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。     

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。     

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。     

Lactobacillus amylophilus JCM1125在生长限制条件下的代谢特性

在以小麦淀粉、玉米淀粉、马铃薯淀粉和可溶性淀粉为碳源代替葡萄糖为碳源的 MRS培养基上检测了菌株 L actobacillus amylophilus JCM112 5活菌数的增殖状况以及葡萄糖和有机酸的代谢特征同时测定了 p H值的变化。结果表明以淀粉为碳源时菌株先分解淀粉成葡萄糖并累积到一定数量后再加以利用 ;活菌数呈现双曲线增长现象 ;丙酮酸、乳酸、乙酸和柠檬酸及另一未知有机酸的数量发生了较大的变化。     

江西烤烟淀粉近红外检测模型的建立

【目的】传统的碘显色法检测淀粉含量需要复杂耗时的前处理和实验准备,近红外检测手段不仅 操作简单、检测快速,且不损耗试剂、样品、标准品,大大降低了检测成本,旨在以江西烤烟样品为依托,建 立一种适用于江西烤烟的淀粉近红外检测模型。【方法】收集了来自江西 21 个区县共 650 个烤烟样品的近红外 光谱和对应的连续流动分析仪检测数据（碘显色法）,将光谱数据和化学分析数据一一对应,使用不同的回归 方法和数据处理方法进行建模,通过比较它们的均方根误差和相关系数确定最佳的模型参数。【结果】建立了 适用于江西烤烟的淀粉含量预报模型,校正均方根误差和预测均方根误差分别达到 0.407、0.490,相关系数为 96.52%,并用外部样品对模型进行了验证,95% 的样品误差在 10% 以内。【结论】该模型可用于快速检测江西 烤烟样品中的淀粉含量,并可在一定程度上取代传统的碘显色测淀粉法,降低了检测成本,提高了分析效率。     

作物抗性淀粉研究进展

抗性淀粉(resistant starch,RS)是一种健康的膳食纤维,能够降低血糖和血脂,对预防和改善肥胖症、糖尿病、心血管疾病和慢性肾病等非传染性疾病具有重要作用。抗性淀粉在面包、饺子等高品质食品的开发中具有潜在的应用价值,是近年来功能食品领域研究的热点。总结归纳了RS的功能和类型,着重对合成RS相关的酶进行了阐述,并对高RS作物分子育种研究进展进行归纳,以期为作物RS研究和分子育种提供参考。     

Fast measurement of starch content in cold-treated seedlings by infrared spectra

Despite the importance of starch for tree growth, methodological challenges in starch analysis slow down the research on its ecological importance. In this study, a rapid monitoring method was developed for measuring starch content in Pinus taeda L. seedlings after cold treatments. A linear mixed-effects model was used to analyze the effects of cold treatments, seedling tissue types and their interaction on starch content. Mid-infrared (MIR) and near-infrared (NIR) spectra were surveyed, and the results were analyzed using partial least squares regression to determine the starch content. The determination coefficient for calibration and residual predictive deviation were compared between MIR and NIR models to assess the variability of the established models. The results showed that the effects of cold treatments, seedling tissue types and their interaction on starch content were significant. Compared to MIR spectra, NIR spectra is more suitable to estimate starch content in the seedlings. Using NIR spectra, roots provided the most accurate estimates of starch content. The presented guidelines regarding data accuracy as a function of MIR/NIR spectra of samples represent an important methodological reference for starch quantification, which will improve the understanding of the fundamental role of starch in seedlings against environmental forces.     

Electron microscopic observations of sooty moulds on crape myrtle leaves

Sooty moulds on crape myrtle leaves were investigated using light and electron microscopy. The adaxial leaf surface was distinctly covered with soot‐like masses of dark brown hyphae and conidia. The main characteristics of the sooty moulds included stauroconidia, conidial clusters, hyphal degeneration and extracellular melanin depositions. Some conidia were round, measured ~10 μm in diameter, and mostly one‐septate; others were branched and multiseptate (stauroconidia). Based on their morphology, the sooty moulds were determined to consist of several component fungal species belonging to genera such as Antennaria, Metacapnodium and Tripospermum. Enclosed in electron‐dense melanin layers, hyphae and conidial clusters had concentric bodies exhibiting electron‐transparent cores and electron‐dense shells with fibrillar sheaths. Concentric bodies are hypothesized to function as multilayer lipid‐encapsulated nanobubbles or eukaryotic gas vesicles for cytoplasmic volume control. Intrahyphal hyphae possessed electron‐dense cytoplasm and lipid globules. These results suggest that sooty moulds are equipped with melanized cell walls, multicelled resting structures, hyphal regeneration, intrahyphal growth and gas vesicles to adapt to their xeric phylloplane environment. Condensed and elongated starch granules in the chloroplasts of mesophyll tissues may indicate the acclimation of the sooty leaf regions to light reduction and temperature increase.     

短链葡聚糖-姜黄素纳米乳液的制备及结构表征

利用短链葡聚糖(short glucan chains,SGC)的螺旋空间结构来包埋姜黄素(curcumin,CUR)。通过使用高剪切分散乳化机高速剪切溶液5 min,用纳米均质机在50 MPa压力下高压均质经剪切后的乳液2次制备成纳米乳液以提高其包埋率和载药量。XRD (x-ray diffraction)和TGA (thermogravimetric analysis)很好的验证了包合物的形成,通过TGA、SEM (scanning electron microscopy)、激光粒径分析仪等各种表征分析得出短链葡聚糖-姜黄素纳米乳液制备成功,所制得的乳液对姜黄素的包埋率和载药量都高于短链葡聚糖-姜黄素包合物,分别达到了71.11%和12.07%,说明制备成纳米乳液对姜黄素的包埋率和载药量都有了明显的提高。所制备的纳米乳液的粒径小于300 nm,粒径分布均一,Zeta电位观测表明所制得的乳液的稳定性有所提高。为提高食品及医药领域姜黄素的生物利用率提供了一定的参考意义。