碱法前处理对小麦麸皮酶解制取低聚木糖的影响

以小麦麸皮为原料,用不同浓度NaOH溶液进行预处理后结合微波消解制取低聚木糖。小麦麸皮以料液比1:10,经NaOH浓度2.5%,温度60℃,时间为2.5小时前处理及微波处理后酶解24h的样品中,低聚木糖提取率高到达22.79%.     

基于正交实验法优化从栀子黄色素中制备藏红花酸的工艺

基于正交实验法,优化从栀子黄色素中提取制备藏红花酸的碱水解工艺,以期可以简单高效地获得高纯度藏红花酸。建立高效液相色谱法(HPLC)测定藏红花酸含量,以藏红花酸的含量和得率为考察指标,采用正交实验法考察碱水解工艺中的料液比、NaOH浓度、水解温度和水解时间对产品中藏红花酸含量和得率的影响。确定栀子黄色素碱水解的最佳条件:料液比1∶6 g/mL、NaOH浓度3 mol/L、水解温度55℃、水解时间60 min。在该条件下制备获得的藏红花酸得率可达15.33%±1.25%;含量可达到97.24%±0.78%。优化后方法步骤简单易行,绿色无污染,一步制得高纯度藏红花酸,适用于工业化生产。     

花椒籽黑色素提取和脱蛋白技术研究

采用二次回归正交旋转组合试验优化了花椒籽黑色素的浸提工艺,并用蛋白酶酶解-Sevag法联用脱除花椒籽黑色素中的蛋白.结果表明:影响花椒籽黑色素提取效果的因素依次为温度>NaOH浓度>料液比,花椒籽黑色素提取的优化工艺参数为NaOH浓度为1.20 mol/L,料液比为1∶24.64,温度为70℃下提取2 h,共2次,所得花椒籽色素粗品为棕黑色无定型粉末,得率为6.1%,色价为201.62,蛋白质含量为44.83%~48.63%.碱性蛋白酶脱蛋白条件为温度50℃,pH 9,加酶量为粗色素溶液(浓度为1 mg/mL)体积的6%,再用Sevag法处理3次,蛋白质脱除率可达81.23%,花椒籽黑色素色价可提高1.5倍.     

正交实验法优化碱水解栀子提取物制取京尼平苷酸的工艺

以栀子提取物为原料,利用正交实验设计方法优化其碱水解制取京尼平苷酸的工艺。以京尼平苷酸产率为评价指标,考察了水解温度、NaOH加入量、料液比和水解时间4个单因素,采用四因素三水平正交实验设计优选得出最佳水解工艺:水解温度为70℃、NaOH加入量为14.0 m L、料液比1∶30 g/m L、水解时间为10 min,京尼平苷酸产率为11.53%。水解后溶液经过一次活性炭静态吸附和解吸,京尼平苷酸的含量可达45.33%。     

西兰花叶叶绿素提取及叶绿素铜钠盐制备工艺研究

研究了以西兰花叶为原料提取叶绿素制备叶绿素铜钠盐的工艺条件。通过正交试验对西兰花叶叶绿素提取工艺进行了优化,结果表明西兰花叶叶绿素提取的最佳条件为:乙醇浓度95%;料液比1∶6;萃取温度为70℃;萃取时间2 h;叶绿素铜钠盐制备条件为:5%NaOH,65℃皂化30 min;1%硫酸调pH 2.0,65℃酸化30 min;15%硫酸铜,65℃铜代反应60 min,成盐NaOH调pH 12,65℃1 h。     

锈毛莓总黄酮的提取工艺优化

采用乙醇回流提取法,对提取温度、乙醇浓度、时间、料液比进行单因素考察,结合正交试验,确定锈毛莓总黄酮最佳提取工艺。结果显示,最佳提取工艺为料液比1∶25、乙醇浓度60%、提取温度70 ℃、提取时间2.5 h,提取2次,总黄酮得率可达6.78%。     

响应面法优化黑水虻幼虫蛋白质提取工艺

【目的】对黑水虻Hermetia illucens幼虫蛋白质进行不同提取方法的比较,选择最优提取方法,并确定其最优工艺参数,为黑水虻幼虫蛋白提取与资源利用提供依据。【方法】以黑水虻幼虫为原料,分别采用碱提法、酶提法、盐提法和Tris-HCl缓冲液提法对黑水虻幼虫蛋白质进行提取,并比较分析。通过单因素试验分别确定NaOH质量浓度、液料比、提取温度及提取时间4个因素的较优水平。在单因素试验结果基础上,按照Box-Behnken响应面试验设计进行响应面优化试验。【结果】提取黑水虻幼虫蛋白质的4种方法中碱提法的提取率最高,最佳提取条件为：NaOH质量浓度2.44 g/100mL,液料比22 mL/g,提取温度53℃,提取时间2 h。提取率验证试验结果为88.49%,与预测值相对误差为0.28%。【结论】响应面模型拟合度高,优化出的最佳提取工艺可行。     

生物法合成β-丙氨酸的分离纯化工艺研究

依据天冬氨酸和β-丙氨酸等电点的差异,采用静态吸附和动态吸附法,筛选适于分离β-丙氨酸的最佳树脂,并研究最佳树脂的吸附动力学和料液pH值、上样液流速,洗脱剂浓度等对β-丙氨酸分离的影响。结果表明:β-丙氨酸吸附的最佳树脂为HZ014,HZ014的静态吸附70 min达到动态平衡,吸附容量为72.92 g.kg-1,吸附率高于90%,最佳料液流速是2 ml.min-1,料液最佳pH为5.0,洗脱剂氨水浓度为4%。     

中国温带旱柳物候期对气候变化的时空响应

为了揭示中国温带植物物候随时间变化和植物物候对气候变化响应的空间格局及其生态机制,利用52个站点1986—2005年的旱柳展叶始期、开花始期、果实成熟期、叶变色始期和落叶末期的物候数据,分析其时间序列的线性趋势,并通过建立基于最佳期间日均温的物候时间模型,确定物候发生日期对气温年际变化的响应。在研究的时段内,区域平均旱柳展叶始期、开花始期和果实成熟期的发生日期分别以-4.2 d/10 a、-3.8 d/10 a和-3.3 d/10 a的平均速率显著提前,而区域平均旱柳叶变色始期和落叶末期的发生日期则分别呈不显著推迟和以2.4 d/10 a的平均速率显著推迟的趋势。单站展叶始期、开花始期和果实成熟期发生日期的线性趋势以提前为主,显著提前的站点分别占40%、41%和29%;叶变色始期发生日期呈显著提前和显著推迟趋势的站点数相当,分别占17%和19%;落叶末期发生日期的线性趋势以推迟为主,显著推迟的站点占23%。各站展叶始期、开花始期和果实成熟期发生日期的线性趋势空间序列与相应的最佳期间日均温的线性趋势空间序列之间呈显著负相关,表明一个站点前期气温升高的速率越快,该站这些物候期发生日期提前的速率就越快。在物候期对气温年际变化的响应方面,区域平均春季最佳期间日均温每升高1℃,展叶始期、开花始期和果实成熟期的发生日期分别提前3.08 d、2.83 d和3.54 d;区域平均秋季最佳期间日均温每升高1℃,叶变色始期和落叶末期的发生日期分别推迟1.69 d和2.28 d。单站展叶始期和落叶末期发生日期对气温年际变化的响应表现出在温暖地区的站点比在寒冷地区的站点更为敏感的特点。总体上看,基于日均温的物候时间模型对春、夏季物候期的模拟精度明显高于对秋季物候期的模拟精度。建立了基于最佳期间日均温和日累积降水量的改进秋季物候模型,该模型使旱柳叶变色始期和落叶末期的模拟精度显著提高。由此可见,旱柳叶变色始期和落叶末期的发生日期受到前期气温和降水量的综合影响。     

枇杷叶中黄酮类化合物提取工艺研究

以枇杷叶为原料,对黄酮类化合物的提取工艺进行研究,考察乙醇浓度、提取温度、提取时间、料液比对枇杷叶中黄酮类化合物提取率的影响,并采用正交实验进行优化。结果表明四种因素对枇杷叶中黄酮类化合物提取率影响的大小顺序为:乙醇浓度>提取时间>提取温度>料液比,枇杷叶中黄酮类化合物提取的最佳工艺条件为提取时间30min、提取温度80℃、乙醇浓度40%、料液比1:20(g/mL),最佳条件下黄酮类化合物提取率为6.92%。     

Cross-linking of wheat gluten proteins during production of hard pretzels

The impact of the hot alkaline dip, prior to pretzel-baking, on the types and levels of cross-links between wheat proteins was studied. Protein extractability of pretzel dough in sodium dodecyl sulfate containing buffer decreased during alkaline dipping [45?s, 1.0% (w/v) NaOH, 90°C], and even more during baking (3?min at 250°C) and drying (10?min at 135°C). Reducing agent increased the extractability partly, indicating that both reducible (disulfide, SS) and non-reducible (non-SS) protein cross-links had been formed. The decrease in cystine levels suggested β-elimination of cystine releasing Cys and dehydroalanine (DHA). Subsequent reaction of DHA with Lys and Cys, induced the unusual and potentially cross-linking amino acids lysinoalanine (LAL) and lanthionine (LAN), respectively, in alkaline dipped dough (7?μmol LAN/g protein) and in the end product (9?μmol LAL and 50?μmol LAN/g protein). The baking/drying step increased sample redness, decreased Lys levels more than expected based on LAL formation (57?μmol/g protein), and induced a loss of reducing sugars (99?μmol/g protein), which suggested the potential contribution of Maillard-derived cross-links to the observed extractability loss. However, levels of Maillard products which possibly cross-link proteins, are small compared to DHA-derived cross-links. Higher dipping temperatures, longer dipping times, and higher NaOH concentrations increased protein extractability losses and redness, as well as LAL and LAN levels in the end product. No indications for Maillard-derived cross-links or LAL in pretzel dough immediately after dipping were found, even when severe dipping conditions were used.     

Detection of latent infections caused by Colletotrichum sp. in olive fruit

Aims

To set up a practical method to detect latent infections of Colletotrichum sp., the causal agent of olive anthracnose, on olives before the onset of disease symptoms.

Methods and Results

Freezing, sodium hydroxide (NaOH), ethanol and ethylene treatments were evaluated to detect latent infections on inoculated and naturally infected olive fruit by Colletotrichum sp. as non‐hazardous alternatives to paraquat. Treatments were conducted using fruit of cultivars Arbequina and Hojiblanca. The disease incidence and T₅₀ were calculated. Dipping in NaOH 0·05% solution and the paraquat method were the most effective treatments on both inoculated and naturally infected fruit, although the value of T₅₀ was lower for the NaOH method than for the paraquat method in one of the experiments. Subsequently, the dipping time in NaOH 0·05% was evaluated. Longer dipping times in NaOH 0·05% were better than shorter ones in cultivar Arbequina, with 72 h being the most effective in cultivar Hojiblanca.

Conclusions

NaOH solution is a practical method to detect latent infections of Colletotrichum sp. on immature olive fruit.

Significance and Impact of the Study

This study is relevant because we set up a viable, non‐hazardous alternative to paraquat to detect latent infections of Colletotrichum sp. using NaOH. The use of NaOH is a simple and eco‐friendly tool that allows the determination of the level of latent infections by Colletotrichum in olives. Therefore, our method will be useful in decision‐making processes for disease management before the appearance of the first visible symptoms.     

Subcutaneous terbutaline and control of brittle asthma or appreciable morning dipping.

In a pilot study two patients with brittle asthma and two with morning dipping received terbutaline or a placebo administered subcutaneously either by continuous infusion or in injections every six hours. In two patients brittle asthma was completely suppressed by terbutaline 1 mg/day given by either method. In the two others early morning dipping responded only to continuous subcutaneous infusions of terbutaline 12 mg/day. Terbutaline administered subcutaneously may be an effective treatment in asthmatic patients who show important diurnal variations in air flow.     

Kinetics of cellulose regeneration from cellulose--NaOH--water gels and comparison with cellulose--N-methylmorpholine-N-oxide--water solutions

The regeneration kinetics of cellulose from cellulose--NaOH--water gels immersed in a nonsolvent bath is studied in detail. Cellulose concentration, bath type, and temperature were varied, and diffusion coefficients were determined. The results were compared with data measured and taken from the literature on the regeneration kinetics of cellulose from cellulose--N-methylmorpholine-N-oxide (NMMO) monohydrate solutions. Different theories developed for the transport behavior of solutes in hydrogels or in porous media were tested on the systems studied. While the diffusion of NaOH from cellulose--NaOH--water gels into water has to be described with "porous media" approaches, the interpretation of NMMO diffusion is complicated because of the change of NMMO's state during regeneration (from solid crystalline to liquid) and the high concentration of NMMO in the sample. The activation energies were calculated from diffusion coefficient dependence on temperature for both systems and compared with the ones obtained from the rheological measurements. The activation energy of cellulose--NaOH--water systems does not depend on cellulose concentration or the way of measurement. This result shows that whatever the system is, pure NaOH--water solution, cellulose--NaOH--water solution, or cellulose--NaOH--water gel, it is NaOH hydrate with or without cellulose in solution, which is moving in the system. The swelling of cellulose in different nonsolvent liquids such as water or different alcohols during regeneration was investigated and interpreted using the Hildebrand parameter.     

Mucous solids and liquid secretion by airways: studies with normal pig, cystic fibrosis human, and non-cystic fibrosis human bronchi

To better understand how airways produce thick airway mucus, nonvolatile solids were measured in liquid secreted by bronchi from normal pig, cystic fibrosis (CF) human, and non-CF human lungs. Bronchi were exposed to various secretagogues and anion secretion inhibitors to induce a range of liquid volume secretion rates. In all three groups, the relationship of solids concentration (percent nonvolatile solids) to liquid volume secretion rate was curvilinear, with higher solids concentration associated with lower rates of liquid volume secretion. In contrast, the secretion rates of solids mass and water mass as functions of liquid volume secretion rates exhibited positive linear correlations. The y-intercepts of the solids mass-liquid volume secretion relationships for all three groups were positive, thus accounting for the higher solids concentrations in airway liquid at low rates of secretion. Predictive models derived from the solids mass and water mass linear equations fit the experimental percent solids data for the three groups. The ratio of solids mass secretion to liquid volume secretion was 5.2 and 2.4 times higher for CF bronchi than for pig and non-CF bronchi, respectively. These results indicate that normal pig, non-CF human, and CF human bronchi produce a high-percent-solids mucus (>8%) at low rates of liquid volume secretion (≤1.0 μl·cm(-2)·h(-1)). However, CF bronchi produce mucus with twice the percent solids (~8%) of pig or non-CF human bronchi at liquid volume secretion rates ≥4.0 μl·cm(-2)·h(-1).     

矿物油乳剂对烟蚜茧蜂的安全性评价

【目的】矿物油乳剂因其安全性好、杀虫谱广、不易产生抗性等优点,被广泛用于果蔬、农作物、园林害虫的防治,但有关其对害虫天敌烟蚜茧蜂的安全性尚不明确。因此,本文研究矿物油乳剂对烟蚜茧蜂不同发育阶段的安全性,为更好地协调蚜虫的化学防治和生物防治提供理论依据。【方法】在实验室条件下采用药膜法和浸渍法测定了不同浓度(150、250、350、450倍液)矿物油乳剂对烟蚜茧蜂各发育阶段的影响。【结果】矿物油乳剂对烟蚜茧蜂成虫的影响较小,无明显胃毒作用,但有一定的触杀作用,以最高浓度150倍液(4986.960 mg·L-1)处理24 h后的存活率依然高达92%;矿物油乳剂对烟蚜茧蜂寄生蚜有较高的致死率,LC50为859.541 mg·L-1,该浓度远远低于此次供试的最低浓度450倍液(1662.320 mg·L-1),说明矿物油乳剂对烟蚜茧蜂卵和幼虫的安全性较差;矿物油乳剂对烟蚜茧蜂蛹期羽化率的影响较显著,处理组的僵蚜与对照组的僵蚜相比,羽化高峰期均滞后1 d,且羽化率随着处理浓度的增大而下降(450倍液时羽化率为81.25%,150倍液时仅为47.75%)。【结论】当蚜虫发生严重时,可考虑在烟蚜茧蜂成虫期协调使用矿物油乳剂进行联合控制,但矿物油乳剂的使用浓度和施用时间还有待进一步确定。     

Direct measurement of superoxide anion produced in biological systems by ESR spectrometry: a pH-jump method

For direct measurement of the ESR signal of superoxide anion (O2-) produced in biological samples, O2- generated at a physiological pH was trapped in alkaline media instead of by a rapid freezing method, and then its signal was measured by ESR spectroscopy at 77 K. A reaction mixture for O2- generation, such as xanthine oxidase-xanthine and neutrophils, was incubated at a physiological pH (pH 7.0-7.5) for a suitable reaction period (30s), then an aliquot (300 microliters) was pipetted out and squirted into 600 microliters of 0.5 M NaOH to stabilize O2- (pH-jump). The alkaline mixture was promptly introduced into an ESR tube and frozen by dipping the tube directly into a cooling liquid. A typical signal of O2- was detected by ESR spectroscopy and the amount of trapped O2- was measured quantitatively at 77 K. The back reaction of O2- generation from H2O2 was negligible in 0.5 M NaOH. To avoid any artificial spectrum due to autoxidation of biological samples by the pH-jump procedure, the background spectrum should be subtracted from the obtained spectrum. This pH-jump method should be widely available for direct demonstration of O2- production in biological systems at physiological pH, because an advantage of this method is the simple operation for trapping O2- without the use of any rapid-mixing apparatus as compared with the rapid freezing method.     

Supplementation of alkali-treated rice straw

Goats were fed rice straw treated with 0,4 or 8% NaOH, dehydrated palm oil mill effluent (POME) at 20 or 30 g/kg liveweight (LW)/day and Leucaena at 5 or 10 g dry matter (DM)/kg LW/day in Experiment 1, and rice straw treated with 4% NaOH or 4% NH₄OH, POME at 30 g/kg LW/day and either Napier grass or Leucaena at 10 g DM/kg LW/day in Experiment 2. Treatment with 4% NaOH promoted the highest intake of rice straw. 10·3 and 12·4 g DM/kg LW/day respectively in Experiments 1 and 2. Feeding Leucaena at 10 g DM/kg LW/day significantly increased total intake (36·0 g DM/kg LW/day) and DM digestibility (59·0%) in Experiment 1, and supported a LW gain of 63 g/day in Experiment 2. It is concluded that diets comprising 25% NaOH-straw, 50% POME and 25% Leucaena permitted dietary nutrients to be used efficiently and maximised the inclusion of by-products.     

A unique anther-mucilage in the pollination biology of Tylosema esculentum

Summary Tylosema esculentum, a perennial geophyte bearing yellow distylous flowers in racemes, maintains a high degree of outbreeding through reciprocal herkogamy. In addition, a viscous liquid, the anther-mucilage, is produced by the anther connective tissue and released concurrently with the pollen. The polysaccharide- and lipid-rich mucilage, which is functional in the shedding and transfer of pollen, is available for more than 1 day due to the gradual solidification of the mucilage. The assimilation of the pollen with the liquid substance significantly affects the pollination biology of T. esculentum. This is the first report on the unique phenomenon of wet pollen in the Caesalpiniaceae.