A Consistent Inoculum System to Study the Fermentation of Non-starch Polysaccharides

A variable in batch culture fermentation systems for studying the fermentation of polysaccharides is the faecal inoculum. A commercial bacterial bead preservation system (Microbank^TM) has been used for the long-term storage of faecal inoculum. The inoculated beads are stored at -70°C for up to 3 months and retain their ability to ferment pectin, as measured by production of short-chain fatty acids. A recovery medium is used for 27 h followed by culture in a standard medium for 48 h. Such a system offers a significant advantage over the present method of using fresh faeces on each occasion both in terms of ease of use and consistency of the inoculum. This allows for repeatable fermentation experiments over prolonged periods of time. © 1997 SCI.     

黑麦非淀粉多糖胶在制备香肠中的应用

为了研究黑麦非淀粉多糖(NSP)胶在香肠中的应用,以黑麦NSP胶、淀粉和肥猪肉添加量为因素,以黑麦NSP香肠咀嚼性为指标,通过单因素试验及响应面设计方法研究确定其在香肠中的最佳添加量为黑麦NSP胶用量2.44g、淀粉添加量1.55％、肥猪肉用量27.8％,在此条件下制备出的香肠咀嚼性为5472.68 Nomm.由感官评定玫瑰图可以得出黑麦NSP胶添加量对香肠的硬度和咀嚼性有显著影响,能够减小香肠产品的硬度,增强咀嚼性.本研究显示了黑麦NSP可以用于生产品质优良的低脂型香肠.     

水-酶连续提取百合非淀粉多糖工艺研究

研究了热水和果胶酶连续提取百合鳞茎中非淀粉多糖的工艺条件。首先利用Box-Behnken实验设计及响应面分析确定热水提取百合非淀粉多糖的条件;再经单因素实验与正交实验优化果胶酶提取水提百合渣中非淀粉多糖的工艺参数。结果表明,水-果胶酶连续提取百合非淀粉多糖的最佳工艺条件为:温度62℃、液料比19∶1,水提4h后,剩余残渣中加入果胶酶（酶添加量1800U/g）于温度30℃、pH5.5的条件下酶解20min。在此条件下,百合非淀粉多糖的得率为8.63%。      

鹰嘴豆非淀粉多糖的分离纯化及结构表征

提取鹰嘴豆中的粗多糖,通过酶处理和Sevag法除去多糖中的淀粉和蛋白质,经DEAE-52纤维素柱和Sephadex G-75凝胶柱分离纯化分别得到鹰嘴豆非淀粉中性多糖和酸性多糖,并通过紫外光谱、气相色谱、红外光谱、扫描电镜测定其性质和单糖组成。结果表明：鹰嘴豆非淀粉多糖在260 nm和280 nm波长处均无吸收峰,表明两种多糖均不含核酸、蛋白质以及肽类等;气相色谱测定表明鹰嘴豆非淀粉中性多糖单糖组成的物质的量比为鼠李糖∶岩藻糖∶阿拉伯糖∶木糖∶甘露糖∶半乳糖∶葡萄糖=2.48∶1∶3.92∶0.87∶32.82∶18.79∶28.06,鹰嘴豆非淀粉酸性多糖单糖组成物质的量比为鼠李糖∶岩藻糖∶阿拉伯糖∶木糖∶甘露糖∶半乳糖∶葡萄糖=2.22∶1∶3.92∶2.10∶5.92∶15.99∶8.57（均以岩藻糖为标准）;红外光谱测定表明二者均有多糖的特征吸收峰;扫描电镜显示鹰嘴豆非淀粉中性多糖呈线形结构而鹰嘴豆非淀粉酸性多糖呈卷曲的片状结构。     

药食同源植物丁香各部位抗营养因子分析

结合食品饲料安全国家标准以及文献方法,对药食同源丁香植株花蕾、果实、枝、叶部位的抗营养因子进行研究分析.结果表明:丁香花蕾、果实、枝、叶各部位的主要抗营养因子含量均处于食品或饲料的正常范围.植酸含量果实最低为33.24 mg/g.胰蛋白酶抑制剂活性各部位较接近,其中果实含量最高为44.2 mg/g.植物凝集素含量叶最低...     

水溶性非淀粉多糖的提取纯化技术进展

近几年来,植物水溶性非淀粉多糖(NSPS)在食品和医药产品中的应用取得了很大的发展,已经成为能深入研究的有趣课题。水溶性NSPS具有独特的流变特性,能够与水形成粘度由低到高的溶液,可用于饮料、烘焙、冷冻等各种食品中,以改善质地,稳定食品混合物。水溶性NSP在制药工业中也被广泛用作药物输送的封装基质,以及作为具有预防作用的生物活性材料,如抗癌和抗糖尿病。水溶性NSP在促进肠道微生物群生长和支持短链脂肪酸生产方面的益生元作用是迄今为止最有价值的科学发现。由于其使用需求不断增加,为了获得更高的得率,降低成本,缩短提取时间,扩大提取工艺规模,探索并应用了先进新颖的提取技术,包括采用超声波和微波提取水溶性NSP,克服了传统提取方法的一些局限性。为了减少损失和降低脱蛋白对提取水溶性NSP生物活性的负面影响,人们探索了绿色脱蛋白技术,如使用冻融技术替代常用的化学方法。绿色的水溶性NSP脱蛋白纯化方法将使提取的物质更安全地用于食品和医药产品中。     

百合中水溶性非淀粉多糖的提取、分离和纯化

研究使用或未使用蛋白酶从百合鳞茎中提取和分离水溶性非淀粉多糖(WSNSP)。利用SepharsoseCL-6B和SephadexG-100凝胶过滤色谱分离了用蛋白酶提取的WSNSP,测定WSNSP的比浓粘度为89.168cm3/g,相对分子质量较低为21448.8。此外,还利用离子交换和凝胶过滤色谱纯化了未使用蛋白酶提取的WSNSP,发现一些多糖与蛋白质结合在一起,即糖蛋白。     

MORPHOLOGY AND CHEMICAL COMPOSITION OF BARLEY ENDOSPERM CELL WALLS

Cell walls have been isolated from barley endosperm and found to contain a microfibrillar phase which is embedded in an amorphous matrix. The microfibrillar phase probably consists of cellulose, together with tightly bound arabinoxylan and polysaccharides rich in mannose. The matrix material is arabinoxylan (approx. 25%) and β-glucan (approx. 75%). Pectic polysaccharides are absent from the isolated cell walls. After successive removal of the matrix polysaccharides with water and 1-M NaOH, only 6% of the wall remains. The intra-cellular surfaces of the wall fragments are extensively pitted, probably as a result of adpression of starch granules into the cell wall material during endosperm development. Although polysaccharides are the major components of the cell walls, some nitrogen (less than 1%) is present. Phenolic compounds may also be wall constituents, but hydroxyproline could not be detected.     

膳食纤维的定义、分析方法和摄入现状

本文主要论述膳食纤维的定义、分析方法以及人群摄入情况.中国营养学会将膳食纤维定义为不易被消化酶消化的多糖类食物成分(主要来自于植物的细胞壁),包含纤维素、半纤维素、树脂、果胶及木质素等.这种定义和FAO/WHO对膳食纤维狭义上的定义基本一致.而欧盟将其定义为具有3个或以上单体链节的碳水化合物聚合物,在人体小肠中不能被消化或吸收,包括天然存在于消费食物中的可食用的碳水化合物,由食物原料经物理、酶或化学法获得的碳水化合物,对健康表现出有益的生理作用的人造碳水化合物聚合物.根据现有定义,适用的主要分析方法有非酶重量法、酶重量法、酶化学法等.这些方法都是借鉴于AOAC方法.     

Polyamines and cell wall organization in Saccharomyces cerevisiae.

Cells of Saccharomyces cerevisiae 179-5, an ornithine decarboxylase mutant (spe-1), showed several ultrastructural abnormalities when cultivated in the absence of polyamines. Besides the appearance of microvacuole-like spaces in the cytoplasm and of deformed nuclei, the most important alterations seemed to be located in the cell wall, which was thicker and of heterogeneous texture, and in the cell membrane, of irregular contour. These modifications could not be evoked by general stress conditions elicited by lack of nutrients. The relative levels of cell wall polysaccharides were altered in polyamine-deprived organisms, giving an envelope with increased mannan and decreased glucan content; this cell wall was incompletely attacked by the lytic enzyme zymolyase. Polyamine depletion led also to some abnormalities in the budding pattern. The above observations suggest the involvement of polyamines in the correct structure and organization of the yeast cell.     

比较基因组揭示广西酸菜乳杆菌碳水化合物活性酶谱

微生物中的碳水化合物活性酶(carbohydrate active enzymes,CAZymes)具有降解植物组织的作用,相对于真菌,目前对于乳杆菌的CAZymes研究还比较少.该研究从广西酸菜中筛选获得了3株产CAZymes的乳杆菌,并通过二代测序技术比较其编码基因.16S rRNA测序结果表明3株乳杆菌分别是La...     

碱法破壁-酶法提取葡萄酒废酵母细胞壁多糖的工艺研究

以工业发酵产生的葡萄酒废酵母泥为材料,过筛法除去葡萄果皮、果籽等杂质后,以细胞破壁液蛋白质含量、多糖提取率为评价指标,通过单因素试验和正交试验对碱法破壁-酶法提取细胞壁多糖工艺进行优化,以期提高多糖提取率。结果表明,最佳工艺条件为细胞破壁碱（KOH）处理温度为60 ℃,碱（KOH）质量浓度为70 g/L,处理时间为1.5 h,80 kHz超声辅助;酶法提取多糖最佳工艺为酶作用温度50 ℃,酶解时间1.5 h,中性蛋白酶添加量0.3%,初始pH值7.0。在此优化条件下,葡萄酒废酵母多糖提取率为21.08%。     

生物技术法处理对花生粕饲用品质影响的研究

花生粕存在黄曲霉毒素B_1(AFB_1)易超标、非淀粉多糖含量高和蛋白质品质不佳等缺陷,利用微生物(枯草芽孢杆菌、酿酒酵母、乳酸片球菌)发酵结合复合酶制剂处理花生粕,可以综合改善其饲用品质。研究表明:处理后花生粕中AFB_1的去除率为94.6%,非淀粉多糖含量由30%降低至10.5%,蛋白质含量由47.8%提高至61.5%,大分子蛋白明显降解为小分子蛋白,小肽含量由5.36%提高至25.21%,必需氨基酸总量提高了19.67%,乳酸含量由0.7%提高至2.8%。经过生物技术法处理,花生粕的饲用品质得到了明显改善。     

Cultivar and Maturity Effects on Muskmelon ( Cucumis melo) Colour,Texture and Cell Wall Polysaccharide Composition

Cell wall polysaccharides (CWP) of two types of melons were isolated and purified. Fractionations were performed using cyclohexanetrans-1,2-diamine tetraacetate (CDTA), Na₂CO₃, guanidinium thiocyanate (GTC) and KOH. Alditol acetate derivatives of neutral sugars from each CWP fraction were prepared and analysed by gas chromatography. Trifluoro-acetic acid insoluble fractions were analysed colorimetrically and uronic acid was determined. The CDTA and Na₂CO₃ fractions were found to be composed of typical pectic materialscontaining primarily galacturonic acid with the neutral sugars arabinose, galactose, rhamnose and a smaller amount of xylose. As maturity increased, CDTA fraction yields increased, though total neutral sugar CWP compositions decreased. GTC and KOH fractions were typical of hemicellulose, and contained principally xylose, glucose, galactose, mannose and fucose, with very small amounts of uronic acid, arabinose and rhamnose. The residues contained principally glucose and galactose, with smaller amounts of mannose, xylose, arabinose and fucose. With the exception of xylose and glucose, all neutral sugars decreased significantly during ripening in both the Cantaloupe and Honey Dew melons. Total uronic acid did not change as maturity increased, except for Cantaloupe, where total uronic acid decreased from the ripe to overripe stages. Relationships between firmness, drip loss and other composition measurements, as well as the total CWP sugar composition, were also determined. Only the CDTA fraction yields were negatively correlated with the changes in firmness of both melons and positively correlated with changes in drip loss as maturity increased.     

Faecal Composition and Nitrogen Excretion of Rats Fed on Diets Containing Sweet Lupin (Lupinus angustifoliusL) or its Fractions

Five N balance studies were conducted to determine the faecal composition and N excretion of feeding raw Lupinus angustifolius seed meal and its fractions for growing rats using a semi-synthetic lactalbumin-based diet as control. Diets were formulated to have equal amounts of energy. The protein was incorporated at the level of 10% bulk and contained unsupplemented lupin seed meal (LMU) and fully supplemented lupin seed meal (LMFS) at 360 g kg⁻¹ diet, aqueous extract non-dialysed (LPAND) at 196 g kg⁻¹ aqueous extract dialysed soluble at pH 7·0 (LPAD) at 148 g kg⁻¹ aqueous extract dialysed insoluble at pH 7·0 (LPADI) at 124 g kg⁻¹, buffer dialysed soluble at pH 7·0 (BUSOL) at 136 g kg⁻¹, buffer dialysed insoluble at pH 7·0 (BUDI) at 119 g kg⁻¹ and lupin meal residue after aqueous and buffer extraction (LMR) at 170 g kg⁻¹ diet. Rats were pair-fed for 10 days with all the above diets which had been supplemented with essential amino acids up to the target requirements for rats. Faecal wet and dry weight were increased in rats fed on LMU, LMPS and LMR diets compared to those obtained from the control diet based on lactalbumin (milk protein) LACT. The higher faecal weight was largely due to water content. The higher faecal N excretion observed in LMU, LMFS, LPAND, LPAD, BUSOL, BUDI and LMR compared to that of LACT diet was significantly lower and thus which was assumed not to be due to a decrease in the digestibility of the dietary protein, which was over 90% as compared to that in the control group. Analysis suggested that an increase in endogenous N excretion is involved in the rise of its excretion in the faeces, and indicates a long-term effect of this seed as a protein and or fibre source in monogastrics.     

五种单体酶配伍对肉仔鸡生长性能及非淀粉多糖消化率的影响

研究在小麦基础日粮中添加五种单体酶制剂(木聚糖酶、β-葡聚糖酶、纤维素酶、植酸酶和甘露聚糖酶)对1～21日龄肉仔鸡生长性能和非淀粉多糖(NSP)消化率的影响。试验将624只1日龄肉仔鸡按均匀设计方法随机分成13组,其中第13组为对照组,各处理组日粮为上述五种单体酶制剂的不同配伍添加在基础日粮中组成。结果表明,五种单体酶制剂的不同配伍能不同程度提高肉仔鸡生长性能和NSP的消化率。其最佳的配伍水平为:木聚糖酶450 u·kg-1、β-葡聚糖酶47 u·kg-1、纤维素酶333 u·kg-1、植酸酶135u·kg-1、甘露聚糖酶153 u·kg-1。