FA composition and regiospecific analysis of Acer saccharum (sugar maple tree) and Acer saccharinum (silver maple tree) seed oils

GC analysis was performed to determine regiospecific distribution and FA composition in seed oils of the Aceraceae species, Acer saccharum and A. saccharinum. The oil content in the seeds was low at 5.0% in A. saccharum and 5.8% in A. saccharinum, and the main FA were linoleic (30.8 and 29.4%), oleic (21.3 and 27.6%), palmitic (10.1 and 10.5%), and cis-vaccenic (9.4 and 7.9%) acids, respectively. In addition, both oils contained long-chain monoenes of the n−9 and n−7 groups, including 11-eicosenoic, 13-docosenoic, 15-tetracosenoic, 13-eicosenoic, and 15-docosenoic acids, whereas γ-linolenic acid accounted for 0.8% of total FA in A. saccharum, and 0.5% in A. saccharinum. Regiospecific analysis, performed using the methodology of dibutyroyl derivatives of MAG, indicated that linoleic, oleic, and linolenic acids were mainly esterified at the internal position of TAG in both seed oils, whereas long-chain monoenes of the n−7 group were almost exclusively esterified on the external positions.     

用MapleSim进行多领域混合建模仿真分析

为了评估MapleSim建模与仿真软件性能。该文简要介绍了MapleSim及其特点并阐述了MapleSim进行建模分析的步骤。并实验用MapleSim对一个机械系统和模拟电路信号产生电路建模仿真和分析,比较不同实验情况结果和提取系统方程。结果表明MapleSim是一个优秀的、直观快捷的高性能多领域复杂系统物理建模仿真分析工具。实验有指导意义。     

工艺参数对硬枫薄木贴面杨木多层板表面质量的影响

以硬枫薄木和杨木多层板为材料,根据影响薄木饰面家具表面质量的工艺因素,对添加剂、涂胶量、热压压力、热压温度、热压时间5因素进行4水平的L16(45)正交试验,用平衡分析法对透胶率和翘曲度进行分析,得出最佳的贴面工艺。研究表明,单位压力与涂胶量是影响透胶率和翘曲度的最重要的因素,添加剂对透胶率影响较大而对翘曲度影响最小,热压温度和热压时间对透胶率和翘曲度的影响不明显。     

枫槭叶酶解液美拉德反应及其挥发性成分分析

为了开发新型食用香精,以枫槭叶为原料对枫槭叶酶解后的酶解液在不同温度下进行美拉德反应,然后使用GC-MS分析美拉德反应样品的挥发性成分,采用主成分分析法对挥发性成分进行分析,探讨不同温度下美拉德反应样品的差异及特征成分。结果表明：枫槭叶酶解液与枫槭叶水提取物进行美拉德反应后相比,挥发性物质的种类数和含量都有所增加。GC-MS分析结果表明：美拉德反应90℃的样品挥发性香味成分的种类最多,为67种,并且挥发性物质总含量最多,为235.9 μg/g。通过主成分分析可知美拉德反应90、100、110℃的样品彼此距离较远,说明其主成分差异均较大,90℃美拉德反应挥发性物质分布最多,3,4-二甲基-3-环己烯-1-甲醛、金合欢基丙酮、萜品烯、棕榈酸、丁香酚、左旋-beta-蒎烯、桃金娘烯醇、十二烷酸、2,2'-亚甲基双-（4-甲基-6-叔丁基苯酚）、甲基庚烯酮为枫槭挥发性成分的主要特征化合物。结合上述结果,在美拉德反应温度为90℃时得到的样品具有最佳的风味和感官品质。     

贴面工艺对硬枫薄木贴面家具板材翘曲度的影响

主要讨论了贴面工艺对杨木多层胶合板双面贴硬枫薄木的家具板材翘曲度的影响,采用正交实验法分析了涂胶量、热压压力、热压温度、热压时间四个因素对杨木多层胶合板双面贴硬枫薄木的家具板材翘曲度的影响.结果表明,涂胶量对板材翘曲度影响最显著,热压压力与热压时间对翘曲度也有一定影响.建立了涂胶量、热压压力、热压温度及热压时间四个因素和板材翘曲度之间的四元二次回归方程.     

用枫树高得率化机浆生产高档涂布纸板

在亚洲和欧洲，许多纸板是用多层纸板机抄造的。与单层成形相比，纸板多层成形具有灵活选择纤维原料的优势。多层纸板生产中，面层主要由漂白化学浆构成，而中间层和底层则可选用价格相对低廉的GW、TMP、高得率化机浆和二次纤维或多种不同种类纤维的混合。在上述纤维中，枫树高得率化机浆以其极高的松厚度独具优势。文章讨论了枫树高得率化机浆的特性及其在纸板生产中的应用。     

MODELING VACUUM-CONTACT DRYING OF WOOD: THE WATER POTENTIAL APPROACH

ABSTRACT

A two-dimensional mathematical model for vacuum-contact drying of wood is presented. The moisture and heat equations are based on the water potential concept whereas the pressure equation is formulated considering unsteady state conservation equation of dry air. Most of the model parameters were determined during independent experiments. The set of equations is then solved in a coupled form using the finite element method. The validation of the model is performed using experimental results obtained during vacuum-contact drying of sugar maple sapwood. The experimental and calculated data are in good agreement. Nevertheless, some discrepancies are observed which can be attributed to the boundary conditions used and to the fact that heat transfer by convection was neglected.     

Hot-Water Extraction Optimization of Sugar Maple (Acer saccharum Marsh.) and Red Maple (Acer rubrum L.) Bark Applying Principal Component Analysis

In the forest industry, bark is an abundant residue, predominantly converted into calorific energy. As the antioxidant potential of phenolic compounds from sugar maple (Acer saccharum Marsh.) and red maple (Acer rubrum L.) bark has previously been established, the present study focused on the hot-water extraction optimization of these barks. Several process parameters (maple species, temperature, duration, ratio bark/water, particle size) were thus studied and large disparities were found between the two species. Extraction yield, phenolic content, and antioxidant capacity of red maple extracts were several times higher than those of sugar maple extracts. Principal component analysis, applied to the selected best extraction conditions, identified 3–4 clusters depending on the maple species. These groups were sorted from the highest extraction yield and energy consumption combined with the lowest phenolic content and antioxidant capacity, to moderate extraction yield and energy consumption with the highest phenolic content and antioxidant capacity.