草浆碱回收绿液水不溶物对白泥光学性能的影响研究

为了提高制浆造纸碱回收白泥白度,研究了草浆碱回收绿液水不溶物含量对草浆碱回收白泥光学性能的影响.实验结果显示,草浆绿液中的水不溶物是影响白泥白度的主要因素,草浆绿液水不溶物含量越高,白泥白度越低;当浊绿液经滤纸过滤,去除绿液中的水不溶物后,所制备白泥白度增幅达到7.9个百分点;有效降低草浆绿液中的水不溶物含量是降低白泥与商品PCC(沉淀CaCO3)色差的关键.     

草浆白泥碳酸钙对AKD施胶性能影响的探讨

为了了解白泥碳酸钙对AKD施胶性能的影响因素,研究了制备白泥碳酸钙的绿液和生石灰对AKD施胶性能的影响。结果表明:绿液和生石灰都对AKD的施胶性能有抑制作用,且绿液的影响要大于生石灰。除去绿液的水不溶物或生石灰的酸不溶物,能够较好地改善白泥碳酸钙对AKD施胶性能的抑制。     

PET合成过程中低聚物热降解的研究

本文针对某些PET 切片在常规指标合格时,而可纺性不好的现象,对聚合过程中低聚体的热降解进行了研究。发现低聚体的热降解会导致不溶物的生成;同时对不溶物的性质、结构作了探讨。结果表明,低聚体热降解所生成的不溶物对PET 切片的色泽及流动性能、热性能等方面有明显影响,从而找到了影响PET 品质的又一个因素。使长期困扰我们的一些现象得到了解释。     

绿液特性对白泥影响AKD施胶效率的研究

研究绿液特性对其所制备白泥碳酸钙加填纸的AKD施胶效率。结果表明,绿液品质对白泥碳酸钙加填纸的AKD施胶效率有一定影响,随绿液不溶物去除率的提高,所制备白泥加填纸的AKD施胶效率提高。绿液不溶物含量从1360 mg·L-1降低到145 mg·L-1,其所制备的白泥碳酸钙加填纸的Cobb60值从86.1 g·m-2降低到64.8 g·m-2。     

商用大豆分离蛋白可溶絮凝物的制备及其性能研究

本文报道了超声处理制备可溶的商用大豆分离蛋白(SPI)絮凝物。经SDS-PAGE及SE-HPLC分析确认,超声处理可使不溶的SPI组份形成一种可溶的絮凝物,后者包含了原先不溶的大豆球蛋白的碱性亚基及大部分的β-伴大豆球蛋白。与未经超声处理的SPI分散液相比,经超声处理的分散液具有更高的热稳定性及凝胶性能。该研究结果可为商用SPI在食品中的应用提供一定的指导。     

计算两例

一、红液蒸发站单位固溶物蒸发的水量计算采用四效蒸发站,按顺流方式进液蒸发红液,进Ⅰ效时红液浓度为10％(固溶物,下同),离开蒸发站时,红液浓度为52％。出ⅠⅡⅢ效时,红浓浓度依次为11.8％、14.9％、22.2％。求各效中每kg固溶物蒸发的水量。其法如下: 红液进第Ⅰ效的液体组成为:90/10=9kg水/kg     

糖液磷酸气浮提净法的技术要素

(一)加压溶气法气浮分离技术是应用气泡在糖液中的浮升作用将糖液中的不溶物提携分离而被除去。因此,产生气泡的方法是一个重要环节。在糖液磷浮提净工艺中,人们曾研究过多种不同类型的充气方法,至今应用较广泛和较成功的是溶气法。原糖液的磷浮提净,威林逊(Willia-mson)最先研究的充气方法是,以压缩空     

粉状大豆磷脂的制取工艺试验

采用丙酮精制法除去浓缩大豆磷脂中的非磷脂物。试验以质量较差的未漂白浓缩大豆磷脂(含乙醚不溶物5.10％,丙酮不溶物44.4％)和质量较好的漂白浓缩大豆磷脂(含乙醚不溶物0.07％,丙酮不溶物56.6％)进行了工艺比较,各次脱油的油溶剂重量比分别是1:3～4和1:4～5;产品收率分别是44.0％和51.2％,产品的纯度含磷量分别是2.9％和3.07％,换算成磷脂含量(转换系数30)则分别是87.0％和92.1％,乙醚不溶物含量分别是7.98％和0.15％。说明原料的质量尤其是杂质乙醚不溶物的含量对产品的纯度影响很大。将第一次脱油与后几次脱油操作分别在二个串连的装置中进行,当第一次脱油后的静置分层终温降至25～30℃时,此液含丙酮不溶物低于0.8％,下层磷脂徐徐流入25℃左右,快速搅拌下的丙酮溶剂中,立即变成分散的粉粒,清除了倾滗法操作时磷脂结团、结块和粘壁的现象,为实现在密闭装置系统中半连续的工业化生产及安全操作提供了依据。     

气浮法处理玉米淀粉生产装置工艺水的研究

采用加压溶气气浮法来去除玉米淀粉生产装置工艺水中的不溶物.研究了其溶气量和工艺水在气浮槽中的停留时间对工艺水中不溶物去除率的影响,确定了气浮槽最佳工艺条件为:溶气量为52 L/m3,停留时间为7 min.在此条件下,工艺水中不溶物去除率可达60%以上.     

高酸价毛糠油中含蜡量的测定——改进丁酮不溶物测定法

一、引言 目前国内外关于油品的测蜡方法很多,如汽液相色谱法、丙酮不溶物测定法、浊度仪法以及丁酮不溶物测定法等。这些方法对于低酸价的成品油脂和毛糠油很适用,尤其是丁酮不溶物测定法,测试效果较为理想。日本沃利查油化公司对丁酮不溶物测定法作出的定义是:“在含饱和水的丁酮溶液中,米糠油的不溶物的重量,对米糠油的重量的百分比称为含蜡量。”我们在实验室中使用这一方法,对较高酸价的毛糠油,即酸价大于40mgKOH/g的毛糠油,进行含蜡量的测定时,发现误差较大。我们对丁酮不溶物进行了分析,结果表明丁酮不溶物中游离脂肪     

白泥碳酸钙光学性能的影响因素

为了了解影响白泥碳酸钙的光学性能的因素,本文研究了白泥碳酸钙制备中原料对其光学性能的影响。结果表明,在白泥碳酸钙的制备中生石灰对其光学性能的影响要大于绿液;生石灰中酸不溶物对光学性能影响明显,对白度的影响可达3.35%,对色度影响达41%。     

黑小麦功能性低聚糖的分离与组成分析

研究黑小麦麸皮功能性低聚糖的分离制备方法,并对其组成进行分析。采用木聚糖酶酶解黑小麦麸皮不溶性膳食纤维,所得酶解液经活性炭柱层析进行分离,并利用液相色谱和离子色谱对分离组分的单糖组成、低聚糖组成以及阿魏酰基团进行检测。结果表明,活性炭柱层析的水洗组分(WO)、不同浓度醇洗组分(EO)的低聚糖均主要由阿拉伯糖和木糖组成,为阿拉伯低聚木糖。其中,WO含有结合态阿魏酸,为阿魏酰低聚糖。WO的低聚糖聚合度较高,为DP 4~7;醇洗组分EO的低聚糖聚合度较低,为DP 2~4。     

HPLC法测定茶树花中可溶性糖、儿茶素和游离氨基酸

采用高效液相色谱法测定茶树(Camellia sinensis)花中可溶性糖、儿茶素和游离氨基酸的含量。结果表明：茶树花中含有216.85mg/g可溶性糖,其花冠、雄蕊群和雌蕊群部分(F-1)及花托、萼片和花梗部分(F-2)的含量分别为250.945mg/g和112.65mg/g;茶树花中总儿茶素含量为37.03mg/g,且F-2中的含量(46.90mg/g)高于F-1(30.88mg/g);茶树花中含有包括茶氨酸在内的16种游离氨基酸,含量为10.87mg/g,虽然F-2中游离氨基酸的种类较少,但其含量(16.47mg/g)显著高于F-1(10.59mg/g)。     

Effects of enzymatic treatment conditions on dietary fibre content of wheat bran and use of cellulase-treated bran in cookie

A commercial cellulase preparation (Viscozyme Cassava C) was employed to process wheat bran to improve the ratio of insoluble to soluble dietary fibre. The effects of initial moisture content, enzyme dosage, and incubation time on the content of soluble and insoluble fibre during the enzymatic treatment were investigated. The appropriate conditions for the cellulase treatment were initial moisture content of 0.75 g water g⁻¹ dry matter, enzyme dosage of 9 U g⁻¹ dry matter and incubation time of 120 min under which the ratio of insoluble to soluble fibre of wheat bran was lowered by 42%. Untreated and cellulase-treated wheat bran was incorporated into cookies at levels of 0%, 20%, 30%, 40% and 50%. Cookie with 50% cellulase-treated bran showed 21% lower ratio of insoluble to soluble fibre as well as 14% lower hardness and 13% higher overall acceptability than sample with the same amount of untreated bran.     

Losses of nutrients and anti-nutritional factors during abrasive decortication of two pearl millet cultivars (Pennisetum glaucum)

Losses of nutrients such as starch, lipids, proteins, iron and zinc as well as phytase activity and of recognised anti-nutritional compounds (some insoluble fibres, iron-binding phenolic compounds and phytates) were determined following abrasive decortication of grains from two pearl millet cultivars (Gampela and IKMP-5) with different composition cultivated in Burkina Faso. In both cultivars, abrasion of the starchy endosperm started when about 12% of the dry matter had been removed from grains but lipid and protein losses followed the loss of dry matter. Zinc loss (%) was lower than that of iron; however, both were higher than dry matter losses. By contrast, phytate loss was lower than dry matter loss. Interestingly, decortication led to significant losses in fibres and iron-binding phenolic compounds with different level depending on the cultivar. Changes in phytase activity also differed in the two cultivars (42% and 11% losses of phytase activity in grains from Gampela and IKMP-5 cultivars, respectively, at 12% of abrasion). Hence, decortication of pearl millet grains does not decrease lipid and protein contents but does considerably decrease some anti-nutritional factors (part of the fibres and iron-binding phenolic compounds). However, as mineral contents and particularly iron content decreased while phytate content remains high, decortication may be insufficient to increase Fe and Zn bioavailability.     

Digestibility by lambs of water-stressed alfalfa as determined by total collection or internal markers

A lamb digestion trial was conducted to compare the ability of internal markers to predict digestibility of alfalfa. Lambs were fed alfalfa hay grown with varying amounts of water stress where water per harvest ranged from 10 to 20 cm/ha and yield ranged 1400 to 4200 kg/ha. In vivo dry matter digestibility was most highly correlated with digestibility determined using acid detergent fiber insoluble ash (r = .80) followed by acid insoluble ash (r = .69). In vivo digestibility of the fibrous components was most highly correlated with digestibility determined by acid detergent insoluble ash and indigestible neutral detergent fiber followed by acid lignin and acid insoluble ash.     

Effect of pasteurisation on the chemical composition of liquid whole egg V.—Isolation and examination of a complex lipoprotein from pasteurised liquid egg

A high molecular weight substance isolated from the insoluble proteins of pasteurised liquid whole egg was found to be a complex lipoprotein containing 70 % lipid and 30 % protein. The lipid portion was a mixture of several different groups and the apoprotein was an extremely insoluble material with an amino acid composition that did not exactly match that of any egg protein reported in the literature but closely resembled that of vitellenin. It is postulated that this lipoprotein was derived from the low density fraction of egg yolk. A substance of lower molecular weight that was also separated from the inert fraction of insoluble proteins by gel filtration was tentatively identified as one of the lipovitellins.     

含氧化叔胺侧基的水溶性酚醛树脂激光成像热敏膜的制备

通过两步法制备改性酚醛树脂。首先,利用环氧酚醛树脂F-48与二甲胺反应,得到叔胺化酚醛树脂,叔胺化树脂被双氧水氧化后得到最终目标产物。该新型树脂易溶于水。然而,当加热到160℃时这种树脂就会变得不溶于水。通过DSC和TGA测试氧化叔胺树脂的热性能。实验制备了一种含有该树脂和红外染料的热敏膜,具有激光诱导成像功能。结果表明,这种氧化叔胺树脂可用于研发免化学处理热敏CTP版材。     

Effect of pasteurisation on the chemical composition of liquid whole egg. III.—Effect of staling and freezing on the protein fractionation patterns of raw and pasteurised whole egg

Two particular fractions of the soluble proteins were consistently reduced by heating liquid egg for 5 min at 150°F. These fractions were quantitatively greater in the soluble proteins from frozen egg. The soluble proteins appeared to be more stable to heat in eggs that had been stored for 15 days at 70°F than in new-laid eggs. Unfrozen new-laid and stale egg and frozen new-laid egg all showed an increase in insoluble material after pasteurisation, and frozen egg contained more insoluble materials than unfrozen egg. Gel filtration showed that the proportion of compounds of high molecular weight in the insoluble proteins was markedly increased by pasteurisation and even more markedly increased by freezing.     

Effects of spray-drying and freezing on the proteins of liquid whole egg

Commercial pasteurised liquid whole egg was spray-dried, both alone and mixed with liquid milk, and some of it was frozen. Paper electrophoresis revealed that lipoprotein fractions from the pasteurised liquid egg were mainly immobile, in contrast to unpasteurised new-laid egg which contained both mobile and immobile lipoprotein fractions. The major difference between the soluble proteins of the commercial chilled pasteurised liquid egg and those of the same egg after freezing and thawing was the presence, in the former, of an inert lipoprotein fraction, amounting to 3.6% of the total egg solids and containing 88% lipid. The “soluble” proteins of spray-dried egg and egg-milk mixture also included large “inert” lipoprotein fractions eluted with the void volume. They contained 72–81% of lipid and accounted for 7–13% of the total egg solids. Larger fractions were eluted by the stronger salt buffer solutions and by hydrochloric acid from the dried egg-milk mixture than from the dried egg, and these were probably derived from the milk. All the spray-dried samples possessed the “inert insoluble” protein fraction characteristic of liquid egg, and the presence of a high molecular weight lipoprotein fraction was confirmed in each case. The “insoluble proteins” of the spray-dried samples had higher protein contents than those from the original chilled liquid egg and the thawed frozen egg.