天然迷迭香抗氧化剂的研究进展

迷迭香(Rosmarinus officinalis L.)是唇形科迷迭香属植物,我国南方地区已有大量种植.迷迭香精油是传统的天然香料.从提取精油后的残渣中提取得到的迷迭香提取物,具有良好的抗氧化性能,是一种天然抗氧化剂.本文综述了国内外迷迭香栽培、迷迭香提取物的主要化学成分和生产工艺及其作为抗氧化剂在油脂和食品中的应用等研究.同时展望了迷迭香提取物在其它领域,特别是在医药等领域中的应用前景.     

HACCP在初榨橄榄油生产中的应用

1前言橄榄油(olive oil)是用适当的机械方法从油橄榄鲜果中提取出来的油脂,其脂肪酸比例合适,含有多种维生素及多种微量元素等天然营养物质,此外含有在人体中具有一定生理活性功能的游离醇和酚类抗氧化剂等,有独特芳香和美味,饮食上具有独特的烹饪特点,其被人体吸收率达93.4%,对人体具有多种保健功     

天然色素植物万寿菊丰产高效栽培模式

万寿菊(Tagetes erectaL·)是菊科万寿菊属1年生草本植物。其花瓣中提取的植物天然叶黄素是一种性能优异的抗氧化剂,具有抗癌作用;可预防人体因器官衰老而引起的一系列疾病;同时还可以作为食品、药品和化妆品的色素添加剂。目前国内外对从万寿菊中提取的叶黄素的需求量日益增大     

天然迷迭香抗氧化剂的研究进展

迷迭香(Rosmarinus of ficinalis L．)是唇形科迷迭香属植物．我国南方地区已有大量种植。迷迭香精油是传统的天然香料。从提取精油后的残渣中提取得到的迷迭香提取物．具有良好的抗氧化性能．是一种天然抗氧化剂。本综述了国内外迷迭香栽培、迷迭香提取物的主要化学成分和生产工艺及其作为抗氧化剂在油脂和食品中的应用等研究。同时展望了述迭香提取物在其它领域．特别是在医药等领域中的应用前景.     

纯天然β-胡萝卜素的提取方法

β-胡萝卜素主要存在于绿、橙、黄、红色蔬果中,是胡萝卜素中含量最大的一种,是一种强抗氧化剂,具有高效碎灭单线态氧和清除自由基的作用,与其它类抗氧化剂相比,胡萝卜素的活性更强大.胡萝卜素具有防癌、抗癌、抗衰老、防辐射,降低胆固醇、治疗心血管病的特点,而且能清除香烟和汽车废气中的有毒物质,活化免疫细胞.此外,胡萝卜素还是一种安全无毒的天然色素和食品添加剂,广泛地应用于食品着色、营养保健品,药品及饲料四大领域.因此,如何从富含胡萝卜素的胡萝卜、盐藻和甘薯等天然物种中提取胡萝卜素,直接关系到胡萝卜素的开发应用.     

野生鱼腥草黄酮类化合物清除DPPH自由基的作用

以六盘水本地野生鱼腥草为原料,70%乙醇作为提取介质,提取野生鱼腥草黄酮类化合物.以抗坏血酸(VC)和VE为对照品,采用DPPH法研究野生鱼腥草黄酮提取物对自由基的清除作用.结果表明,野生鱼腥草黄酮提取物具有较强的抗氧化作用,在其浓度为51.644g/mL时其清除率可达62.27%,显著高于相同浓度下的VC和VE的清除率.因此,野生鱼腥草黄酮提取物可作为一种天然抗氧化剂.     

黄伞及黄伞多糖体外抗氧化作用的研究

以黄伞为研究对象,采用顺磁共振波谱法,对黄伞子实体提取粗多糖、菌丝体提取粗多糖、胞外多糖、纯化子实体提取多糖以及子实体粉、菌丝体粉共6个样品的体外抗氧化作用进行了分析.结果表明:4种黄伞多糖及子实体、菌丝体均具有较好的抗超氧阴离子自由基、羟自由基的能力,且多糖对超氧阴离子自由基和羟自由基的清除作用与多糖质量浓度成线性关系,而多糖对羟自由基的清除作用要优于菌丝体粉和子实体粉.黄伞及其黄伞多糖抗氧化作用显著,可以作为一种新的天然抗氧化剂进一步研究和开发.     

茶儿茶素的提取及制备技术

茶儿茶素作为茶叶中的最主要的生物活性,因其在茶叶中含量高达15%以及茶叶资源十分丰富而受到国内外生物学家和医药学家的重视,设计茶儿茶素功效及应用基础的研究论文约300篇/年.随着自由基生物学、自由基医学研究的深入,自由基作为许多疑难病症的致病因子已逐渐被人们所接受,因而寻找高效、低毒的自由基清除剂及其药物的研发近年来非常活跃.另一方面,在人们崇尚天然及合成抗氧化剂逐渐被限量使用的今天,天然的自由基清除剂亦被称为抗氧化剂,可广泛地应用于食品的抗氧化和保鲜.茶儿茶素作为一种分子结构中具有多个酚羟基的天然化合物,不仅具有强的抗氧化性,还具有强的清除自由基、调节免疫力等多种生理功能,这已被诸多研究证实.遗憾的是,这些研究结果是以茶儿茶素为实验材料而获得,可迄今为止,还未见从茶叶中高效地分离制备茶儿茶素的实用方法报道,因而分离就成为将茶儿茶素研究成果转化为生产力的"瓶颈".     

卷烟清除自由基的天然添加剂的筛选及其效果评价

研究了用于卷烟滤嘴的天然抗氧化剂活性的评价方法,同时验证了多酚类、黄酮类等天然抗氧化剂去除自由基的能力。研究结果表明:确定的适合于在实验室进行的对抗氧化剂的评价方法:HPLC法,考虑抗氧化剂的性能。分析得到的适于直接添加到卷烟滤嘴中的天然抗氧化剂:TP98%、TP35%、SIF40%、SIF20%、GSH。这5种抗氧化剂在去除稳定的自由基DPPH时都有较好的效果。以水∶油=93∶7(质量比)的比例添加天然抗氧化剂,对油剂的乳化没有影响。对样品水溶液分析了温度对其去除率的影响。     

石榴保健功能的研究进展

石榴果实富含对人体有益的抗氧化剂和营养成分,具有极高的保健作用。作者综述了石榴对人体有益的抗氧化剂和功能成分,以及近几年来国内外对石榴及其加工产品在抗癌、抗心血管疾病、抗胃病、抗糖尿病等方面的研究进展,最后在石榴研究领域提出了建议,以期为我国石榴研究与产业化开发提供了理论依据,为进一步开发石榴种质资源提供参考。     

Genetic control of germination and the effects of accelerated aging in mountain hemlock seeds and its relevance to gene conservation

Genetic control of germination parameters and the effects of accelerated aging in mountain hemlock (Tsuga mertensiana [Bong.] Carr.) seeds were investigated using standard germination tests and simulated aging, respectively. Germination parameters were studied on seeds collected from individual trees from two natural populations (Sooke and San Juan) located on southern Vancouver Island, BC. Strong genetic control was confirmed by the high heritability estimates that ranged from 0.35 to 0.82 (stratified) and from 0.58 to 0.73 (unstratified) for Sooke and from 0.30 to 0.85 (stratified) and from 0.45 to 0.84 (unstratified) for San Juan. Simulated aging was conducted on eight seedlots collected from natural stands representing the species distribution in British Columbia. Stratified and unstratified seeds were aged at 100% RH and 37.5°C for 0 to 21 days at 3-day intervals. Seed aging accounted for the majority of variation which ranged from 97.61% to 99.86% of the total variation observed. Gradual loss of seed viability was observed over the aging treatments with a total loss of viability after aging for 12 days. Differential losses in viability among seedlots were maximum after aging for 6 days. Results are discussed in terms of the impact of long-term storage and the reliance on seed banks for ex-situ conservation of this species.     

中国山水画与园林自然审美价值关系初探

从中国古代有名的山水画入手,分析传统山水画中人与自然的关系,包括敬畏山水自然、人与山水自然亲近以及山水自然与人亲近三个层次,共同表示中国人心中理想的景观模式。在进一步探讨中国古代山水画与中国园林的关系的基础上,对中国现代人居环境建设提出指导建议。     

我国农垦胶工老龄化原因与影响

通过对我国农垦胶工老龄化问题的研究,提出对胶工老龄化的界定,阐述出现老龄化的四个原因及其影响,得出结论。     

Aging law of spruce wood

Abstract

Accelerated aging of spruce wood samples have been carried out by thermo-hydro (TH) treatments. These treatments were applied to accelerate the chemical reactions that take place during the natural aging of wood. In order to avoid dissimilar chemical reactions between the TH treatments and the natural aging, mild temperatures (between 100 and 150°C) have been selected at low relative humidity (RH). The mechanical properties of non-aged, natural aged and accelerated aged spruce wood have been compared. It is apparent that longitudinal Young's modulus of accelerated aged wood increase slightly at the beginning of the treatment and is followed by a reduction. Along the radial direction, Young's modulus remains almost unchanged. On the other hand the radial strength is severely reduced. From these results, the relative radial strength has been fitted on the chemical kinetic law. The rate constant of this law has been calculated and the treatment temperature and wood moisture content have been integrated. Finally this law has been extrapolated to standard climatic conditions in order to predict the loss of strength of old wood by knowing its age and its mean climate history of temperature and RH (ambiance condition).     

Effects of Ultra-drying on Vigor and Physiological characteristics of Hippophae rhamnoides Seeds

Studies of ultra-drying and accelerated aging on Hippophae rhamnoides seeds from the arid and semiarid areas of northwest China were conducted. The results showed that H. rhamnoides seeds had higher desiccation endurance. When seeds were desiccated to 26 g/kg, their germination percentage, vigor indices and enzyme activity could be retained. After 30-day accelerated aging, ultra-dried seeds had better anti-aging ability and storability compared to natural dried seeds, and the best choice for the MC of seed ...     

丘陵岗地人工防护林退化成因分析

以桃江县人工防护林为研究对象,分析了导致林地退化的主要原因,包括管护措施不到位、造林技术缺陷、自然灾害侵害、生理老化、环境污染等。针对退化原因,提出了相应的改造措施。     

内蒙古磴口县沙漠化人文驱动力研究

文章通过对地处后套绿洲西部磴口县沙漠化现状及危害进行研究,运用主成分分析法分析得出土地沙漠化的人文驱动机制为畜牧业发展水平、农业现代化水平和人口因素等三个方面,并提出相关沙漠化防治的对策和措施。为黄灌区土地资源的可持续利用及管理,改善农牧交错地区脆弱生态环境提供一定的科学依据。     

荒漠化监测与评价指标体系框架

根据荒漠化的定义以及荒漠化的特点,荒漠化监测与评价指标体系由4个部分组成,即压力指标、状态指标、影响指标和防治指标。压力指标描述的是对自然资源的状态带来影响并导致荒漠化发生的自然和人为驱动因素,用来对荒漠化发展趋势进行评估并进行荒漠化早期预警;状态指标描述的是土地生态系统的状态和特性,可以分为物理指标、化学指标和生物指标,它们分别描述土地生态系统的物理、化学和生物特性;影响指标用来评价荒漠化对人类及其环境带来的影响;防治指标用来评价防治荒漠化采取的行动和措施以及采取这些行动和措施带来的社会经济和自然条件的改善。     

两种割胶制度对NR硫化胶耐老化性能的影响

采用热空气老化箱常规法结合热重分析(TG)法、差示扫描量热(DSC)法及橡胶加工分析(RPA)法研究两种割胶制度对生胶(NR)硫化胶耐老化性能的影响,结果表明:s/2d/4+ET2.5%割制硫化胶的耐老化性能优于s/2d/3+ET4%割制硫化胶。     

Performance characterization of rigid polyurethane foam with refined alkali lignin and modified alkali lignin

The two kinds of rigid polyurethane (PU) foams were prepared with respectively adding the refined alkali lignin and alkali lignin modified by 3-chloro-1,2-epoxypropane to be instead of 15% of the polyether glycol in weight. The indexes of mechanical performance, apparent density, thermal stability and aging resistance were separately tested for the prepared PU foams. The results show that the mechanical property, thermal insulation and thermal stability for PU foam with modified alkali lignin are excellent among two kinds of PU foams and control samples. The additions of the refined alkali lignin and modified alkali lignin to PU foam have little effect on the natural aging or heat aging resistance except for decreasing hot alkali resistance apparently. Additionally, the thermal conductivity of modified alkali lignin PU foam is lowest among two kinds of PU foams and control samples. The alkali lignin PU foam modified by 3-chloro-1,2-epoxypropane could be applied in the heat preservation field.