Rheological properties and gel characteristics of polysaccharides from fruit-bodies of Sparassis crispa

Rheological properties and gel characteristics of Sparassis crispa polysaccharides (SCPs) were investigated under various concentrations, temperature, pH, salt concentrations, and sucrose concentrations. SCP solutions behaved as shear thinning pseudoplastic fluids; apparent viscosity increased with concentrations but decreased with extreme conditions and was highest for 1% SCPs at 80 ℃ under neutral conditions; 5% SCPs solutions formed a hysteresis loop and exhibited thixotropic properties. By oscillatory measurements, SCPs were viscoelastic materials. 0.5% and 1% SCPs solutions exhibited viscous behavior at low frequency and enhanced elastic property with the oscillation frequency increased. With the concentration increased to 3% and 5%, the elastic property was predominant in solutions and exhibited gel-like behavior. SCPs gel textural properties and water holding capacity increased with concentration (to 20%) and decreased with salinity, extreme sucrose, and pH. 10% SCPs gels were optimized at 10% sucrose in neutral conditions. Thus, these results implied SCPs had the potential utilization as a new hydrocolloid source in food industries.     

Derivatized Polysaccharides: Preparation,Characterization, and Application as Bioadhesive Polymer for Drug Delivery

Derivatization of a natural polysaccharide, tamarind seed polysaccharide (TSP), was carried out. Both cationic and anionic derivatives of TSP were prepared, characterized, and their degree of substitution was determined. Films prepared using derivatives were evaluated for their swelling potential and bioadhesive strength. The carboxymethyl and sulfate derivatives were showed higher swelling index and required higher force of detachment compared to native gum thus, indicating that introduction of carboxymethyl, sulfate, and amine groups in TSP can increase the bioadhesive strength. The results suggested that anionic and cationic derivatives can be employed for formulation of bioadhesive drug delivery systems.     

阿魏菇多糖高产菌株筛选的离子束诱变和复合诱变对比研究

为筛选出阿魏菇菌丝体多糖高产菌株，本文进行了阿魏菇多糖高产菌株筛选的离子束诱变和复合诱变对比研究。尝试用打散的阿魏菇菌丝体为靶材，以离子束注入为诱变手段，通过营养缺陷型初筛和摇瓶发酵复筛，获得了2株阿魏菇多糖高产菌株PFPH-1和PFPH-2。其菌丝体多糖产量分别达到551．80mg，L和659．46mg／L，比出发菌株分别提高了46．55％和75．14％。再分别以PFPH．1和PFPH．2为出发菌株，用紫外线和氯化锂进行复合诱变处理，通过高通量初筛和摇瓶发酵复筛，结果发现，菌株1、9和10号比其出发菌株PFPH-1的多糖产量分别减少了27％、38％和37％；菌株17号比其出发菌株PFPH-2的多糖产量减少了28％。在本研究中，紫外线和氯化锂的复合诱变表现出了一定的负效应。     

EFFECT OF METAL IONIC SPECIES AT MINERAL SURFACES ON THE ADSORPTION OF CARBOXYMETHYL CELLULOSE

In this research it was shown that mineral surface metal-lic sites played a decisive role in carborymethyl cellulose(CMC) adsorp-tion, and surface hydrophobicity alone did not have significant effects.Both the carboxymethyl groups and the hydroxyl groups of the CMC par-ticipated in the interaction with mineral surface,with the carboxymethylgroups interacting with metal and metal hydroxyl species, and hydroxylgroups interacting with metal hydroxide species,respectively.     

Production of lepidimoide by an endophytic fungus from polysaccharide extracted from Abelmoschus sp.: identification of the product and the organism producing it

A highly potent allelopathic factor, lepidimoide, was initially extracted from mucilage of germinated cress seeds. Polysaccharide extracted from okra (Abelmoschus esculentum Moench) is considered to have a similar structure to lepidimoide as its repeating unit. We therefore initiated the screening of enzymes capable of degrading okra polysaccharide into lepidimoide from endophytes. We discovered an endophytic fungal strain AHU9748 isolated from Coleus galeatus, which produced an oligosaccharide having similar properties to lepidimoide on thin layer chromatography. The physico-chemical data from ESI-MS, NMR spectra and other analyses also showed the purified product to be identical to lepidimoide. The strain AHU9748 was identified as a fungus belonging to the coelomycetes, closely related to the genus Colletotrichum, based on morphological characteristics and sequence analysis of the 18S rDNA and ITS region.     

超滤膜法浓缩薏苡仁多糖提取液

研究了薏苡仁多糖的超滤膜法提取液浓缩和除小分子杂质过程,并对膜工艺过程的浓差极化及膜污染展开分析,在此基础上对膜清洗进行了尝试,得到适合的膜清洗工艺.在四种陶瓷超滤膜中,截留分子量为150 kDa的超滤膜最适合于薏苡仁多糖提取液浓缩;当压力在0.13~0.21 MPa,温度在20~60℃时,压力和温度的提高均有利于超滤膜通量的增大,但也会加剧膜通量的下降;在超滤过程中,膜污染阻力随着时间的延长而不断增大,而浓差极化效应则不断减小;采用热水,碱洗和次氯酸钠清洗后,膜水通量能够恢复到实验前的水平.     

南瓜、枸杞、芦荟复合发酵果酒的制造

以南瓜、枸杞、芦荟三种汁液为原料生产复合果酒。通过正交实验筛选出一组最佳的混合汁配方,分别选用三种不同的葡萄酒高活性干酵母菌种、三种不同的接种量,在三种不同的温度下进行发酵,经过正交实验,筛选出一组最佳的复合发酵果酒。实验结果表明,接种0.08%的安琪2号葡萄酒高活性干酵母,控温在23℃下发酵的果酒,营养丰富,色香味俱佳。