以绿豆淀粉为研究对象,以吸油率为指标,通过改变水热处理中的各试验因素及范围,建立多孔淀粉的制备方法.并采用激光粒度仪、压汞仪、扫描电子显微镜、X-射线衍射仪等对多孔淀粉的理化性能和结构性能进行表征.结果表明:当淀粉乳浓度为 2.0％,处理温度为 78℃,处理时间为 13.0 min时,可以获得多孔淀粉,其吸油率和得率分别为 69.8％和 84.6％.性能表征结果显示多孔淀粉直链淀粉含量、平均粒径、比表面积、孔隙率和中值孔径分别为14.2％、63.4 μm、0.694 m2/g、67.5％和 5.2 μm,其形态呈颗粒状,表面为类似淀粉凝胶网络的多孔结构.相较原淀粉,多孔淀粉的相对结晶度和短程有序度均较低.

产教融合不仅是当前及今后一段时间内职业教育改革应当遵循的指导理念,也是职业教育提升办学水平的重要方式.文章以高职化妆品专业为例,以化妆品人才需求为导向,从课程理念、课程内容、课程技术、课程制度四层面进行一体化设计,提出基于产教融合的高职化妆品课程体系"三驱动,四融通,二实施,一评价"模式的创新方案,对于丰富专业课程体系,提升人才培养质量,助力产业高质量发展具有重要意义.

高职教育专业结构作为衔接职业教育与地方产业结构的纽带,不仅决定了职业教育服务产业结构的程度,还决定了职业教育建设的好坏.目前,陕西省产业结构发展与高职教育专业结构的匹配度仍需进一步加强.在此背景下,具体建议包括:基于产业结构变化及时调整专业布点数;紧贴产业结构变化打造地区高水平专业群;以产教融合为出发点挖掘优质就业专业;构建多元主体专业结构设置方式;设立科学的专业结构发展评价机制.

本文介绍了淀粉基膜的制备和性能.详细对比了淀粉基膜制备过程中淀粉种类、塑化剂种类、其他添加剂以及淀粉的改性处理对其性能的影响,探讨了淀粉基膜的应用现状,并对今后淀粉基膜的研究进行了展望.

针对煤泥结构特性及利用现状,本文以腐殖酸钠(SH)和木质素磺酸钠(SLS)为研究药剂,探究了不同分散剂在煤泥表面的吸附性能,并借助分子模拟手段揭示了药剂在煤泥主要组分表面的作用机制.结果表明,SH和SLS在煤泥/兰炭表面的吸附动力学过程遵循准二级动力学方程,拟合所得相关系数R2均大于0.99,分散剂在颗粒表面的吸附受化学吸附控制.同时,SLS在水/煤界面和水/高岭石界面都具有较优的吸附性能,说明SLS更易于与在煤泥内主要组分发生吸附,吸附SLS后高岭石体系水分子的扩散系数D降低至6.69 × 10-9 m2·s-1,从微观层面解释了 SLS在煤泥表面的吸附量大于腐殖酸钠以及加入木质素磺酸钠能更明显改善含煤泥燃料浆浆体性能的原因.

准确测定和合理配制乳粉中各种营养元素含量对乳粉的品质及人体健康极为重要.本文采用电感耦合等离子体发射光谱法对不同种类的乳粉中8种常微量元素进行测定,并对其各元素含量差异进行对比和分析,为乳粉营养品质评价以及合理配制各营养元素含量具有一定的指导意义.

以绿豆淀粉和大豆分离蛋白为制膜原料,通过考察二者复合比例对可食性绿豆淀粉基复合膜性能的影响,研究可食性绿豆淀粉基复合膜的最佳复合比例,同时利用傅里叶红外光谱仪和扫描电镜对该复合膜进行结构表征,并考察其对青脆李贮藏品质的影响.结果表明:在绿豆淀粉与大豆分离蛋白复合比例为2:1时,绿豆淀粉基复合膜表现出良好的膜性能,此时溶解度、水蒸气透过系数、抗拉强度和断裂伸长率分别为18％、1.2×10-5 g·mm·cm-2·h-1·Pa-1、35 MPa和21.4％.与绿豆淀粉膜相比,该复合膜组分间的相容性较好,且表面更平滑、均匀.在常温贮藏期间,用该复合膜涂膜的青脆李硬度、可溶性固形物和可滴定酸含量等品质指标均优于未涂膜组,可作为青脆李的保鲜膜材料.

将紫苏籽粉碎过60目筛后采用石油醚脱脂得到紫苏籽脱脂粉,采用osborne法提取紫苏球蛋白,研究其乳化性质,并将其应用于水包油(oil in water,O/W)乳液,进一步研究紫苏球蛋白浓度对乳液稳定性影响.结果表明,紫苏脱脂粉中球蛋白含量较高,其溶解性、乳化活性和乳化稳定性在pH 2～9,呈现U型曲线;球蛋白质量浓度为2.5～12.5 g/L时,随蛋白质量浓度增大,乳状液粒径、絮凝指数、凝结指数均逐渐减小,界面蛋白含量和质量浓度增加;在14 d贮存过程中,蛋白质量浓度低于7.5 g/L的乳状液均发生脂肪上浮现象,高于10 g/L的乳液贮存稳定性良好.

本文针对焦化废水处理难的现状,选取陕北兰炭粉作为研究对象,引入焦化废水作为第二相制备高性能兰炭基燃料浆,并探究焦化废水对兰炭粉成浆性的影响.结果表明,与常规制浆方法相比,焦化废水的引入对兰炭粉的成浆性起到了促进作用,所制兰炭基燃料浆呈现出更好的流动特性.相同制浆条件下,焦化废水兰炭浆具有更低的表观粘度,浆体最大固体浓度(SCmax)可达66.69(wt)％,且静置7d无硬沉淀产生.同时,焦化废水的加入可以从一定程度上增加兰炭浆的挥发分含量,使得浆体的着火温度(Ti)和燃尽温度(Th)均降低,燃烧性能优于普通兰炭浆.

Amorphous granular starches from six different botanical sources were obtained by heating starch suspensions in water at or near pasting temperature. Their morphology was divided into two types: one was ghost-like with openings on the surface (sweet potato, tapioca, wheat and maize starches), and the other was gel-like with the surface porous structures (mung bean and pea starches). Their mean particle sizes (D50), specific surface areas, amylose contents, and molecular gyration z-average radii (Rz) were 30.6-57.0 mu m, 0.359-0.649 m2/g, 13.7%16.8%, and 88.9-115.3 nm, respectively. The amorphous granular starches showed better cold-water solubility (78.5%-94.2%), oil-adsorption capacity (43.1%-62.1%) and enzymolysis rate (58.5%-82.6%) characteristics at room temperature than those of the granular cold-water soluble (GCWS) starches and the pre-gelatinized (PG) starches. They could be used as thickening agents, adhesives, carriers of liposoluble function factors and basic materials of throat lozenges.

For more effective using of HHP (high hydrostatic pressure) in starch processing, in this study, molecular dynamics simulation was used to explore the effects of pressure on amylose molecular conformation at the atomic level. The results shown that, firstly, high pressure decreased the intramolecular hydrogen bonds and increased the amylose-solvent hydrogen bonds, which is consistent with the process of high pressure starch gelatinization. Secondly, high pressure made amylose polymers more "stout". Meanwhile, high pressure decreased the angle of α-1,4 glycosidic linkage and increased the dihedral angles of α-1,4 glycosidic linkage, which indicates that pressure has obvious effects on amylose molecular conformation. Thirdly, high pressure made amylose polymers more stable. Moreover, in view of the results of energies, HHP may have an opposite gelatinization mechanism to heating. The results may be complementary to the existing experimental phenomena and provide theoretical guidance value for the using of HHP in starch processing.

Honeycomb-like granules, with 2-4 μm pores on the surface, were prepared by heating potato starch suspensions in water at the pasting temperature. These granules with a yield of 84% were most amorphous (relative crystallinity 1.9%). Their total pore area was 0.668 m2/g, porosity was 73.4%, and mean particle size (D50) was 154.3 μm. The molecular weights (MW) of honeycomb-like granules were: amylopectin, 8.7 × 107 g/mol; amylose, 3.1 × 105 g/mol, close to those of native starch. The chain length distribution profiles of honeycomb-like granules were similar to those of native starch, while the proportions of B2 and B3 chains were higher. The water and oil adsorption of honeycomb-like granules were about 1.5 and 2.4 times those of native starch, respectively; and the cold water solubility of honeycomb-like granules was 88.5%, while native starch showed no solubility in cold water. Thus honeycomb-like starch granules have the potential to be applied as adsorbents, thickeners and adhesives for their dispersibility, adsorption capacity and cold water solubility.

Starch is an important resource in nature, and HHP (high hydrostatic pressure) is one of the most important physical modification technologies. In this study, molecular dynamics simulation was used to explore the interchain interaction and the changes of molecule conformations of amylopectin and double-amylose helix at atomic level in different pressure. The results shown that, firstly, high pressure increased the content of 4C1 chair conformation, decreased the RMSD (root mean square deviations) and RMSF (root mean square fluctuation), made molecules more stable. Secondly, high pressure increased the interchain VDW (Van der Waals) and electrostatic forces, then caused the decreases of the interchain distances and surface area of both amylopectin and double-amylose, made molecules more compact. Thirdly, high pressure decreased the intramolecular hydrogen bonds, increased the molecule-solvent hydrogen bonds. These findings can explain some existing experimental phenomena from the atomic level, meanwhile, it may also provide importance reference value for using of HHP in starch processing and the studies of starch granule structure.

Starch is a basic biomacromolecule, and an in-depth understanding of the process and mechanism of starch-lipid complexation has great significance for starch based food and pharmaceutical. In this study, molecular dynamics simulation was used to explore the complexation details between starch molecules and trilinolenin, such as complexation process, interaction forces, conformation changes and stability changes, which are difficult to be verified by using other characterization methods. The results show that, firstly, starch residues of one turn helix (8 residues) are enough to bind a trilinolenin molecule firmly. Secondly, the complex is maintained by Van der Waals and electrostatic interaction. Thirdly, the residues complexed with trilinolenin become more stable than the former or the free residues. In brief, the complexation process, interaction forces, conformation changes and stability changes of the starch-trilinolenin complex were clarified in this study. The results may create new insights for the research about the interaction of starch and lipid, then provide theoretical guidance for the research on starch based food and pharmaceutical.

以薯类(红薯、木薯)、豆类(豌豆、绿豆)和谷类(玉米、小麦)淀粉为研究对象,在淀粉糊化温度测定的基础上,通过降低温度和pH值,研究了不同淀粉颗粒外壳的分离方法.结果 表明,将最高处理温度与淀粉糊化温度差值设置为-16～15℃,在乙酸溶液(pH值1.5、浓度7.1 mol/L)中对淀粉颗粒进行处理,糊化程度为19％ ～56％时,可以得到不同淀粉的颗粒外壳,厚度为50 ～ 470 nm.除绿豆淀粉外,其他淀粉颗粒外壳的分子量(4.3×107 ～5.2×107 g/mol)均大于原淀粉的分子量(3.8×107 ～4.7×107 g/mol).不同淀粉外壳的厚度与其粒径、直链淀粉质量分数以及相对结晶度没有明显的相关性.玉米淀粉的颗粒外壳结构相对完整,可作为生物大分子缓释自组装包膜材料.

The effect of repeated heat-moisture treatment (RHMT) on the structural characteristics of waxy maize starch nanocrystals was investigated. Compared with native waxy maize starch (WMS), waxy maize starch nanocrystals (WMSNs) changed the crystalline pattern from A-type to B-type, and displayed the lower crystallinity (RC), molecular order (MO), enthalpy (∆H) and double-helix (DH) content, indicating a reduction in the long- and short-range orders of starch molecules. Single heat-moisture treatment significantly increased values, including RC, MO, α (power law exponent obtained by SAXS), ∆H, DH, and the melting temperatures (To, Tp and Tc), while repeated heat-moisture treatment further increased values of these parameters except ∆H, indicating the reinforcement of the long- and short-range orders of WMSNs. In addition, repeated heat-moisture treatment also caused a gradual conversion from B-type to “A + B”-type (Cb, Cc to Ca polymorphs in sequence) and finally to A-type crystallites.

紫苏油作为一种营养保健食用油,含有高达65% 的亚麻酸,而亚麻酸含有三个双键,是一种不饱和脂肪酸,极易氧化 .为了提高紫苏油的稳定性,采用明胶/阿拉伯胶复合凝聚结合冷冻干燥对紫苏油进行了包埋.研究了壁材浓度、pH值、芯壁比和搅拌速度等因素对复合凝聚紫苏油微胶囊形态的影响,确定了以明胶-阿拉伯胶为壁材复合凝聚包埋紫苏油微胶囊的最佳实验室工艺条件为:明胶:阿拉伯胶=1:1、芯壁比为1:1、壁材质量分数为1% 、pH3 .9、搅拌速度300 rpm .在此条件下得到的微胶囊经光学显微镜与扫描电子显微镜形态观察,其结构完整,形态均一,分散均匀 .

为了同步研究淀粉颗粒表面小体和壳层结构,用 α-淀粉酶、β-淀粉酶和普鲁兰酶,在室温下单一或复合酶解马铃薯、红薯、木薯淀粉颗粒,用扫描电子显微镜观察酶解颗粒并进行性质测试.研究结果表明,单一酶作用时,只有 α-淀粉酶可使3种薯类淀粉显露颗粒表面小体(直径29～73 nm)和壳层结构(厚度150～400 nm);马铃薯淀粉的酶解率(1.1％)远低于其他2种淀粉的(14.1％、16.3％).马铃薯淀粉表面小体的排列较紧密、壳层结构较致密,决定了其具有较强的抗酶解性和较大的峰值黏度(即膨胀能力).复合酶作用时,α-淀粉酶复合与其单一作用的效果类似.因此单一α-淀粉酶有限酶解法可以作为淀粉颗粒表面小体和壳层结构的研究方法,酶解条件为:酶浓度80 U/mL,室温下酶解12 h.该研究结果为淀粉类产品在实际加工过程中的品质控制提供了理论基础.

The determination methods of starch molecular weight, including gel permeation chromatography, asymmetrical flow field flow fractionation and viscosity methods were reviewed. The molecular weight distribu-tion of different native starches, the modification methods of starch molecular weight, and the relationship be-tween molecular weight and physicochemical properties were summarized. Future research directions on molec-ular weight of starch were prospected.