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.     

Metabolism of dietary (Acetyl-1-14c)-plant cell walls in the rat intestine

To determine a fate of acetyl groups in intact dietary plant cell walls (PCW) spinach cells were labelled using [1-¹⁴C]acetate as a precursor and the PCW isolated. The (acetyl-¹⁴C)-PCW were fed to rats by garage and the ¹⁴C traced in the rat gut and in the body tissues and excreta of the rat. Some label was solubilised during passage through the upper intestine of the rat, and subsequently incorporated into the body tissues of the rat. A small amount of the radioactivity was excreted as CO₂ (4%) and in urine (<1%). (Acetyl-¹⁴C)-PCW which reached the caecum was solubilised and some [¹⁴C]acetate released. The solubilised ¹⁴C was incorporated in liver tissue mainly as amino acid present in protein.     

Metabolism and fate of dietary (U-14C)-labelled spinach cell walls in the rat

Using uniformly ¹⁴C-labelled spinach (Spinacia oleracea L) plant cell walls (PCW) the metabolism of PCW can be followed in a defined manner in the rat. Only 10% of the ¹⁴C was recoverable in the gut contents and faeces 18 h post-gavage. Two percent of the ¹⁴C was excreted in urine and 25% excreted as CO₂. ¹⁴C was found in all tissues of the body but was most concentrated in the adrenal glands, colon and caecum. The ¹⁴C was also present at moderately high concentration in the liver pelt, and owing to their larger size, these tissues accounted for a high percentage of the total ¹⁴C. In the liver the ¹⁴C was predominantly associated with phospholipid, whereas in the pelt it was present in protein and in fatty acid residues esterified to cholesterol. Dietary PCW material is extensively fermented in the caecum and colon. Also, the products of fermentation are a source of energy and important structural precursors of lipids and proteins for the animal.     

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%。      

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.     

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,微凝血试验中果实和叶表现出微弱的凝血反应。单宁酸含量枝最低,草酸含量花蕾最低。可溶性非淀粉多糖含量果实最低,含量为0.278 mg/g。从几类主要抗营养因子含量来看,各部位含量均较接近,且各抗营养因子在各部位中的含量趋势都有所不同且各有高低。     

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。     

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。     

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...     

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.     

绿芦笋木质化过程中细胞壁多糖与酚类物质变化研究

以绿芦笋栽培品种Mary Washington 500为试验材料，采用HPLC分析方法，研究了常温贮藏条件下，绿芦笋细胞壁多糖、酚类物质和木质素含量的变化。结果表明，随贮藏时间延长，绿芦笋细胞壁半纤维素的主要降解物木糖、岩藻糖残基增加了211．2％，纤维素的主要降解物葡萄糖残基增加了329．3％，木质素含量增加了280．3％。木质素合成前体物中，香豆酸含量最高，其次为咖啡酸和阿魏酸，三者的含量变化与木质素合成密切相关。     

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.     

植物细胞壁中伸展蛋白的研究

首先测定8种蔬菜细胞壁中的羟脯氨酸含量,研究结果表明:豆皮、豆荚、花粉、胡萝卜根、油菜叶柄、芹菜叶柄、青菜和洋葱细胞壁中羟脯氨酸的含量分别为6.02μg/mg、3.30μg/mg、1.74μg/mg、1.53μg/mg、0.64μg/mg、0.52μg/mg、0.42μg/mg和0.31μg/mg。然后通过CM-纤维素柱和Sephadex G-75柱色谱纯化豆渣细胞壁中的伸展蛋白。用CM-纤维素柱色谱纯化豆渣细胞壁蛋白时,得到3个组分,即S1、S2和S3;对S2组分进一步采用Sephadex G-75柱色谱纯化,得到S2a、S2b和S2c,并对S2c组分进行单糖组分分析,S2c中的单糖以阿拉伯糖和半乳糖为主,它们的摩尔之比为21∶。     

1-甲基环丙烯对硬溶质型桃果实细胞壁多糖降解特性的影响

以硬溶质型桃"晚湖景"为试材,20℃下用1μL/L 1-甲基环丙烯(1-MCP)密闭处理24h,研究1-MCP处理对细胞壁降解过程中多糖组分变化、单糖解离特性以及细胞壁多糖降解相关酶的影响。结果表明:1-MCP处理可以明显抑制硬溶质型桃果实硬度的下降,降低乙烯释放量。1-MCP处理的硬溶质型桃果实中CDTA-2、Na2CO3、KOH和CWM-残渣组分在贮藏过程中下降速率都明显低于未处理果。1-MCP处理能延缓CDTA溶性果胶多糖的解离。同时还抑制了Na2CO3溶性果胶多糖中半乳糖醛酸和鼠李糖构成的主链和阿拉伯糖、半乳糖支链的降解,对半纤维素和纤维素多糖成分降解有一定程度的抑制作用。1-MCP处理可能通过抑制参与细胞壁多糖降解相关酶的活性,从而抑制硬溶质型桃果实细胞壁多糖降解及单糖解离,达到延缓果实软化的目的。     

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%。     

Ripening‐related changes in the cell walls of olive (Olea europaea L.) pulp of two consecutive harvests

Olive fruits, harvested in two consecutive seasons at green, cherry and black stages, were used to study compositional changes in the cell walls during ripening. Ripening‐related changes in both harvests were characterised mainly by an increase in the solubilisation of pectic and hemicellulosic polysaccharides, an increase in the relative amount of arabinose in pectic polysaccharides and a decrease in the degree of methylesterification of pectic polysaccharides. Further to degrading processes, the data obtained suggest the synthesis of new polysaccharides. The analysis of olive cell wall phenolics showed mainly the presence of p‐coumaric acid, which increased in one harvest, whereas in the other the values did not differ. The samples of the second harvest, although presenting green, cherry and black colours, had less distinct ripening characteristics than those of the previous harvest. Different activity levels of polyphenol oxidase, polygalacturonase and pectin methylesterase might have contributed to the differences observed between the two harvests. The results showed the distinct extension of ripening‐related changes in the cell walls of the two harvests, indicating that the olive colour, although characteristic of the stage of ripening, cannot be strictly used for its evaluation and definition. Copyright © 2006 Society of Chemical Industry     

碱不溶性酵母胞壁多糖苯酚-硫酸测定法的研究

为了测定碱不溶性酵母胞壁多糖含量,采用硫酸溶液水解碱不溶性酵母胞壁多糖,苯酚-硫酸法测定水解液的糖含量。通过单因素和正交实验对硫酸溶液水解碱不溶性酵母胞壁多糖的条件进行了优化,优化后的水解条件为:称取碱不溶性酵母胞壁多糖10mg,加入3mol/L H2SO4溶液20m L置于100℃水浴中水解90min。水解液定容至250m L,测定其糖含量。该方法的精密度RSD为0.30%,稳定性RSD为0.67%,重现性RSD为0.29%,样品的平均加标回收率为99.87%,RSD为1.16%,是测定碱不溶性酵母胞壁多糖含量的有效方法。      

Effects of two contrasting dietary fibres on starch digestion,short‐chain fatty acid production and transit time in rats

Dietary fibres may cause dietary starch to escape digestion in the small intestine and enter the large intestine. If this results from the dietary fibres reducing the gastrointestinal transit time, those dietary fibres that reduce this the most would be expected to cause the most starch to escape digestion. We tested in rats the relative abilities of two contrasting dietary fibres, apple pectin (a soluble dietary fibre) and wheat straw (an insoluble, lignified dietary fibre), to reduce the whole gut transit time and to cause dietary starch to escape digestion. We provided male Wistar rats with a control, modified AIN‐76™ diet containing 20% fat but no dietary fibre, and with this diet containing 10% dietary fibre; the dietary fibre replaced the equivalent weight of starch in the control diet. Both dietary fibres, but particularly wheat straw, reduced the transit time compared with the fibre‐free control diet. Pectin, but not wheat straw, resulted in substantial amounts of starch in the caecal contents. This effect may result from the pectin increasing the viscosity of the digesta or causing it to gel. Large amounts of short‐chain fatty acids were found only in the caeca of rats provided with pectin. © 2000 Society of Chemical Industry     

The role of polysaccharides on the stability of colloidal particles of beer

This study aimed at understanding the influence of beer colloidal composition and size on physical stability of the colloidal suspensions in beer before filtration. The percentages of retention during filtration indicate that colloidal particles consist principally of polysaccharides (97.04%) and smaller amounts of proteins (2.87%) and polyphenols (0.22). The viscosity of a colloidal dispersion can be modelled as the sum of a hard‐sphere contribution and a colloidal force contribution. The colloidal force contribution is determined from the volume fraction of particles, the viscosity colloidal dispersion and the beer viscosity without particles. The volume fraction of particles could be estimated from the particle density and the total solid present in the beer. The fitting parameters of the correlation between the particles volume fraction and the colloidal force viscosity could explain the low stability of the colloidal particles of beer. This last determination is more specific than the simple viscosity of beer and could help to improve the prediction of the filtration flow.