内蒙古高原紫花苜蓿土壤氮素丰缺指标和推荐施氮量

为了给内蒙古高原紫花苜蓿（Medicago sativa L.）测土施氮奠定科学基础，本研究采用“零散实验数据整合法”和“养分平衡-地力差减法”新应用公式，开展了该自然区域紫花苜蓿土壤氮素丰缺指标和推荐施氮量研究。结果表明：内蒙古高原生长第1年紫花苜蓿土壤碱解氮第1~6级丰缺指标为≥48，20~48，8~20，4~8，2~4和<2 mg·kg^-1，土壤全氮第1~5级丰缺指标为≥1.4，0.8~1.4，0.4~0.8，0.2~0.4和<0.2 g·kg^-1，土壤有机质第1~6级丰缺指标为≥17，10~17，6~10，3~6，2~3和<2 g·kg^-1。当紫花苜蓿目标产量9~18 t·hm^-2、氮肥利用率40%时，内蒙古高原紫花苜蓿第1~6级土壤推荐施氮量分别为0，68~135，135~270，203~405，270~540和338~675 kg·hm^-2。     

东北梅花鹿茸不同部位水解氨基酸含量的比较分析

对 10支东北梅花鹿茸作了不同部位水解氨基酸含量的比较分析 ,结果表明 ,水解氨基酸含量在东北梅花鹿茸腊片、粉片、血片和骨片各部位之间差异极显著 (P <0 0 1)。     

以豆粕为原料制备反刍动物饲用肽的研究

本文通过正交试验,选用碱性微生物蛋白酶,研究得出酶解法制备大豆肽的最佳工艺参数:豆粕预处理条件为90℃水浴加热10min,酶解条件为底物浓度5%(W/V)、加酶量5万单位/g蛋白质、温度50℃、pH值10、酶解时间5.5h。蛋白质水解率达到25%,平均肽链长度为4.0。制得大豆肽粗蛋白质含量66.83%(DM)。并对制得大豆肽和原料豆粕的氨基酸含量进行分析。     

用酶法制备藏羊血食用蛋白粉的研究

采用四因素三水平正交试验,对藏羊血制备食用蛋白的工艺进行了分析。经分析食用蛋白粉水解最佳条件为：酶解用酶量4.5g,酶解温度为46℃,酶解时间为7.5h,酶解的pH值为10.5,活性炭作用于水解液时由室温升至80℃所需最佳时间为6～8min。     

Hydrolysis and Condensation of Silane Agent for Metallic Surface Treatment

Novel surface treatment technique by silane film is developing for metallic anti corrosion and coat improvement. The key points, hydrolysis and condensation, for the stability of the Silane agent(SA) solution is investigated, and the effective factors of stability for silane agent solution and the relative rule are discussed. It is found that stability of SA solution is related to the temperature, pH, solvents, SA concentration and additive by studying the state of the solution and the conductivity-time curve of SA solution. Meanwhile, controlling factors and improving methods for SA stability are proposed to guide the practical application of metallic surface anti-corrosion treatment by SA.     

Degradation Studies of the Non-lethal Bird Repellent,Methyl Anthranilate

Methyl anthranilate (MA), a food grade flavor and fragrance additive, has been reported to be an effective non-lethal bird repellent in a variety of situations. Despite the experimental success of MA, field studies have yielded widely differing levels of efficacy. Diminished efficacy in some field trials probably results from the failure of specific formulations to retain or protect the active ingredient under natural conditions. Therefore, a clearer understanding of the physical and chemical factors affecting the stability of MA is needed. We undertook a series of laboratory studies on hydrolysis, photolysis and microbial degradation of MA, the results of which could be useful in the development of appropriate formulation strategies and residue analyses. We found the n-octanol:water partition coefficient, (P) to be 84. MA is not subject to hydrolysis at 25°C in phosphate buffer media at pH 5·0, 7·0 and 9·0. MA slowly photodegrades under simulated UV ‘sunlight’. Forty-four percent of MA is lost after 432 h illuminance at 1·25 mW cm⁻², which is equivalent to approximately 1200 h natural sunlight (40°N, noontime, June). Kinetic data indicate that the initial step of photolysis, subsequent to excitation, is a second-order reaction with respect to MA. A major photodegradation product appeared in an amount of about 10% of the mass balance and was determined to be an oxidized trimer of MA. MA is primarily affected by aerobic microbial degradation. For a 12:12 h light:dark, under laboratory illumination, 12% of water-solubilized material can be lost in the first seven days. Losses were 30% and 42% at 16 and 27 days, respectively. Under conditions of optimal bacterial growth (warmth and darkness) loss of MA was 22% at nine days and 100% by 20 days. The susceptibility of MA to microbial degradation is promising for the prospects of developing formulated, environmentally safe, bird repellents.     

扇贝加工废弃物蛋白酶解及其酶解产物分子量分布的研究

对用复合酶酶解扇贝加工废弃物制备水解蛋白的工艺进行了研究,通过正交试验方法确定了用两种复合酶酶解的最适水解条件。结果表明,用枯草杆菌中性蛋白酶和风味酶复合酶酶解的最佳酶解参数为:加酶量比为2∶1,温度为65℃,pH为7.0,时间为5 h,水解液氨基酸态氮含量为50.3%,蛋白质水解度为95.5%。用木瓜蛋白酶和风味酶复合酶酶解的最佳酶解参数为:加酶量比为2∶1,温度为65℃,pH为7.0,时间为5 h,水解液氨基酸态氮含量为43.2%,蛋白质水解度为85.0%。用SephadexG-15葡聚糖凝胶柱层析法对水解产物的分析结果表明,两种混合酶的酶解产物为蛋白肽和游离氨基酸,其相对分子质量均集中分布在585和150左右。     

水热预处理竹材制备低聚木糖和单糖的研究

以贵州慈竹为研究对象,对其进行水热预处理(LHWP),研究不同预处理强度系数对竹材化学组分、酶水解性能及低聚木糖(XOS)浓度的影响.利用X射线衍射(XRD)和傅里叶转换红外线光谱分析仪(FT-IR)分析预处理前后物料的物理和化学结构变化.研究结果表明:水热预处理过程中竹材的半纤维素含量显著降低,而纤维素及木质素的含量...     

酸枣幼根原生质体的制备

以生长6～9 d的酸枣种子幼根为试验材料,0.7 mol·L-1甘露醇作为渗透压稳定剂、pH值5.5～6.0、28℃恒温水浴条件下,以光学显微镜观察的水解总时间、初始产生原生质体的时间、原生质体产量及细胞碎片量为指标,研究通过酶水解来制备酸枣幼根原生质体的方法.结果表明,在含1％果胶酶+4％纤维素酶R-10+3％纤维素...     

蛋白酶解对鲣鱼肉乳化特性的改善

天然鱼蛋白乳化性不佳,难以满足实际生产需求,但鱼蛋白的酶解改性可改善其功能特性,并拓展应用范围。以鲣鱼白色肉为原料,以水解度和乳化性为主要指标,比较了不同蛋白酶(胰蛋白酶、风味蛋白酶、木瓜蛋白酶)和水解时间对酶解液制备和鱼蛋白乳化性的影响,优化了酶解工艺参数。将鱼蛋白进行冷冻干燥后,分析鱼蛋白酶解前后溶解性、乳化性和起泡性等功能特性的差异。结果表明,当胰蛋白酶添加量2 000 U·g^-1,酶解10 min时,鱼蛋白水解度(DH)达到8.2%,此时鱼蛋白乳化特性最佳。与酶解前样品相比,酶解后鱼蛋白的乳化活性和乳化稳定性显著提高,其溶解度、起泡性和起泡稳定性均有一定程度的改善。酶解制备的鲣鱼蛋白在广泛pH范围内具有更好的功能性质,在食品工业具有更高的应用价值。