粗酶水解全脂豆粉提取油脂和蛋白

水酶法提取大豆油和蛋白是一项可替代溶剂浸提制油工艺的绿色环保技术,但是商品酶的价格较高且酶活易受外界环境影响,使水酶法制油技术的应用受到限制。该试验在优化过的培养基中接种枯草芽孢杆菌发酵培养42 h,所得发酵液经测定含有碱性和中性两种蛋白酶,所得粗酶经透析浓缩后,在碱性蛋白酶活为(2?000±200) U/mL,中性蛋白酶活为(1?500±200) U/mL时,在酶液中接入挤压膨化豆粉水解。通过对酶解条件的优化,试验证实在温度55℃,料液比1∶8 g/mL,起始pH值为10的条件下水解6 h,总油提取率有最大值,达到了94.2%,总蛋白提取率为90.1%,跟商品Alcalase碱性蛋白酶提取相比,总油提取率增加了1.9%,总蛋白提取率降低了2%。通过对粗酶和商品Alcalase酶水解豆粉过程产生的乳状液破乳后油的品质分析,发现二者所得油的性能指标没有明显区别,品质均优于浸提法制油,粗酶提取的水解蛋白比用Alcalase碱性蛋白酶水解的分子量更小,范围分布更广。     

碱法制备蚕蛹蛋白浸提条件的优化

该文通过中心组合设计及相应面分析.研究了碱法制各蚕蛹蛋白的浸提条件对蚕蛹蛋白浸提率的影响,得到了蚕蛹蛋白提取率的数学模型.优化了蚕蛹蛋白的浸提的条件,提高了碱法制备蚕蛹蚩白的蛋白提取率.结果表明NaOH浓度和液固比(V/m)对蛋蛹蛋白提取率影响显著(P<0.05).蚕蛹蛋白浸提的最佳工艺条件为:NaOH浓度1.03%、液固比(V/m)70:1、没提温度50℃、NaC1浓度0.070moVL.在此最佳工艺条件下蚕蛹蛋白的实际提取率达78.69%.利用优化工艺条件制备的桑蚕蛹蛋白,其蛋白含量为96.70%,必需氨基酸占总氨基酸含量的47.1%,必需氨基酸与非必需氨基酸的比值为0.9,具有较好的应用价值.     

碱法制备蚕蛹蛋白浸提条件的优化（简报）

该文通过中心组合设计及相应面分析,研究了碱法制备蚕蛹蛋白的浸提条件对蚕蛹蛋白浸提率的影响,得到了蚕蛹蛋白提取率的数学模型。优化了蚕蛹蛋白的浸提的条件,提高了碱法制备蚕蛹蛋白的蛋白提取率。结果表明NaOH浓度和液固比（V/m）对蚕蛹蛋白提取率影响显著（P＜0.05）。蚕蛹蛋白浸提的最佳工艺条件为：NaOH浓度1.03%、液固比（V/m）70︰1、浸提温度50℃、NaCl浓度0.070 mol/L。在此最佳工艺条件下蚕蛹蛋白的实际提取率达78.69%。利用优化工艺条件制备的桑蚕蛹蛋白,其蛋白含量为96.70%,必需氨基酸占总氨基酸含量的47.1%,必需氨基酸与非必需氨基酸的比值为0.9,具有较好的应用价值。     

冷榨菜籽蛋白的碱性电解水提取工艺及其结构性能表征

为探寻一种油料蛋白提取方法,该研究以双低冷榨菜籽饼为原料,碱性电解水为溶剂,通过单因素与响应面试验确定了碱性电解水提取冷榨菜籽饼分离蛋白（Alkaline electrolyzed water extracted Rapeseed Protein,ARP）的优化条件,并与相同条件下碱溶酸沉法提取菜籽分离蛋白（Ultrapure water extracted Rapeseed Protein,URP）的结果进行对比。结果表明: 提取工艺各环节因素对菜籽蛋白提取率影响的主次顺序分别为：碱性电解水pH值、温度、料液比、时间;提取优化工艺条件为温度45 ℃、碱性电解水pH值11.5、料液比1:10 g/mL和提取时间60 min,蛋白质提取率为59.34%。与相同条件下碱溶酸沉法相比,碱性电解水提取的菜籽分离蛋白游离巯基和二硫键含量高、表面疏水性强、粒径小、ζ电位绝对值大,同时其提取率、溶解性、持油性、乳化性和起泡性均显著得到改善（P＜0.05）;此外,ARP内源荧光光谱强度更高,二级结构更有序。由此可知,该研究结果为碱性电解水提取冷榨菜籽饼蛋白提供参考,不仅提高了提取率,而且最大程度地减少了对菜籽蛋白结构和功能特性的破坏。     

雷公藤提取农药用总生物碱工艺的优化(简报)

为杀虫活性物质雷公藤生物碱的产业化开发利用奠定基础,以雷公藤根皮中总生物碱提取率为评价指标,综合考察pH值、提取时间、乙醇浓度、固液比和提取次数5个关键因素的影响,以L16(45)正交试验设计优选了雷公藤总生物碱的提取工艺条件,并利用人工神经网络进行仿真、评估和优化,最终获得了雷公藤根皮中总生物碱的提取优化工艺:根皮粉细度30目,pH2.5,固液比1︰10,乙醇浓度65%,提取时间2h,提取2次。该优化工艺条件不仅可减少成本,降低能耗,而且使雷公藤总生物碱提取率略有提高,在实际生产中具有较好的应用价值。     

水酶法提取百香果籽油工艺优化研究

采用水酶法从百香果籽中提取百香果籽油.首先,采用单因素方法对复合酶添加量、酶解温度、酶解时间、料液比四个因素进行考查,在此基础上进行四因素三水平的正交试验优化.最佳工艺条件为:复合酶(中性蛋白酶:果胶酶:纤维素酶=2:1:1)添加量为4％,料液比1:3,酶解温度55℃,酶解时间5 h,此条件下百香果籽油的提取率为62....     

模糊评判优化水酶法提取膨化大豆油脂和蛋白

针对水酶法同时提取大豆油与蛋白时,两种目标对工艺参数的优化有差别,因此应用模糊综合评判法对工艺参数进行双目标综合优化,得到同时兼顾高油脂提取率与高蛋白提取率的酶解工艺参数。其结果为：加酶量1.85%,酶解温度50℃,酶解时间3.6 h,料液比1︰6,pH值为9。此时,油脂提取率为92.76%左右,蛋白提取率为93.81%左右。利用扫描电子显微镜、能谱分析以及显微切片分别就蛋白水解状态对油脂释放影响机理进行了研究。通过研究可知,挤压膨化再粉碎后的大豆粉水解过程中油脂的释放取决于蛋白水解状态,经过挤压膨化后大豆细胞结构已经被较充分破坏,而大豆油脂与蛋白的作用没有被完全破坏,所以需要把蛋白充分水解才能使油脂释放聚集,因此挤压膨化后水酶法可以兼顾得到高油脂提取率和高蛋白提取率。     

超声波辅助提取紫丁香叶叶绿素的工艺

以深秋的紫丁香树叶为原料,利用超声波辅助提取其中的叶绿素。首先研究了4种不同溶剂对提取的影响,然后在单因子试验基础上,探讨了料液比、超声波功率、超声波处理时间和超声提取次数4个因素对叶绿素提取的影响,用正交试验法优化了超声波辅助提取叶绿素的条件。最后将超声波法与传统提取法进行了对比。结果表明,紫丁香树叶中叶绿素a和叶绿素b的含量分别为0.37%和0.15%,叶绿素的总含量为0.52%;以乙醇∶丙酮为1∶2之混合溶剂的提取效果最好;优化的叶绿素超声波辅助提取条件为:料液比1∶7.5,超声波功率400W,提取3次,每次处理时间20min,提取率能达到(91.85±0.8)%。室温条件下,超声波辅助提取的提取率高于传统提取法17.13个百分点。     

菜籽蛋白的提取和纯化

为了对菜籽饼进行综合利用,以低温压榨制油的双低菜籽饼为原料,探讨了菜籽蛋白的提取和纯化工艺.通过料液pH值的先后调节对比、正交、提取次数和纯化试验,得到较佳工艺条件:采用先调pH值法,水溶液的pH值为12,提取时间为20 min,温度为室温,提取3次,通过pH5和7的两步沉淀,经干燥得到分离蛋白,蛋白纯度达84.8%,得率为38.9%,且有害物质残留较少.先调pH值法与后调法相比,总的提取率可提高20个百分点,达90%以上.     

酶法预处理对花生蛋白提取效果的影响(简报)

该文首次提出了以低温预榨花生饼为原料,经Viscozyme酶预处理后再碱溶酸沉提取蛋白质的新工艺,研究了酶处理条件对花生蛋白提取率的影响,通过中心组合试验设计和响应面分析优化的试验结果是：当花生饼浓度为15%,温度为45℃,酶用量1.26%,pH值为4.3,反应时间为134 min时,蛋白提取率为79.38%,而未用酶处理者蛋白提取率为58.35%,表明酶法预处理花生饼可以显著改善花生蛋白的提取效果。     

径流曲线法模型参数在黄土地区的优化研究

根系吸水的定量模拟是土-根系统水分动力学研究的难点之一.现有根系吸水模拟模型往往是在特定条件下建立的,缺乏对根系吸水机制的了解,因而其应用受到限制.根系吸水的最小能量模型是基于植物为适应生存,用于根系吸收水分消耗的能量最小这一物理概念上提出来,是否能真实反映根系吸水情况值得进一步研究.采用土柱实验,对该模型进行了实验验证.发现正常水分条件下,最小能量模型模拟精度高,而在土壤干旱条件下模拟精度较差,可能与干旱条件下植物体内的生物调节机制有关.     

电感耦合等离子体原子发射光谱法测定土壤中全硫、全磷和全钾

分别采用传统王水消解法和微波消解法处理样品,用电感耦合等离子体原子发射光谱法测定土壤中全硫、全磷和全钾的含量。该方法简单快捷,检测灵敏度高,线性范围宽,重复性好,准确度高,能同时测定土壤中全硫、全磷和全钾的含量,测定结果准确可靠,重现性及精密度很好,加标回收率在95.1%~100.4%之间。可使分析工作者从传统的分析手续冗繁、耗时的繁重工作中解放出来。     

汾河上游岚河流域非点源输出动态研究

氮、磷元素是造成水体富营养化的主要贡献因子之一,通过采用非点源污染物收支分析的方法,对汾河上游流域的岚河流域段进行非点源输出的动态研究,得出以下结论:该流域内总氮(TN)和总磷(TP)的浓度输出主要受其径流量影响;流域的截留率主要受流域的水生植物和微生物影响,TN截留负荷与径流量相关系数为0.724,TP的截留负荷、截留率和径流量相互间的相关系数均达到0.7以上;非点源收支分析方法对流域TN和TP的模拟平均误差率都控制在10%左右,TN的输出浓度和负荷模拟与实际监测的相关系数分别为0.895和0.924,TP的输出浓度和负荷模拟与实际监测的相关系数分别为0.896和0.997。     

西兰花叶中生物活性成分的测定

为探究西兰花叶中生物活性成分的具体含量,以西兰花叶为原材料,对西兰花叶中萝卜硫素、总酚、总黄酮、总蛋白质的含量和组成进行了测定与分析。结果表明,西兰花废弃叶中萝卜硫素含量为92.50μg·g^-1DW,总酚含量为3.15 mg·g^-1DW,总黄酮含量为2.48 mg·g^-1DW,总蛋白质含量为89.38 mg·g^-1 DW,蛋白质组成中核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)所占比例最大。本研究明确了西兰花叶片中4种生物活性成分的具体含量,为进一步开发利用西兰花废弃物提供了一定的数据支持。     

干旱区绿洲多介质环境中氮素和磷素分布研究

通过对绿洲内部不同环境介质定点采样和室内分析,研究了绿洲主要非点源污染物氮素和磷素在绿洲内部不同环境介质中的分布和相互迁移规律。研究发现绿洲河流中的氮和磷的含量呈现出沿河流流向上升趋势,河水中氮素含量最低值(0.399mg/L)出现在河流出山口,最高值(1.707mg/L)出现在人类活动密集区的绿洲核心地区,该值比源头的第一个最低值增加了3倍,相当于每1km约增加了9.6μg/L;河水中的磷素含量最低值同样是出现在了河流出山口,含量为3.13mg/L,最高值出现在绿洲末端,为26.46mg/L。农田土壤中的氮和磷的含量普遍高于农田边缘地区的非耕作土壤,不同农作物土壤中的氮和磷的含量也有所不同,稻田土壤中氮含量相对于别的农田较高为0.338g/kg,果园土壤中的磷含量较高为0.367g/kg。采集的农田排水中氮和磷的含量普遍比河水中的含量高,最高已高出3倍以上。不同环境介质中氮素和磷素含量相关性而言农田排水和河水氮素含量,农田土壤和河水中的磷素之间的相关性较高说明它们之间氮素和磷素的相互转移比较明显。     

Incorporation of catch crop residues does not increase phosphorus leaching: a soil column experiment in unsaturated conditions

Some studies suggest that incorporation of catch crop residues leads to increased availability of P to plants. However, little information is available on how this affects P leaching in soils with a high P load. We tested the effect of catch‐crop residue incorporation at the end of winter on the P leaching potential in a soil column experiment under unsaturated conditions using a typical sandy loam soil of NW Europe characterized by a high P load. We sampled the catch crops white mustard (Sinapis alba L.), Italian ryegrass (Lolium multiflorum L.), black oats (Avena strigosa L.) and a perennial ryegrass‐white clover mix (Lolium perenne L.‐Trifolium repens L.) from a field trial on catch crops and soil from the plots where they were grown. Plant biomass was incorporated taking account of the differences in conditions of the plant material at the end of winter and the biomass yield of each catch crop. Incorporation of catch‐crop residues decreased P leaching compared to the fallow treatment probably through immobilization of soil P during catch crop residue decomposition. The exception was black oats, where the leaching of P was the same as for fallow soil. We observed clear differences in C/N, C/P, water soluble and total P concentration, and biodegradability between the tested catch crops, which seemed to affect the P leaching. We conclude that the incorporation of catch crop residues under typical soil and weather conditions and agricultural practices of NW Europe does not increase the potential P leaching losses.     

Response of mango tree nutritional status and biochemical constituents to boron and nitrogen fertilization

Abstract

A field experiment was conducted at Al Malak Valley Farm, El-Sharkeya Governorate-Egypt (30°–51° N; 32°–53° E) using 15 years old productive mango (Mangifera indica L.) trees cv. Zebda. The experiment was repeated for two successive seasons (2014/2015) and (2015/2016). The trees were planted 8×8 meters apart in sandy soil under drip irrigation system using the Nile water. Treatments included three concentrations of boron (0.0, 250, 500?mg L^?1) and three concentrations of nitrogen (1000, 1250, 1500?g nitrogen/tree/year). Boron was applied as foliar spray of boric acid and nitrogen was applied to the soil as ammonium sulfate. Treatments were arranged in a factorial Completely Randomized Block Design with three replicates for each treatment. Results show that boron application has improved mango tree nutritional status. Leaf nitrogen, phosphorus, potassium and boron concentrations significantly increased as the boron application rate increased. In addition, boron application resulted in significant increase in leaf total chlorophyll, total carbohydrates, total sugars, carbon/nitrogen (C/N) ratio and decrease in total phenol content. Boron showed higher impact than nitrogen on all tested parameters. The interaction treatment of 250?mg L^?1 boron and 1500?g/tree nitrogen proved to be the best treatment.     

Spatial variability of total soil carbon and nitrogen stocks for some reclaimed minesoils of southeastern Ohio

Reclamation of drastically disturbed minesoils and subsequent planting of trees and/or grasses can result in a rapid build‐up of carbon (C) in the soil. However, the amount of C sequestered in reclaimed minesoils may vary with the amount of time since reclamation. In this study, we assessed total carbon (TC) and total nitrogen (TN) concentrations for reclaimed minesoils located in northeastern Ohio and characterized by distinct reclamation age chronosequences. Reclaimed minesoils studied were R78G, reclaimed in 1978 and immediately seeded to grass; R82GT, reclaimed in 1982 and immediately seeded to grass and trees were planted 5 years later; and R87G, reclaimed in 1987 and immediately seeded to grass. An unmined site, UMG, was also included as a reference. Our objectives were to evaluate the variability with respect to mean and the spatial variability of pH, bulk density (ρ_b), TC and TN concentrations, and stocks in each reclaimed minesoil. Thirty soil samples were collected at each of the 0–15, 15–30, and 30–50 cm depth. The coefficient of variation (CV) for ρ_b was least, <15 per cent at each site and depth. For TN concentration and stock, CV was moderate, 15–35 per cent, in each field except the UMG where it was high, >35 per cent at 0–15, and 15–30 cm depths. For TC concentration and stocks, CV was high, >35 per cent, across all minesoils and generally increased with depth. The C/N ratio followed the same tend as TC and TN stocks and ranged from 40 per cent to 123 per cent across minesoils. Geostatistical analysis also showed an increase in sample variance with increasing amount of time since reclamation for most soil properties under investigation. Sample variance for TC concentration and stocks also increased with depth in reclaimed minesoils. However, no definite relationship emerged between amount of time since reclamation and the spatial dependence of TC and TN concentrations and stocks. Overall this study showed that reclamation of drastically disturbed minesoils increased the soil C concentration and stocks and reclamation by initially seeding to grasses followed by planting trees was the best management option for speedy accretion of soil C and soil quality enhancement. Copyright © 2007 John Wiley & Sons, Ltd.     

太湖流域规模畜禽养殖场污染特性的解析

通过对江苏省太湖流域水污染防治一级保护区内规模畜禽养殖场的调查 ,揭示了其污染物的存在方式、处理形式等特性。调查表明 ,规模畜禽养殖场并非是构成太湖水质下降的“污染大户” ,为正确探索太湖水质下降的成因和防止太湖水质继续恶化 ,提出了新的思路和建议。     

河岸带对地表径流截污的小试模拟以及不同基质处理表渗流能力的比较

采用潮白河河岸带土壤,设置不同基质填充类型的小试模拟装置,依照北京市降雨径流水质进行模拟径流配水,研究不同基质材料处理径流污染的能力,同时比较表渗流去除污染物的差异,以期强化河岸带截污能力,减少进入水体中的外源污染物。结果表明,将对照以及火山岩、砾石、石灰石、白云石和沸石作为改造基质的系统截污能力进行比较,总体而言,对于污染物的去除效果较佳的是沸石组,其在TN、TP以及COD的去除方面均表现出了一定的优势。对NH_4~+-N而言,处理效果最好的是沸石组,去除率达到了60.65%。同时,土壤组的表渗流量比为1.73,而沸石组的表渗流量比为1.02,COD和氮磷污染物的总去除率均与表渗流量比呈显著负相关。对河岸带选择合适基质进行一定的改造,不仅有利于提高截污性能,还可以降低表渗流量比值,提高下渗水量,从而利于地下水的补充。