果胶工艺废水处理方法研究

对采用盐析法提取果胶工艺废水进行小试处理研究。经过几种方案的比较，确定了利用废水中残余的Al(Ⅲ），投加石灰与PAM混凝沉淀，再经炉渣和活性炭脱色的处理方案。据此工艺处理后的废水无色透明，Al(Ⅲ)去除率93．0％，SO4^2-去除率81.1%,CODCr去除率88．2％，达到回用水标准。     

Pectin: A Long-Neglected Broad-Spectrum Antibacterial

First reported in the late 1930s and partly explained in 1970, the antibacterial activity of pectin remained almost ignored until the late 1990s. The concomitant emergence of research on natural antibacterials and new usages of pectin polysaccharides, including those in medicine widely researched in Russia, has led to a renaissance of research into the physiological properties of this uniquely versatile polysaccharide ubiquitous in plants and fruits. By collecting scattered information, this study provides an updated overview of the subtle factors affecting the behaviour of pectin as an antimicrobial. Less-degraded pectin extracted by acid-free routes, we argue in the conclusions, will soon find applications from new treatments for polymicrobial infections to use as an implantable biomaterial in tissue and bone engineering.     

Starting to Gel: How Arabidopsis Seed Coat Epidermal Cells Produce Specialized Secondary Cell Walls

For more than a decade, the Arabidopsis seed coat epidermis (SCE) has been used as a model system to study the synthesis, secretion and modification of cell wall polysaccharides, particularly pectin. Our detailed re-evaluation of available biochemical data highlights that Arabidopsis seed mucilage is more than just pectin. Typical secondary wall polymers such as xylans and heteromannans are also present in mucilage. Despite their low abundance, these components appear to play essential roles in controlling mucilage properties, and should be further investigated. We also provide a comprehensive community resource by re-assessing the mucilage phenotypes of almost 20 mutants using the same conditions. We conduct an in-depth functional evaluation of all the SCE genes described in the literature and propose a revised model for mucilage production. Further investigation of SCE cells will improve our understanding of plant cell walls.     

马铃薯渣综合利用研究现状及进展

马铃薯渣是马铃薯淀粉加工产业的一种副产物,常被作为垃圾废弃掉,造成资源浪费和环境污染。实际上,马铃薯渣中含有许多有价值的成分,具有被开发利用的潜力。目前,马铃薯渣的综合利用主要集中在以下几方面:提取膳食纤维和果胶;制备高蛋白高能量饲料;制备新型黏合剂、胶黏剂和吸附材料;制备燃料酒精、生物质混合燃料和能量气体;制备种曲、醋、酱油及可食性膜等。综述了马铃薯渣目前综合利用的研究现状及进展。     

多孔梯度金属膜在果汁生产中的应用探索

简要叙述膜的发展现状及在果汁中的应用情况,利用多孔梯度金属膜进行苹果汁酶解前的淀粉和果胶过滤试验、果汁澄清通量试验和浓缩汁的巴氏杀菌试验。结果表明:酶解前的果汁经95℃左右的活化处理,利用多孔梯度金属膜在酶解前进行果汁微滤试验后,淀粉和果胶检验均为阴性,表明果汁中淀粉和果胶,经多孔梯度金属膜过滤即可分离除去,不需要淀粉酶和果胶酶的分解,节约大量的酶费用。在巴氏杀菌工段用了多通道的多孔梯度金属膜过滤后巴氏滤液,经检验不能降低后巴氏杀菌的浊度和隔除耐热菌,进行超滤试验发现滤液指标与陶瓷膜过滤还有一定距离。     

Structure and properties of water‐soluble p‐carboxybenzyl polysaccharide derivatives

A series of water‐soluble and water‐insoluble heteroxylans, citrus pectin, and both starch components, amylose and amylopectin, were hydrophobically modified by introducing low amounts of p‐carboxybenzyl groups at constant reaction conditions. The achieved degree of substitution ranged from 0.03 to 0.22. The derivatives were characterized by chemical and spectral analyses. They exhibited tensioactive properties evaluated by various surface‐activity tests. The results indicate a weak surface tension‐lowering effect and low foamability of all derivatives. However, significant emulsifying and protein foam‐stabilizing effects were found for most of the studied derivatives, the most pronounced for the modified pectin and acidic xylans. The rheological behavior of the derivatives was investigated by rotational and oscillation rheometry. The results indicated that the hydrophobic interactions lowered significantly the apparent viscosity of the xylan dispersions and introduced changes, particularly in their flow properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1191–1199, 2000     

籽瓜皮果胶的提取工艺研究

为探究提取分离新疆籽瓜皮中果胶的最佳工艺,采用酸提醇析法探讨了原料预处理、萃取剂的种类、浓度和加入量、萃取温度、时间和浓缩比例等因素对果胶产率的影响.运用正交实验确定最佳的工艺条件为:以细渣状沸水浴灭酶3 min,硫酸为萃取剂,萃取液pH值为1.5,料液比为1:15,萃取2次,萃取温度为90℃,萃取时间分别为2.5 h和1 h,浓缩比例为1/4,冷却后经1:1.5倍乙醇沉淀,果胶产率为19.5%.     

A novel pectin material: extraction, characterization and gelling properties

A novel pectin was acid extracted from chickpea husk (CHP). CHP presented a 67% (w/w) of galacturonic acid, an intrinsic viscosity of 374 mL/g and a viscosimetric molecular weight of 110 kDa. Fourier transform infrared spectroscopy spectrum of CHP indicated a degree of esterification of about 10%. The CHP-calcium system formed ionic gels with a storage (G') modulus of 40 Pa and gel set time (G' > G″) of 3 min at 1% (w/v), and a G' of 131 Pa and gel set time of 1 min at 2% (w/v). The G' of CHP gels was not greatly affected by temperature. The results attained suggest that chickpea husk can be a potential source of a gelling pectin material.     

Phosphated crosslinked pectin as a potential excipient for specific drug delivery: preparation and physicochemical characterization

Pectin was chemically modified with different amounts of trisodium trimetaphosphate (STMP) in aqueous solution (pH = 12), thereby giving a material with reduced water solubility. The physiochemical characterization of this new material was carried out through Fourier transform infrared and thermogravimetric analyses. Phosphated pectin (Pect‐STMP) together with prebiotic (oligosaccharide) were incorporated into an aqueous dispersion of polymethacrylate (Eudragit^® RS 30 D) in order to obtain free films using a casting process (50 °C) on a Teflon plate. The free films were evaluated using water vapour transmission, average swelling index in simulated gastric fluid (SGF) and simulated intestinal fluid, scanning electron microscopy and a diffusion study with theophylline in buffer solution with and without pectinolytic enzyme. The results suggest that the new material can be used in the coating process for oral solid‐reservoir systems, to prevent the premature release of drugs in SGF (pH = 1.2). Furthermore, the presence of both Pect‐STMP and oligosaccharide favours the specific degradation of the pellicle by the action of the enzymes produced by colonic microflora. The material obtained in this work has the potential to be applied in devices for drug delivery in the colon, making possible modified release of drugs. Nevertheless, subsequent colon‐specific experiments in vivo need to be carried out in order to confirm the possible application of this new material. Copyright © 2009 Society of Chemical Industry     

响应面法优化微波辅助萃取柠檬皮中果胶的研究

该文以离子液体[BMIM]Cl(氯化1-丁基-3-甲基咪唑)水溶液为萃取剂,采用微波辅助萃取技术提取柠檬皮中的果胶,系统考察了[BMIM]Cl浓度、萃取温度、萃取时间和萃取溶剂体积等因素的影响,并通过响应面法对提取工艺进行了优化,得出最佳工艺条件为[BMIM]Cl浓度1.0 mol/L,萃取温度88℃,萃取时间9.6 min,每克干柠檬皮用萃取溶剂22.7 mL,在该条件下,果胶的提取率为24.68%,与拟合的二次回归模型预测值基本相符。