酶法提取分离甘薯渣可溶性膳食纤维的研究

目的:提高甘薯渣中可溶性膳食纤维含量.方法:以干燥、粉碎的甘薯渣为原料,利用纤维素酶将原料中不可溶性膳食纤维转化为可溶性膳食纤维,同时用淀粉酶,糖化酶和碳酸钠去掉杂质,酒精沉淀,从而获得可溶性膳食纤维.结果:在单因素基础上通过正交实验确定最佳酶法提取可溶性膳食纤维条件为淀粉酶100μl,纤维素酶90μl,pH为5.6,酶作用时间为3 h,反应温度为40℃.国标法提取的甘薯渣中可溶性膳食纤维含量为10.06%,正交实验优化提取条件后得到的甘薯渣可溶性膳食纤维含量为25.52%,提高了15.46%.结论:甘薯渣可溶性膳食纤维含量受纤维素酶,淀粉酶,酶提取时间,酶反应pH,反应温度等提取工艺影响.     

脱脂对不同生长期苜蓿膳食纤维含量及其提取得率的影响

目的：研究脱脂对苜蓿膳食纤维含量、构成及其提取得率的影响,为该方法在苜蓿膳食纤维提取中的合理应用提供科学依据。方法：以初花期和结荚期苜蓿草粉为原料,研究脱脂前后苜蓿草粉中膳食纤维含量、构成及其提取得率的变化规律。结果：苜蓿膳食纤维以水不溶性膳食纤维（IDF）为主,开花后苜蓿IDF含量占膳食纤维总量（TDF）的90%以上;脱脂后的初花期和结荚期苜蓿草粉中,IDF含量分别达72.88%、73.62%,比脱脂前分别提高61.38%、38.12%;IDF在TDF中的比例分别由90.09%、92.82%提高至95.19%、95.71%,IDF提取得率分别达61.52%、72.11%,比脱脂前分别提高69.94%、48.62%;脱脂过程中水溶性膳食纤维（SDF）流失严重、含量降低,SDF提取得率下降92.68%和92.29%。结论：脱脂方法适用于结荚期苜蓿IDF提取原料的前处理,但不适于苜蓿SDF的提取。     

火龙果果皮中可溶性膳食纤维的提取方法

火龙果(Hylocereus undulatus)果皮可以作为一种优良的膳食纤维来源,且其膳食纤维具有良好的理化性能。为提高火龙果果皮的综合利用水平,该研究以火龙果果皮为原料,首先采用纤维素酶水解法对火龙果果皮中的可溶性膳食纤维进行提取,然后采用单因素试验和响应面法优化酶提取工艺。结果表明,纤维素酶法提取火龙果果皮中可溶性膳食纤维的优化工艺条件为:纤维素酶浓度0.54%,酶解温度50°C,pH5.2。在此条件下,可溶性膳食纤维的提取率可达19.81%;膳食纤维的持水力为31.25 g·g~(–1),溶胀性为29.11 m L·g~(–1)。     

马铃薯渣中膳食纤维提取工艺的优化

目的：以马铃薯渣为原料,探究提取马铃薯渣中膳食纤维的最佳工艺条件。方法：通过生物法 酶法、超声波裂解、高速剪切等技术提取马铃薯渣中所含的膳食纤维,通过单因素试验和正交试验分析试验数据。 结果：提取膳食纤维的最佳工艺条件为酶解pH为5、酶解温度45℃、酶添加量30U/g、酶解2.5h。结论：本研究膳食纤维的提取率达25.87%,并测得持水力和膨胀力分别为7.1g/g、7.5mL/g,该工艺条件可有效提取马铃薯渣中的膳食纤维。     

从罗汉果渣中提取水不溶性膳食纤维的研究

采用化学法、酶法、酶与化学结合法从罗汉果渣中提取水不溶性膳食纤维,并且对三种提取方法所得的水不溶性膳食纤维产品特性进行了分析比较。研究结果表明,采用酶与化学结合法提取到的水不溶性膳食纤维产品纯度最高、生理活性最好,产率为87.15％,蛋白质含量为2.03％,持水力与膨胀力分别为3.807 g·g-1和1.69 mL·g-1。但从成本和实用方面考虑,还是以化学法为宜。     

膳食纤维的提取、食药价值及综合利用的研究进展

从膳食纤维的提取、药理功能及综合利用等方面综述了膳食纤维的研究进展,为膳食纤维的研究和开发提供科学依据。     

酶解法提取甘薯茎叶中可溶性膳食纤维的研究

通过单因素以及正交实验来探讨脂肪酶、淀粉酶和木瓜蛋白酶的加入对提取甘薯茎叶中水溶性膳食纤维的影响,并在单因素基础上对提取工艺进行正交优化,得出酶法提取的最佳工艺条件是脂肪酶添加量为0．015 g·100 mL-1,淀粉酶添加量为0．035 g·100 mL-1,木瓜蛋白酶添加量为0．075 g·100 mL-1,其中正交实验中影响因素为淀粉酶＞蛋白酶＞脂肪酶.水溶性膳食纤维的最佳提取率为1．285％.提取得到的甘薯茎叶中水溶性膳食纤维纯度高,持水力为787％,溶胀力为4．10 mL·g-1,产品具有良好的性状.     

双酶法制备玉米皮膳食纤维的研究

采用蛋白酶和淀粉酶结合水解制备玉米皮膳食纤维,通过正交试验确立了玉米皮膳食纤维的双酶法制备工艺。双酶法制备的玉米皮膳食纤维的产率为59.4%,膳食纤维的蛋白质量分数为0.82%,淀粉质量分数为1.42%,灰分为0.4%,水分质量分数为8.6%,持水力为5.9±0.4 g.g-1。     

响应面优化沙棘果渣膳食纤维提取工艺及应用性质评价CSCD

为实现林下资源加工废弃物再利用,本实验以沙棘果渣为原料,采用超声辅助酶法,分别对纤维素酶添加量、超声温度、超声时间、料液比四个因素进行膳食纤维提取效果影响分析,以可溶性膳食纤维(soluble dietary fiber,SDF)和不可溶性膳食纤维(insoluble dietary fiber,IDF)得率比值为指标,通过响应面法对主要参数进行优化,并分析所获膳食纤维应用性质。结果得出,在最优条件纤维素酶添加量为5%,60℃下超声50 min时,SDF/IDF为0.21±0.01,总膳食纤维(total dietary fiber,TDF)溶胀力和持油力较高,分别为3.12±0.13 mL/g、(4.47±0.41)%,且对胆固醇的吸附效果良好。因此,超声辅助酶法能有效提高产物提取效率,对推进沙棘副产物资源的开发利用具有一定意义。     

刺梨果实膳食纤维积累动态及其对遮光的反应

刺梨果实是优质膳食纤维的良好来源。该研究以‘贵农5号’刺梨果实为材料,测定了果实发育过程中膳食纤维的含量、组分变化及其对光照的响应特征。结果表明:(1)在刺梨果实的整个发育过程中,总膳食纤维和不溶性膳食纤维含量在花后40 d之前的幼果期更高,并随着果实的快速发育持续下降,至成熟时分别约占果实干重的24%和16%,而可溶性膳食纤维含量在果实发育过程中变化平稳,一直维持在干重的8%左右。(2)果胶在花后20 d之前有一快速积累过程,至果实成熟时纤维素和半纤维素为膳食纤维主要组分,约占总膳食纤维的60%;花后60 d之前是刺梨果实膳食纤维积累的主要时期。(3)刺梨果实总膳食纤维、不溶性膳食纤维中单糖组分主要以半乳糖、葡萄糖为主,而可溶性膳食纤维中单糖组分主要为甘露糖,两类膳食纤维间表现出较大差异。(4)果实套袋遮光不同程度促进了刺梨果实总膳食纤维、可溶性膳食纤维、总果胶、原果胶的积累,尤其是100%遮光的效应更明显,但对果实中不溶性膳食纤维、纤维素、木质素、可溶性果胶的积累影响并不显著。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.