收获期木薯地耕作层土壤硬度的试验研究

采用田间物理测定和数理统计分析方法,测定了收获期木薯种植地耕作层不同深度的土壤硬度,建立了耕作层深度与土壤硬度的数学模型,分析了土层深度对土壤硬度的影响规律。结果表明:建立的木薯地耕作层土壤硬度与深度的数学模型精度高,硬度与深度基本上成3次方的非线性关系;采用盖膜方式种植的木薯地,其土壤硬度先随土层深度的增大而增大,后随土层深度的增大而缓慢增大或减小;不采用盖膜方式种植的木薯地,其土壤硬度先随土层深度的增大而减小,后随土层深度的增大而增大,最后又随土层深度的增大而减小。     

豆制品加工中黄浆水无害化处理技术研究

对豆制品中黄浆水进行超滤处理的工艺参数进行研究。用外加压管式膜组件对黄浆水进行了超滤试验,分析了液体分别在不同的温度、压力、流速、pH值等因素下对渗透流量和截留率的影响。通过正交试验,得到了处理黄浆水废液的最佳工况。实验结果表明,超滤处理黄浆水的最佳工况是:在压力0.15MPa下,用泵的最大流量对刚排放的黄浆水(温度55℃左右)进行超滤处理,可回收全部脂肪、75%以上的蛋白质和70%以上的总糖。回收后的浓缩物(或干燥物)可以作为饲料或经纯化后食用。     

Determination of Molecular Weight and Distribution of Hyroxyethl Starch (HES) by Means of GPC- RI- MALLS Technique

The author introduces a method and experimental procedures that determine dn/dc,molecular weight and its distribution of the hyroxyethyl starch(HES) by means of Gel Permeation Chromatography-Refractive index-Multi-angle laser light scattering detection(GPC-RI-MALLS)techniques.The key experimental technique and results are discussed.The method takes CH3COOH/CH3COONa as mobile phase and solvent.The experiment gets satisfactory results.It can be used as a routine method to determine the hyroxyethyl starch(HES) molecular weight and its distribution.     

酶—湿热处理对锥栗淀粉理化特性的影响

采用酶-湿热处理锥栗淀粉,研究酶用量与脱支时间对复合变性锥栗淀粉理化特性的影响。结果表明:酶-湿热处理锥栗淀粉的晶型均为A型,且预期血糖指数(p GI值)大多低于55%,属于低p GI值食品。由体外消化动力学分析、扫描电子显微镜、X-射线衍射、差示扫描量热、高效阴离子色谱-脉冲安培检测等实验分析得出,酶-湿热处理锥栗淀粉的抗性淀粉含量、分子链平均聚合度(DP值)、相对结晶度和熔融焓等随酶用量和脱支时间的变化表现为3个阶段,尤其在第2阶段,即当酶用量在50~60 U/g且反应时间在12~16 h范围内时,因分子链DP值适合重新聚合形成稳定的结晶结构,抗性淀粉含量、相对结晶度和熔融焓均达到最大。     

Late nitrogen fertilization affects carbohydrate mobilization in wheat

An experiment was carried out to determine how the late application of nitrogen (N) fertilizer affects the use of pre‐anthesis carbon reserves during the grain‐filling period of pot‐grown wheat with no water shortage. Increasing doses (equivalent to 0, 140, and 180 kg N ha^–1) of N fertilizer were applied, either in two amendments (stages GS20 and GS30) or in three amendments (stages GS20, GS30, and GS37, according to Zadoks scale). The management of fertilizer by combining an increased N rate with late N application was able to stimulate canopy development, to raise photosynthetic capacity and carbohydrate accumulation during the vegetative stages, and to increase grain yield. Based on the dynamics of carbohydrate accumulation in the ear, three phases were differentiated during the grain‐filling period, whose temporary pattern remained stable regardless of the fertilizer management. The net remobilization of carbohydrates started 12 d after anthesis from the leaves and 28 d after anthesis from roots and stems. The increase of the N dose with late N application allowed on one hand a lower use of the pre‐anthesis carbon reserves in favor of greater de novo photosynthesis during the grain‐filling period, and on the other hand greater relative contribution of the leaf and ear C reserves to remobilization towards the grain. Further splitting the dose increased only the relative contribution of ear C reserves. The stem contribution seemed to be independent of N applied whereas the root contribution tended to diminish with late N application.     

淀粉共生蛋白对淀粉水解的影响

以小麦面粉为原料,研究了淀粉共生蛋白对淀粉酶解性质的影响。对洗淀粉过程中影响蛋白含量的条件进行了单因素试验,用SDS溶液和蛋白酶进一步除去淀粉中的蛋白质成分,然后对制得的含氮量不同的淀粉样品进行酶解。试验结果表明,蛋白酶能有效地去除淀粉共生蛋白,而淀粉共生蛋白有助于淀粉的水解。     

微波技术在变性淀粉研究中的应用现状

介绍了微波改性淀粉的原理,综述了近年来微波技术在变性淀粉研究中的应用现状。     

Effect of biocontrol agents and biofertilizers on root rot,yield, harvest index and nutrient uptake of cassava (Manihot esculanta Crantz)

Cassava is an important subsidiary food and industrial raw material in the tropics. Root rot disease, caused by Phytophthora palmivora, poses a serious threat to cassava cultivation in Tamil Nadu, India. Field experiments (2008–09) were conducted to study the effect of biocontrol agents (Trichoderma spp. and Pseudomonas fluorescens) and biofertilizers (Azospirillum, vesicular–arbuscular mycorrhizal fungi and phosphorus-solubilizing bacteria) on root rot, yield, harvest index and nutrient uptake of cassava at two NPK rates. The design of the experiment was a split plot with two NPK rates, recommended and 50% recommended rate, as the main plot treatments and five biocontrol agents and biofertilizers as subplot treatments. The results clearly indicated that use of a bioinoculants consortium significantly reduced root rot infection/disease incidence over uninoculated controls. Azospirillum significantly improved the yield of cassava at 50% of the recommended rate of NPK. NPK rates had no significant impact on harvest index of cassava and Trichoderma and vesicular–arbuscular mycorrhizal fungi resulted in a higher harvest index even at 50% of the recommended NPK rate. Nitrogen, phosphorus and potassium uptake was significantly improved when treated with biofertilizers and/or a consortium.     

华北落叶松和白杆幼苗脯氨酸及淀粉含量对水分和光照变化的响应

以2年生华北落叶松和白杆幼苗为研究对象，通过人工控制条件下的幼苗栽培试验，测定不同光照、水分条件下脯氨酸含量、淀粉含量的变化，综合比较分析了华北落叶松和白析苗期生长对光照和水分变化的生理响应。研究结果表明：随着土壤水分的减少，华北落叶松和白不工幼苗脯氨酸含量增高，淀粉含量下降，且华北落叶松的变化都高于白杆，华北落叶松幼苗比白析幼苗对土壤水分胁迫的响应能力更强；随着光照的增强，也有相同的表现。光照和水分条件的变化对华北落叶松和白析幼苗脯氨酸和淀粉含量的影响具有叠加作用，2个树种对水分胁迫和强光照的响应机制一致，但树种间响应强度不同，华北落叶松的响应能力更强，华北落叶松具有比白术千更大的抗干旱胁迫的生理基础。