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以杜鹃红山茶花辦为材料,对其花色色素提取条件及理化性质进行研究.结果表明,杜鹃红山茶花色色素提取的最佳条件为:20%的乙醇、料液比1:5、浸提温度30℃、浸提时间1h;杜鹃红山茶花色色素具光、热不稳定性,在低pH时稳定,微酸近中性时变色;色素抗氧化、还原能力差,对整合剂、苯甲酸钠敏感;葡萄糖、蔗糖对色素无明显影响,食盐、柠檬酸、维生素C具增色作用;金属离子Co2+,Cu2+,Mg2+,Ca2+,Zn2+,Mn2+,K+,Al3+,Sn2+等具增色作用,Fe2+,Fe3+,Pb2+影响色素稳定性. 相似文献
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以康仙花为原料,提取康仙花色素并对其理化性质进行了研究。实验结果证明极性溶剂乙醇、甲醇和水对康仙花有效成分具有很强的提取能力,其中乙醇-水溶液(60∶40,体积比)对于康仙花色素的提取能力最大;康仙花色素在220及260 nm处均存在极高的吸收峰值;在酸性条件下康仙花色素颜色为红色(pH值1～4),且随pH值增大而变浅;在碱性条件下康仙花色素颜色转变为黄绿色;在pH值为1,60℃以下时,康仙花乙醇提取物对光、热具有较好的稳定性;Cu2+、Fe3+离子的存在对康仙花提取物的颜色和稳定性有很大的影响;食品添加剂Vc会破坏康仙花色素的稳定性;此外,康仙花的抗还原能力强于其抗氧化能力。 相似文献
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《林业科学》2021,57(3)
【目的】分析巴里黄檀心材色素成分,探究色素的稳定性和抗氧化性,为充分利用巴里黄檀资源提供理论基础和技术支撑,为同类红木资源的高效利用提供参考。【方法】从巴里黄檀木制品加工废料(刨花)中提取色素,使用超高效液相色谱-串联四级杆-静电场轨道阱高分辨质谱(UPLC-Q-EXACTIVE-MS)法分离鉴定色素成分,对色素主要成分进行定量;探究p H、金属离子、温度和紫外光照对色素稳定性的影响;以抗坏血酸(Vc)为阳性对照,分析色素对DPPH自由基和ABTS自由基的清除能力。【结果】从巴里黄檀心材色素中鉴定出荭草素、葛根素、牡荆素、异鼠李素、天竺葵素、矢车菊素、高车前素、白杨素、黄豆黄素、蓟黄素、樱花素、柚皮苷、染料木素、锦葵素、香叶木素、美迪紫檀素、芒柄花黄素、高丽槐素和6-羟基黄酮共19种黄酮类化合物,其中芒柄花黄素相对含量为2.27%;色素在酸性条件下稳定性较好,在碱性条件下稳定性差,p H9后溶液出现沉淀;K~+、Na~+、Ba~(2+)、Ca~(2+)、Mg~(2+)对色素几乎无影响,Al~(3+)对色素有增色作用,Gr~(6+)、Cu~(2+)、Fe~(3+)使色素产生沉淀,破坏作用较大;色素高温加热2 h内稳定性较好,长时间高温加热对色素有增色作用;紫外光照射对色素有缓慢增色作用;色素对DPPH自由基和ABTS自由基具有一定清除能力。【结论】巴里黄檀心材色素为黄酮类色素;色素在酸性至中性环境下较为稳定,在碱性条件下不稳定,Gr~(6+)、Cu~(2+)、Fe~(3+)存在时不稳定,长时间高温加热和光照对色素稳定性影响较大;色素具有一定抗氧化能力。 相似文献
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水溶性茶绿色素的提取及性质研究 总被引：3，自引：2，他引：3
利用低档茶叶及其废弃物制取纯天然水溶性茶绿色素，并对该色素的性质、制备过程中的两个主要工序——皂化、铜代的最佳工艺条件进行了研究。结果表明：用1％NaOH在80℃水浴煮90min是叶绿素皂化的最佳条件；然后将溶液pH值调为3．0，在80℃水浴煮50min，可使铜代完全；由此法制得的水溶性茶绿色素在pH值为2．2—5．0时，稳定性较好，热及大多数金属离子对其影响较小，维生素C对其稳定性有一定保护作用，不失为一种优质的天然食用色素。 相似文献
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为了确定纳滤法浓缩红树莓色素的最佳工艺条件,以红树莓色素溶液为原料,选取截留分子量为300u的纳滤膜浓缩纯化红树莓色素。以红树莓色素浓缩度衡量纳滤效果。通过单因素试验确定了温度、压力、进料质量浓度、pH对纳滤效果的影响。在此基础上,以色素浓缩度为响应值,利用响应面优化法,通过部分因子试验和中心组合试验设计,对纳滤法浓缩红树莓色素的最佳工艺条件进行了研究。得到最优条件为,纳滤温度为30℃,压力为0．6MPa,进料花色苷质量浓度为10．94mg／L,pH为3．12,此时色素截留率为98．26％。动态试验显示,红树莓色素纳滤法浓缩后浓缩度可达3．996。因此,纳滤法浓缩纯化为红树莓色素提取后加工提供了便捷稳定可行的方法。 相似文献
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可食雀梅藤果实色素的提取及理化性质研究 总被引：1，自引：0，他引：1
采用0.1% HCl - 70%乙醇(体积分数)水溶液从可食的雀梅藤果实中提取食用色素,并对该色素的理化性质和稳定性进行了研究.结果表明:色素得率为8.2%,色素易溶于水、甲醇、乙醇等极性溶剂,其颜色随pH值变化而变化,pH值≤3时,其最大吸收波长为530nm,有较好的耐热、耐光性,但耐碱、耐氧化还原性能差,葡萄糖、蔗糖、柠檬酸、食盐、苯甲酸、Mg~(2 +)、Zn~(2 +)、K +、Ca~(2 +)、Na +均使其色微减, Al~(3 +)、Fe~(3 +)、Cu~(2 +)使其变色;初步急性毒性实验中小白鼠无异常表现. 相似文献
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研究了冬青卫矛种子色素的提取条件和理化性质。结果表明,丙酮是冬青卫矛种子色素较好的浸提剂;其最佳提取条件为:料液比1∶10(g∶mL),浸提温度35℃,浸提时间40min,提取率为6.8%。对色素理化性质研究表明:该色素是脂溶性的,对热、添加物、金属离子、还原剂稳定,对酸碱均有较好的稳定性,但耐阳光性、耐氧化性较差;它为类胡萝卜素的天然色素。 相似文献
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叶黄素酯和叶黄素稳定性的研究 总被引：12，自引：1，他引：12
研究光、热、酸、碱、金属离子、氧化剂和还原剂对叶黄素酯和叶黄素稳定性的影响。结果表明,光对叶黄素酯和叶黄素的稳定性影响很大,日光照射0.5h,二者的保存率仅为0.35%,而放置在暗处保存率基本不变;叶黄素酯和叶黄素对热较稳定,但随着温度的升高和加热时间的延长,保存率下降,降解速度加快;在相同的光、热条件下,叶黄素酯的稳定性优于叶黄素,叶黄素以与脂肪酸结合的形式存在,稳定性更强;强酸性条件对叶黄素酯和叶黄素有一定的破坏作用,而其在中性、碱性条件下较稳定;Fe3 、Fe2 、Cu2 对它们的破坏作用较强,保存率下降较多,而Zn2 、Mg2 、Ca2 、K 、Na 对它们基本无影响;氧化剂H2O2对其有轻微的破坏作用;还原剂Na2SO3对叶黄素酯和叶黄素影响不大,VC可以使它们降解,与VC共存叶黄素酯的降解程度比叶黄素大。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
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本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):472-479
Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken. 相似文献
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Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic
or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts
(stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea
(Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content
as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest
N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized
to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea,
largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for
N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant
components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N
released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures
were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality
components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in
the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols.
Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest
age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its
components are mixed. 相似文献
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A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste
disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization,
(2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two
pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea
(Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect
on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage
sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but
affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral
systems.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):166-178
This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes. 相似文献