木霉RutC 3 0以稻草和麸皮为基质进行固态发酵 ,对其产生的非淀粉多糖酶(NSP酶 )进行分析 ,试验表明里氏木霉RutC 3 0产生的NSP酶系较全 ,分别有纤维素酶、木聚糖酶、β 葡聚糖酶、β 甘露聚糖酶、果胶酶等 5种不同的NSP酶。并探讨了不同碳源及添加不同底物诱导物对里氏木霉RutC 3 0产生的NSP酶系的影响     

莜麦面可溶性膳食纤维的研究

莜麦面是糖尿病疗效食品。为了探明莜麦面中降糖降脂的有效成份，对莜麦面中可溶性膳食纤维作了探索。以莜麦面中可溶性非淀粉多糖（ＮＳＰ）作为可溶性膳食纤维的指标，研究了ＮＳＰ的提取、分离纯化和含量测定的方法，测定了莜麦面和富强面中ＮＳＰ含量，并对２种面粉所含的不溶性膳食纤维、蛋白质、脂肪和淀粉作了对比。其结果是：莜麦面中ＮＳＰ的含量是富强面的９．０倍，不溶性膳食纤维为８．６３倍、蛋白质为１．４０倍、脂肪为８．５６倍，而淀粉仅为０．８４倍。结果表明ＮＳＰ可能是莜麦面降糖降脂的有效成份，且莜麦面中不溶性膳食纤维和淀粉的含量也利于血糖的降低。ＮＳＰ分离纯化的成功为探索莜麦面食疗功效有效成份开辟了一条新的途径。     

2500t/d新型干法窑高质高产原因分析

中材国际南京水泥工业设计研究院承担设计的2500t／d新型干法水泥生产线已有数十条投产，并且所有的生产线实际产量都超过了设计能力产量。以其中两条线的实践经验为基础，通过分析生产中出现的问题和介绍其解决措施．总结出一些共同的高质高产的原因，如管理水平、窑系统的合理设计、燃烧器的选择、操作水平等。