Dispersion—flocculation studies on a Goethite-clay system

Dispersion–flocculation studies on a Goethite–clay system using flocculants were carried out as a function of flocculant concentrations, pH of slurry, time of agitation and dispersant dosage. Also, the effects of pH and polymer concentrations on the adsorption behaviour of the system were investigated. Results show that well flocculated goethite was preferentially obtained from 4% goethite/kaolinite clay suspensions, with 50 ppm causticised starch in the slurry at pH values of 3–11·5 and with 50 ppm polyacrylamide at pH values of 3–8. Good flocs were also obtained on flocculation of the goethite suspension with 50 ppm polyacrylamide at pH values of 5–7, while the kaolinite suspension did not respond to the same dosage of causticised starch in the same pH range. Results further reveal that for the goethite/kaolinite suspension, the best results was obtained with 50 ppm polyacrylamide at pH values of 7–10. Based on the data generated in the study, it was concluded that causticised starch is a better flocculant than polyacrylamide for goethite suspensions although polyacrylamide is an excellent flocculant for kaolinite suspensions.     

木薯发酵制备酒精后剩余残渣的综合利用

木薯发酵制备乙醇会产生大量以淀粉和纤维素为主要成分的残渣。经实验证明,在浓硫酸(60%)、浓硝酸和催化剂共同作用下,经水解-氧化-水解可成功地将木薯渣制备成草酸。实验确定了用木薯渣制备草酸的较优条件,测定了产品的熔点,分析了剩余残渣、废水,结果表明剩余残渣和废水不会对环境造成污染,既为草酸的生产提供了新思路,又为农产品的残渣综合利用找到途径,发展前景广阔。     

氧化芋头淀粉理化性质研究

以芋头淀粉为原料、过氧化氢为氧化剂,在碱性介质中制备了低氧化度芋头淀粉。经扫描电镜分析,氧化芋头淀粉颗粒呈多角状,平均颗粒直径18.09μm。X-射线衍射确定其晶体形貌为A型结构。流变学分析其糊化温度为79.5℃、特性粘度为2.505 Pa.s,粘弹性曲线显示其粘性大于弹性。其塑性测定结果符合Croass模型,稠度指数为85.56 s。     

阳离子淀粉的合成

本文阐述了CS—3淀粉的反应机理,并结合工业生产指出阳离子淀粉的合成中重要的技术问题;另外还利用重复取样的方差分析方法确定了CS—3淀粉的工艺操作条件及主要影响因素。     

太湖流域不同种浮萍淀粉积累的研究

对在太湖采集的15株浮萍进行分子鉴定,从中筛选出3株高淀粉含量浮萍作为供试材料,对其生长培养基进行优化,并研究饥饿条件对其生长和淀粉积累的影响。结果表明:采集到的浮萍分布于5个种,分别为Lemna aequinoctialis,Lemna minor,Lemna turionfera,Spirodela polyrhiza,Landoltia punctata;与SH培养基相比,改良的培养基SH-1和SH-2均能显著促进浮萍的生长;在饥饿试验中,筛选的3种浮萍S.polyrhizza,L.aequinoctialis和L.punctata每周的生长速率(以鲜重计)分别为18.64,20.77和16.52g/m2,饥饿培养33 d后,淀粉含量分别达到20.6%,21.98%和24.30%,较饥饿前分别增加了73.4%,75.4%和137.5%。相较于S.polyrhiza和L.aequinoctialis,L.punctata在淀粉积累方面表现出一定的优势。     

The effect of field drying on the non-structural carbohydrate composition in vetch hay

Common vetch (Vicia sativa L) was harvested and allowed to dry in the open air. The composition of fresh forage in non-structural carbohydrates varied markedly between years, the contents of sugars and starch in both leaves and stems being much higher in 1990-91 than 1991-92. Field drying produced a significant decrease in the amounts of these carbohydrates. The total losses of sugars and starch in hay, expressed as losses of dry matter, ranged from 28 to 15 g kg^-1, depending on the year.     

High-Protein Texturized Products of Defatted Soy Flour, Corn Starch and Beef: Shelf-Life, Physical and Sensory Properties

Selected mixes consisting of Bf [high-beef (29%) low-fat (2.96%)], bf [low-beef (20%) low-fat] and BF [high-beef high-fat (5%)] which incorporated raw beef, defatted soy flour, and corn starch were extruded in a single-screw extruder. The products had no flavor additives and trained sensory panelists detected hay-like, beany or grainy flavors. Bf extrudate was more expanded than BF extrudate and rated least hard by the sensory panel, whereas bf extrudate was least susceptible to lipid oxidation. Bf and bf extrudates showed microstruc-tures with large air cells. All three showed advantages of beef and soy flour in amino acid and fatty acid compositions, respectively, and were microbiologically safe during prolonged storage at 37°C.     

漂白麦草浆细杂组份对阳离子淀粉吸附的影响

本文研究了漂白麦草浆中细杂组份(通过100目,其中大部分是杂细胞,如薄壁细胞,表皮细胞)对阳离子淀粉吸附的影响。 实验表明,漂白麦草浆中细杂组份的比表面积明显大于纤维组份(保留在100目以上)的比表面积。阳离子淀粉优先吸附在比表面积大的细杂组份上。纤维组份的吸附能力受化学环境的影响较细杂组份更为敏感。     

淀粉色浆在手绘加工中的应用

用淀粉色浆代替颜料。扩大了手绘产品的花色品种。文中介绍了用酸性染料色浆绘制真丝绸，用直接染料色浆绘制棉、麻、粘胶丝织物，用分散染料绘制合纤织物等。使用效果好。同时，分别总结了各色浆的调制方法和产品加工要求。     

MALTING AND BREWING SCIENCE: CHALLENGES AND OPPORTUNITIES*,†

Molecular technologies have been developed for the transformation of barley. These technologies complement current methods of barley breeding. In addition, they offer the potential of altering specific components in barley that affect malting quality and of introducing foreign genes, controlling desirable traits, into barley. Application of genetic engineering to improving malt quality factors such as cell wall degradation, protein modification, starch hydrolysis and flavour stability, is discussed. Limitations to the use of this technology for improving malt-related functional properties of barley components such as cell walls and starch granules are also evaluated. Some possible constraints to the utilization of genetic engineering for malt quality improvements are identified.