膜技术在提取甜菊糖中的应用

应用膜分离技术对传统工艺进行改进.首先用微滤膜和超滤膜两级膜对甜菊糖水提液进行除杂,除掉果胶等大分子杂质、色素和水溶性蛋白等杂质,最后用纳滤膜进行脱盐浓缩.结果表明,进过膜处理后的液体浓缩了15倍,纯度达到87％左右.     

采用微滤膜浓缩乳酸菌发酵液的工艺条件研究

采用先进的微滤膜技术浓缩乳酸菌发酵液 ,结果表明 ,调整总通量、跨膜压力可以减少膜浓差极化及膜污染 ;对微滤膜的超微结构、菌体状态、杂质吸附进行扫描电镜观察 ,发现微滤膜孔径大小不一 ,呈现宽窄不同的谱图 ;微滤膜孔径分布的均一性也与膜的质量有关 ;德氏乳杆菌保加利亚亚种、唾液链球菌嗜热亚种等发酵菌液在微滤膜中均可以得到有效截留。颗粒及吸附的菌体会形成膜的覆盖层。微滤浓缩、超滤浓缩、离心浓缩的浓缩比分别为 1 9 1、1 6 9、1 5 9倍 ,浓缩后的菌液浓度分别为 1 1 5× 1 0 10 cfu/mL、9 79× 1 0 9cfu/mL、5 3 8× 1 0 9cfu/mL。     

纳滤浓缩古龙酸提取液的研究

纳滤膜能在常温下将超滤提取后的古龙酸提取液浓缩,替代了原有的蒸发浓缩。既降低了能耗,又防止了料液被高温分解破坏,提高了产品的收率和成品质量,经济效益可观。现纳滤膜已成功地运用到维生素C大生产中。污染后的膜用加酶复合型清洗剂进行清洗,其效果优于单一型酸、碱清洗剂。     

纳滤膜技术及其在食品业的应用

综述了纳滤膜的分离机理及其在食品行业中的应用研究现状。介绍了纳滤膜在多糖分离和精制、果汁的高浓度浓缩、氨基酸的分离、牛奶及乳清蛋白的浓缩以及纳滤膜生化反应器的开发等方面的应用     

卤鸡腿预煮废弃液纳滤浓缩工艺的研究

利用纳滤膜技术浓缩鸡肉卤制过程中产生的废弃液,以代替传统的多效浓缩方法,并对纳滤的工艺条件进行了优化研究.实验表明:当选用孔径360 Da的纳滤膜,操作压力为1.5 MPa,操作温度为40℃,pH为6.0,浓缩效果最好;纳滤浓缩30 min后,膜通量趋于平稳.将卤制加工废弃液经过膜分离浓缩制成天然调味品,一方面可开发新型风味的调味品,另一方面对于环境保护,实现清洁生产具有重大意义.     

膜技术在制备棉籽蛋白多肽中的应用研究

采用微滤膜对棉籽蛋白酶解液进行除杂,首先根据膜通量及蛋白透过率选定合适的微滤膜,再考察了操作压力和温度对选定微滤膜通量的影响。结果表明:膜孔径为100nm的微滤膜较30nm微滤膜更适合本物料体系。且随着分离时间的延长,膜通量逐渐减小,至20min~30min后,膜通量趋于稳定;膜通量与压力和温度在一定范围内呈正相关。     

甲壳素碱煮废水耐碱纳滤膜纳滤传质机理研究

目的:使用耐碱纳滤膜(NFM)处理甲壳素碱煮液回收有机氮,探究不同操作条件对膜通量及目标物截留率的影响,确定膜主要操作参数,并进行纳滤(NF)浓缩传质机理分析。方法:在不同跨膜压差(TMP)及温度条件下分别对等体积的同一物料进行8h的全循环,并通过截留率及膜通量来确定最佳TMP和进料温度。在最佳膜操作条件下对物料进行纳滤浓缩回收肽。基于固定电荷TMS模型和立体位阻SHP模型,通过Matlab拟合膜相关参数,离线分析纳滤浓缩中间过程传质变化。结果:在TMP30bar,进料温度40℃条件下进行纳滤浓缩,可有效回收有机氮。物料衡算结果表明蛋白总透过率仅5.92%。在该操作条件下,纳滤浓缩过程中总氮截留率呈增长趋势。结论:使用耐酸碱纳滤膜可以有效回收有机氮。使用TMS和SHP模型,通过Matlab软件拟合膜参数,纳滤浓缩过程中膜孔会发生微弱的阻塞,且有效膜层吸附层的表面电荷密度较原始膜电荷密度大。在Donnan效应作用下,总氮的截留率呈增长趋势。     

芦荟水提液的除杂浓缩

采用膜分离技术对芦荟水提液进行除杂、浓缩,以提高芦荟多糖的纯度.试验比较了微滤膜10K和微滤膜20K的除杂效果,选用更合适的微滤膜20K:可使芦荟多糖透过率高达97.6%、杂质截留率达17.8%;比较了纳滤膜MWC和纳滤膜GMC的浓缩效果,选用更合适的纳滤膜MWC:芦荟多糖截留率高达98.3%,浓缩液芦荟多糖的纯度达73.6%.     

纳滤膜浓缩混合油过程中的操作条件研究

为解决传统的混合油浓缩过程中溶剂回收能耗高的问题,本文分别采用3种不同截留分子量的纳滤膜进行溶剂回收,并考察了操作压力、料液浓度等条件对分离性能的影响。在0.3MPa下,料液浓度在20%左右,采用NF-400膜,大豆油的截留率在20%以上,膜的渗透通量为0.33L/（m~2·h）。     

膜技术在色氨酸提取工艺的应用

介绍了膜技术在色氨酸料液提取工艺中的应用，通过微滤膜过滤进行澄清色氨酸发酵料液；通过脱色膜脱色，使色氨酸料液的透光度由2％--6％提高至38％以上；通过浓缩膜浓缩，色氨酸浓度可达到35．5g／L以上。膜技术应用于色氨酸提取工艺中，提取收率可提高至85％-95％，能耗降至传统工艺的一半。     

Malted and unmalted oats in brewing

Using oats as a raw material in brewing has recently become the focus of increased interest. This is due to research findings that have shown that oats can be consumed safely by coeliac sufferers. It is also a response to consumer demand for products with novel sensory properties. In this study, beer was produced entirely from oat malt, from barley malt and from oat and barley malts mixed with various quantities of unmalted oats. Compared with barley wort, wort made from malted oats provided a lower extract content and had a higher protein content, but a lower free amino nitrogen content (FAN). The oat wort also showed increased viscosity and haze. The addition of unmalted oats during wort production produced significant changes in the physico‐chemical parameters of both oat and barley worts and beers. Unmalted oats caused an increase in wort viscosity and haze, and a reduction in total soluble nitrogen and FAN. Unmalted oats also contributed to lowering the concentration of higher alcohols and esters. Beer made from 100% oat and barley malts exhibited a similar alcohol content. The use of an oat adjunct in both cases resulted in a lower ethanol content. The introduction of enzyme preparations during the production of wort with oat adjunct had many benefits: increased extract content and FAN; a higher volume of wort; and a lower viscosity that led to faster wort filtration. This research suggests that the use of enzymes is necessary to make production using a high proportion of oats in the grist profitable. Copyright © 2014 The Institute of Brewing & Distilling     

Inhibition of Fusarium graminearum growth in flour gel cultures by hexane-soluble compounds from oat (Avena sativa L.) flour

Fusarium head blight, incited by the fungus Fusarium graminearum, primarily affects wheat (Triticum aestivum) and barley (Hordeum vulgarum), while oat (Avena sativa) appears to be more resistant. Although this has generally been attributed to the open panicle of oats, we hypothesized that a chemical component of oats might contribute to this resistance. To test this hypothesis, we created culture media made of wheat, barley, and oat flour gels (6 g of flour in 20 ml of water, gelled by autoclaving) and inoculated these with plugs of F. graminearum from actively growing cultures. Fusarium growth was measured from the diameter of the fungal plaque. Plaque diameter was significantly smaller on oat flour cultures than on wheat or barley cultures after 40 to 80 h of growth. Ergosterol concentration was also significantly lower in oat cultures than in wheat cultures after growth. A hexane extract from oats added to wheat flour also inhibited Fusarium growth, and Fusarium grew better on hexane-defatted oat flour. The growth of Fusarium on oat flour was significantly and negatively affected by the oil concentration in the oat, in a linear relationship. A hexane-soluble chemical in oat flour appears to inhibit Fusarium growth and might contribute to oat's resistance to Fusarium head blight. Oxygenated fatty acids, including hydroxy, dihydroxy, and epoxy fatty acids, were identified in the hexane extracts and are likely candidates for causing the inhibition.     

Survey of T-2 and HT-2 toxins by LC–MS/MS in oats and oat products from European oat mills in 2005–2009

T-2 and HT-2 toxins were analysed in oats (n?=?243), oat flakes (n?=?529), oat meal (n?=?105) and oat by-products (n?=?209) from 11 European mills during 2005–2009 by high-performance liquid chromatography with a triple quadrupole mass spectrometer. Limits of quantification were 5?µg?kg^?1 for both T-2 and HT-2 toxins in oats. The incidence of T-2?+?HT-2 (>5?µg?kg^?1) in oats, oat flakes, oat meal and oat by-products was 93, 77, 34 and 99%, respectively. The mean values of T-2?+?HT-2 were 94, 17, 11 and 293?µg?kg^?1 for oats, oat flakes, oat meal and oat by-products, respectively. T-2 and HT-2 occurred together and the T-2 level was 52% of HT-2 in oats. Maximal T-2 and HT-2 concentration in oat flakes and oat meal were 197 and 118?µg?kg^?1. The toxins were reduced by 82–88% during processing, but increased 3.1 times in oat by-products.     

Replacement of barley with oats and dehulled oats: Effects on milk production,enteric methane emissions,and energy utilization in dairy cows fed a grass silage-based diet

Sixteen Nordic Red dairy cows, at 80 ± 4.6 d in milk and with an average body weight of 624 ± 91.8 kg, were used in a replicated 4 × 4 Latin square design to investigate the effects of different concentrate supplements on milk production, enteric CH₄ emissions, ruminal fermentation, digestibility, and energy utilization. The cows were blocked into 4 groups based on parity and milk yield and randomly assigned to 1 of 4 experimental concentrates: (1) barley, (2) hulled oats, (3) an oat mixture consisting of hulled and dehulled oats, 50:50 on dry matter basis, and (4) dehulled oats; canola meal was a protein supplement in all 4 concentrates. The cows were fed grass silage and experimental concentrate (forage-to-concentrate ratio 60:40 on dry matter basis) ad libitum. To compare the effects of barley and oats, the barley diet was compared with the overall mean of the hulled oat, oat mixture, and dehulled oat diets. To investigate the effects of gradual replacement of hulled oats with dehulled oats, linear and quadratic contrasts were specified. Milk and energy-corrected milk (ECM) yield were higher on the oat diets compared with the barley diet but were not affected by the type of oats. Concentrations of milk constituents were not affected by grain species or type of oats, except for protein concentration, which was lower on the oat diets than on the barley diet. Feeding the oat diets led to higher milk protein yield and higher milk urea N concentrations. Feed efficiency tended to be higher on the oat diets, and linearly increased with increased inclusion of dehulled oats. Methane emissions (g/d) and CH₄ yield (g/kg of dry matter intake) were unaffected by grain species but increased linearly with increasing inclusion of dehulled oats in the diet. Because of higher ECM yield, CH₄ intensity (g/kg of ECM) was on average 5.7% lower from cows on the oat diets than on the barley diet. Ruminal fermentation was not affected by dietary treatment. Total-tract apparent digestibility of organic matter, crude protein, and neutral detergent fiber was unaffected by grain species but linearly increased with increasing inclusion of dehulled oats. Gross energy content was higher on the oat diets and linearly increased with increasing inclusion of dehulled oats. Feeding the oat diets led to a lower ratio of CH₄ energy to gross energy intake, greater milk energy and heat production but no change in energy balance. Gradual replacement of hulled oats with dehulled oats linearly increased gross energy digestibility, CH₄ energy, metabolizable energy intake, heat production, and energy balance. We observed no effect of dietary treatment on efficiency of metabolizable energy use for lactation. In conclusion, replacing barley with any type of oats increased milk and ECM yield, which led to a 5.7% decrease in CH₄ intensity. In addition, dehulling of oats before feeding is unnecessary because it did not significantly improve production performance of dairy cows in positive energy balance.     

A comparative study of oat (Avena sativa) cultivars as brewing adjuncts

Brewing with high levels of unmalted oats (Avena sativa) has proven to be successful despite their high contents of β-glucan, protein, and fat. However, little is known about the effect of different oat cultivars on the quality and processability of mashes and worts. Therefore, the aim of this study was to compare the mashing performance of eight oat cultivars, selected because of their low contents of β-glucan, protein, fat, and/or high starch content, when substituting 20 or 40 % barley malt. For this purpose, seven husked (A. sativa L. ‘Lutz’, ‘Buggy’, ‘Galaxy’, ‘Scorpion’, ‘Typhon’, ‘Ivory’, ‘Curly’) and one naked oat cultivar (A. sativa var. nuda ‘NORD 07/711’) were fully characterized using standard methods, Lab-on-a-Chip capillary electrophoresis, and scanning electron microscopy. The rheological behavior of mashes containing up to 40 % of each oat cultivar was measured during mashing by applying a Physica MCR rheometer. In addition, the quality of worts obtained from laboratory-scale mashing trials was analyzed particularly with regard to their cytolytic, proteolytic, and amylolytic properties. The substitution of up to 40 % barley malt with husked or naked oats resulted in significantly higher pH values, β-glucan contents, and viscosities as well as significantly lower soluble nitrogen and polyphenol contents, color values, filtration rates, and apparent attenuation limits. Naked oats contained significantly less β-glucan as well as more protein and starch than the seven husked oat cultivars. The replacement of barley malt with naked oats resulted in a constant extract yield, whereas the use of husked oats caused significant extract losses.     

Optimization and Validation of a Fluorescence Polarization Immunoassay for Rapid Detection of T-2 and HT-2 Toxins in Cereals and Cereal-Based Products

A fluorescence polarization (FP) immunoassay has been optimized and validated for rapid quantification of T-2 and HT-2 toxins in both unprocessed cereals, including oats, barley and rye, and cereal-based products for direct human consumption, such as oat flakes, oats crispbread and pasta. Samples were extracted with 90 % methanol, and the extract was filtered and diluted with water or sodium chloride solution prior to the FP immunoassay. Overall mean recoveries from spiked oats, rye, barley, oat flakes, oats crispbread and pasta ranged from 101 to 107 %, with relative standard deviations lower than 7 %. Limits of detection (LODs) of the FP immunoassay were 70 μg/kg for oats, 40 μg/kg for oat flakes and barley, 25 μg/kg for pasta and 20 μg/kg for rye and oats crispbread. The trueness of the immunoassay was assessed by using two oat and oat flake reference materials for T-2 and HT-2 toxins, showing good accuracy and precision. Good correlations (r?>?0.953) were observed between T-2 and HT-2 toxin contents in naturally and artificially contaminated samples determined by both FP immunoassay and ultra-high-performance liquid chromatography (UHPLC) with immunoaffinity column cleanup used as reference method. These results, combined with rapidity and simplicity of the assay, show that the optimized assay is suitable for high-throughput screening, as well as for reliable quantitative determination of T-2 and HT-2 toxins in cereals and cereal-based products.     

冠突散囊菌发酵燕麦对多酚含量影响的研究

以燕麦为原料,采用冠突散囊菌（Eurotium cristatum）发酵燕麦,探讨燕麦多酚的提取工艺以及发酵条件对多酚含量的影响。结果表明,多酚提取工艺条件为燕麦料液比1∶16（g∶mL）,乙醇体积分数60%,浸提温度45 ℃,浸提时间60 min。在此最佳提取工艺条件下,多酚含量可达1.48 mg/g。冠突散囊菌发酵燕麦的发酵条件为燕麦料液比1∶1.0（g∶mL）,接种量2%,28 ℃发酵4 d。在此最佳发酵条件及提取工艺条件下,多酚含量最高可达2.28 mg/g。经发酵后的燕麦多酚含量明显升高。     

Brewing with 100% Oat Malt

Oats are a cereal with beneficial nutritional properties and also unrealized brewing potential. Furthermore, oats can be tolerated by the majority of people who suffer from celiac disease. Malting of oats produced a malt, which was found suitable for brewing a 100% oat malt beer. The mashing regime, designed by using mathematical modelling, was successfully transferred to a pilot scale plant. The improved lautering performance of oat malt was due to its higher husk content, which also led to a lower extract content in oat wort when compared to barley wort. The protein profile of oat wort, as measured by using Lab‐on‐a‐Chip analysis, revealed that there was no significant difference in the protein profile between oat and barley wort. The fermentation of oat and barley worts followed the same trend; differences could only be seen in the higher pH and lower alcohol content of the oat beer. The flavour analysis of oat beer revealed some special characteristics such as a strong berry flavour and a lower amount of staling compounds when forced aged. This study revealed that it was possible to brew a 100% oat malt beer and that the produced beer was comparable to a barley malt beer.     

燕麦研究进展

燕麦,一般分为带稃型皮燕麦和裸粒型裸燕麦两大类,燕麦营养成分包括蛋白质、脂肪、淀粉、膳食纤维、抗氧化物、维生素和矿物质等,现代营养学和医学研究表明,燕麦含有多种活性营养成分,具有降血脂、降血糖、减肥和美容等多种功能。目前有关燕麦研究主要集中在燕麦β-葡聚糖、蛋白、油脂等方面;该文主要讲述燕麦主要成分及其一些应用。     

气相色谱结合主成分分析和聚类分析用于裸燕麦脂肪酸标准指纹图谱的建立

采用气相色谱(GC)技术结合主成分分析(PCA)对62个不同产地及不同品种的燕麦样品脂肪酸进行分析鉴定。以PCA得分散点图区分出14个皮燕麦样品。对其余48个裸燕麦样品通过聚类分析优选46个样品,采用共有模式法筛选出它们含有的11种共有特征峰,并构建裸燕麦脂肪酸标准指纹图谱。通过方法学考察,11种共有脂肪酸精密度、重复性和稳定性的RSD分别小于3.069%、4.249%和4.900%,符合指纹图谱的检测要求。相似度分析得出46个样品的相似度均大于0.99,表明所建立的标准指纹图谱具有高度的特征性、唯一性和准确性。本研究弥补了裸燕麦指纹图谱信息的空白,进一步完善了谷物脂肪酸数据库,为谷物营养性脂质体鉴别技术体系构建奠定了基础。