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1.
以天宝岩长苞铁杉林内倒木为研究对象,结合以负荷量和含水率为自变量的综合燃烧属性及以灰分、热值、含水率及氮含量等理化性质为评价指标的燃烧熵值,综合探讨长苞铁杉林内倒木的燃烧性.结果表明,天宝岩长苞铁杉林内倒木属于低燃烧性可燃物,其发生火灾的可能性较小;长苞铁杉+糙花少穗竹混交林内倒木的燃烧性最低,非防火期长苞铁杉+毛竹混交林内倒木的燃烧性最大;倒木负荷量、综合燃烧属性值及发生火灾的可能性随腐烂等级升高而降低,平均含水率随腐烂等级增加而升高,燃烧性熵值随腐烂等级升高而降低.  相似文献   

2.
大孔树脂纯化山竹壳原花青素的研究   总被引:1,自引:0,他引:1  
研究比较了10种大孔吸附树脂对山竹壳原花青素的吸附和解吸性能,筛选出最适的大孔吸附树脂,并对该树脂的静态和动态吸附条件进行研究.结果表明,大孔吸附树脂XDA-7对山竹壳原花青素有很好的吸附和解吸性能,最佳吸附和解吸条件为:吸附流速为2 BV/h,解吸液乙醇浓度为60%,解吸流速为2 BV/h,解吸液体积为6 BV.得到纯化的原花青素纯度为66.20%.  相似文献   

3.
目的:研究大孔树脂纯化抱茎苦荬菜总黄酮的工艺。方法:对影响XAD-16型树脂纯化工艺的各项因素进行分析。结果上样液浓度3mg/ml,样液pH为4,最大上样量为14.25 mg/g,以2BV/h吸附速率进行吸附,用6BV的80%乙醇以1BV/h的流速进行洗脱,经XAD-16型大孔吸附树脂纯化后的抱茎苦荬菜总黄酮纯度达89.1%,得率为49.78%。结论:优化后的各项参数条件下,XAD-16型大孔吸附树脂对抱茎苦荬菜总黄酮有良好的纯化效果。  相似文献   

4.
为研究大孔树脂对状元豆黄酮的纯化工艺条件和效果,以状元豆黄酮粗提液为原料,吸附率和解吸率为评价指标,比较6种不同树脂对状元豆黄酮的静态吸附和解吸性能,筛选出AB-8树脂进行分离状元豆黄酮,并考察了纯化前后状元豆黄酮对食用油脂(猪油和花生油)的抗氧化效果。结果表明:最佳工艺条件为上样质量浓度4.0 mg/m L,上样流速3.0 BV/h,上样体积140 m L,用60 m L 65%体积分数乙醇溶液(p H6.0)为洗脱剂,以2.0 BV/h流速洗脱,得到AB-8树脂对状元豆黄酮的吸附率和解吸率分别为93.06%和95.12%,回收率为89.04%,得率为52.46%,纯度提高了约2.91倍。状元豆黄酮对油脂有一定的抗氧化效果,对猪油氧化抑制效果好于花生油,且纯化后抗氧化效果明显增强,是一种潜在的天然抗氧化剂资源。  相似文献   

5.
建立并优化猴耳环多酚的纯化工艺并对其组分进行定性分析。本研究以猴耳环多酚粗提物为原料,以吸附及解吸附效果筛选了最优大孔树脂,再以吸附、解吸附和纯度为评价指标,考察各工艺参数对AB-8树脂纯化多酚的影响,最后采用超高效液相色谱-四级杆-飞行时间串联质谱(UPLC-Q-TOF-MS)法进行多酚组成定性分析。结果表明:优选 AB-8树脂,粗提物以质量浓度3 mg/mL、流速1 mL/min上样10 BV(柱体积:1 BV=10 mL),水洗后,用60%乙醇5 BV以1 mL/min的流速洗脱。在此工艺条件下,多酚纯度达到58.64%。UPLC-Q-TOF-MS定性分析了纯化后猴耳环多酚14种组分。建立的猴耳环多酚的纯化工艺稳定可行,实现了其组分定性分析,为进一步研究提供了依据。  相似文献   

6.
利用聚酰胺树脂分离纯化马铃薯皮中的总黄酮,通过静态吸附试验和动态吸附试验研究了各因素对黄酮类物质的吸附及解吸附影响。结果表明,静态洗脱过程中,调节pH值为6左右,温度为30℃左右,振荡4 h后静置24 h,并采用浓度为70%乙醇作为洗脱液,即能获得最佳工艺;采用20 g聚酰胺树脂装层析柱的动态洗脱过程中,径高比为2.0/10.0(cm/cm),以70%乙醇作为洗脱液,即能获得动态的最佳工艺。  相似文献   

7.
8.
先用聚醚砜有机膜对豆粕乙醇提取液进行超滤,然后用D101大孔树脂纯化,研究大豆异黄酮的精制工艺.结果表明:用孔径5000D的有机膜超滤处理豆粕乙醇提取液,能够去除其中56.1%的杂质.用D101大孔树脂纯化,采用上样液浓度为0.750 mg·mL -1大豆异黄酮溶液,流速为1.0 BV·h-1,依次用去离子水、1.0 ...  相似文献   

9.
为了研究大孔树脂对水仙茶饼多酚的纯化效果,试验以水仙茶饼多酚粗提液为原料,比较了9种不同型号大孔树脂对水仙茶饼粗多酚的静态吸附和解吸性能,再以吸附率和解吸率为指标通过静态、动态吸附解吸试验。考察了各因素对LX-28树脂纯化水仙饼茶粗多酚的影响,最后探讨了纯化前后的水仙茶饼多酚的体外抗氧化和抑菌效果。结果表明:最佳纯化树脂LX-28,最佳吸附和解吸条件为1.5 mg/mL的质量浓度的水仙茶饼多酚粗提取液(pH4.0~5.0)以2.0 mL/min的流速上样95 mL,吸附平衡后去离子水冲洗至无色,再用70 mL,65%体积分数乙醇溶液(pH6.0)为洗脱剂,以3.0 mL/min流速洗脱,在此纯化条件下LX-28树脂对水仙茶饼多酚的吸附率和解吸率分别为(93.587±0.379)%和(95.330±1.282)%,树脂可重复使用4次,纯度提高了约3.04倍;对DPPH·和ABTS+·自由基清除率的IC50值分别从纯化前的1.279、3.682 mg/mL降低到0.295、1.525 mg/mL;对供试的大肠杆菌、金黄色葡萄球菌、米根霉和紫红曲霉均有不同程度的抑制作用,纯化后的水仙茶饼多酚的抑菌效果优于纯化前。  相似文献   

10.
目的优化大孔吸附树脂法纯化黄花草木樨叶中总皂苷的工艺。方法:以黄花草木樨中总皂苷的含量为指标,考察了5种大孔吸附树脂对黄花草木樨中总皂苷的吸附及解吸效果,筛选出最适皂苷纯化的树脂,并对纯化工艺进行了优化。结果:AB-8大孔吸附树脂适合纯化黄花草木樨中的总皂苷,最佳洗脱条件为:上样浓度为1.0mg/ml,上柱吸附流速为2.0ml·min^-1,以70%乙醇洗脱,洗脱流速2.0ml·min^-1,洗脱体积为5BV。结论所选工艺方法简便,稳定,纯化效果好。  相似文献   

11.
吸附茶多酚树脂的筛选   总被引:24,自引:0,他引:24  
徐向群  陈瑞锋 《茶叶科学》1995,15(2):137-140
通过对4种离子交换树脂和16种吸附树脂对茶多酚的交换或吸附及解吸性能的研究表明,92─2和92─3吸附树脂对茶多酚有较强的吸附能力和较好解吸性能,优于AmberliteXAD─7和日本HP─21。经这两种树脂静态吸附后,其提取物的茶多酚含量均可达60%左右(对照仅为26.6%,用日本《茶分析法》修改法测定结果)。表明这两种树脂适于从茶叶中制取高纯度茶多酚制品的工艺要求。  相似文献   

12.
树脂及活性碳吸附技术回收大豆乳清中的异黄酮和低聚糖   总被引:6,自引:0,他引:6  
对用树脂及活性碳吸附方法回收大豆乳清废水中的大豆异黄酮和低聚糖进行了研究。测定了树脂及活性碳吸附饱和曲线,研究了异黄酮和低聚糖的洗脱条件,建立了该法处理大豆乳清废水回收大豆异黄酮和精制大豆低聚糖的工艺。结果表明:处理1t废水,约可回收40%的大豆异黄酮130g,精制大豆低聚糖浆9kg,并将乳清废水的COD和BOD分别由13600和7800降至960和340。本法处理乳清废水可创造良好的经济效益。  相似文献   

13.
油茶粕中茶皂素纯化方法与抗菌活性研究   总被引:2,自引:0,他引:2  
对Amberliter XAD-16和DM130大孔树脂纯化油茶皂素的条件进行探索,比较两种树脂纯化的油茶皂素和AB-8大孔树脂纯化产品的纯度,并测定纯化产品与粗提物的抗菌效果。结果表明,在相应的最佳条件下,Amberliter XAD-16纯化所得的茶皂素产品纯度低,为74.5%;DM130大孔树脂处理的高,为 85.6%;AB-8大孔树脂居中,为83.5%。油茶皂素的粗提物和纯化物对供试微生物的抗菌效果一致,纯化物抑制程度略高;二者均对玉米纹枯病菌抑制效果最明显,对白色葡萄球菌、白色念珠菌和腊状芽孢杆菌的抑菌效果次之,对温和气单胞菌、豚鼠气单胞菌、嗜水气单胞菌、变形杆菌的抑制效果不明显,对黑曲霉、米曲霉的生长没有抑制作用。 茶皂素;油茶;大孔树脂;抗菌性  相似文献   

14.
Ethanol production from mixtures of sweet stem sorghum juice and sorghum grain was investigated under normal and very high gravity (VHG) fermentation conditions. Fermentation was carried out using Saccharomyces cerevisiae yeast strain N96 at 30°C. For VHG fermentation, sucrose was added to the sweet sorghum juice to obtain a concentration of 34 g per 100 ml of dissolved solids. Fermentation was carried out for 96 h using malted and unmalted milled sorghum grain from sorghum cultivars DC-75 and SV-2. Under VHG conditions, maximum ethanol levels were about 16.8% (v/v) and 11% (v/v) for media containing malted and unmalted milled sorghum grain, respectively. Although fermentation did not occur to completion, levels of ethanol obtained under VHG conditions were three times higher than the levels obtained under normal fermentation conditions. Under VHG conditions, about 8 g/100 ml of dissolved solids remained in the fermentation media after ethanol production had ceased while under normal fermentation conditions, about 4 g/100 ml of dissolved solids remained unused in the fermentation media. There was an initial decline in free amino nitrogen (FAN) levels up to 34 h followed by an increase up to 96 h under VHG fermentation conditions. Levels of assayable proanthocyanidins (PAs) from sorghum cultivar DC-75 were reduced during fermentation.  相似文献   

15.
以粗酯型儿茶素为原料,研究采用大孔吸附树脂和结晶纯化儿茶素单体EGCG的制备工艺。通过比较4种大孔吸附树脂对EGCG的吸附和解吸能力,筛选出最优树脂AB-8,并考察乙醇梯度洗脱等特性,再经过结晶析出EGCG晶体。结果表明:AB-8大孔吸附树脂对EGCG具有较好的吸附选择性,通过10%乙醇洗脱,EGCG产品纯度从54.41%提高到了92.65%,得率达93.38%,结晶后得纯度达98%以上的EGCG单体。  相似文献   

16.
Solid-phase extraction embedded dialysis (SPEED technology) is an innovative procedure developed to physically separate in-situ, during the cultivation, the mycelium of filament forming microorganisms, such as actinomycetes and fungi, and the XAD-16 resin used to trap the secreted specialized metabolites. SPEED consists of an external nylon cloth and an internal dialysis tube containing the XAD resin. The dialysis barrier selects the molecular weight of the trapped compounds, and prevents the aggregation of biomass or macromolecules on the XAD beads. The external nylon promotes the formation of a microbial biofilm, making SPEED a biofilm supported cultivation process. SPEED technology was applied to the marine Streptomyces albidoflavus 19-S21, isolated from a core of a submerged Kopara sampled at 20 m from the border of a saltwater pond. The chemical space of this strain was investigated effectively using a dereplication strategy based on molecular networking and in-depth chemical analysis. The results highlight the impact of culture support on the molecular profile of Streptomyces albidoflavus 19-S21 secondary metabolites.  相似文献   

17.
本文采用酶法预处理结合超声波辅助提取的方式,最大程度地提高了花生壳总黄酮的得率,并优化大孔树脂纯化工艺,提高了有效成分的纯度。花生壳黄酮的最佳提取工艺为:花生壳粉与水混合,半纤维素酶与木聚糖酶按1:1(m/m)复配,用量0.25‰,50℃酶解30 min后,按料液比1:20(m/V)加入乙醇至终浓度60%,于功率1000 W,55℃超声波辅助提取60 min,花生壳总黄酮的得率约为2.5%。选用D101型大孔树脂,上样缓冲液为pH 5.0的60%乙醇溶液,洗脱液为pH 10.0的70% 乙醇溶液,上样与洗脱流速为0.75 BV/h和1.5 BV/h。纯化后的花生壳总黄酮和木犀草素的纯度分别为10.54%和5.85%,提高了90%和120%。  相似文献   

18.
Bitterness reduction, especially of foods and beverages containing phytonutrients, is one of the biggest challenges in the food industry because bitterness has a deleterious effect on the taste profile of foods and beverages. Neem (Azadirachta indica A. Juss) is a medicinal tree, indigenous to the Indian-subcontinent, whose medicinal properties have led to it being heralded as the tree which is the “panacea for all diseases”. However, neem leaf is extremely bitter, in large part due to its limonoid content, making it unpalatable. The objective of this study was to apply two adsorbent based strategies, namely solid phase extraction (SPE) and Amberlite XAD-16 (AMB) resin, to achieve de-bittering of neem tea and to determine the effects of the de-bittering on the bio-active, color and volatile properties. The solid SPE treatment completely removed the flavonol, quercetin, from neem tea while in Amberlite XAD-16 treated tea (AMB) it was only insignificantly (p > 0.05) reduced. We also observed decreases in total phenolic content and consequently anti-oxidant activities after de-bittering. A 62% mean reduction of limonoid aglycones indicated diminished levels of bitterness. The loss of phenolics lead to a visually appreciable color changes in the treated teas. The de-bittering also leads to a loss of sesquiterpenes, ketones and acids from neem tea. In conclusion, we found that while SPE cartridges were more efficient in removing bitterness, they caused a greater reduction in bio-active compounds than AMB XAD-16 resins, which may ultimately affect the health properties of neem tea.  相似文献   

19.
海洋青霉HN89菌株次生代谢产物抗菌活性的研究   总被引:1,自引:1,他引:0  
海洋青霉HN89菌株次生代谢产物的抗菌活性与发酵条件对抗生素产量影响的研究结果表明:海洋青霉HN89菌株的次生代谢产物对细菌、酵母、霉菌均有抑制作用;摇瓶发酵产生抗生素(HN89A)的最佳培养基成分为:玉米淀粉20g/L,黄豆粉2g/L,K2HPO41g/L,NaCl0.5g/L,MgSO4 0.5g/L,FeSO4·7H2O0.01g/L,蛋白胨1g/L,用海水配制的海带汁(W/V,2%)1L,最佳发酵条件为28℃下振荡培养(200r/min)96~108h。合适的温度刺激能促进HN89A的合成。   相似文献   

20.
The objective of this work was to study the feasibility of using phosphoric acid to hydrolyze the hemicellulosic fraction of olive tree pruning, as a step in the bioconversion process to produce ethanol. Milled olive tree pruning was submitted to hydrolysis at 90 °C by phosphoric acid in a concentration range 0.3–8N for 240 min. The hydrolysates were then fermented by Pachysolen tannophilus. The hydrolysis stage was evaluated by the evolution of glucose and reducing sugars generated and by the conversion of hemicellulose fraction. The main parameters determined in the fermentation were: maximum specific growth rate, specific substrate consumption rate, specific ethanol production rate and ethanol yield. The maximum ethanol yield (0.38 kg/kg, equivalent to 74.5% of the theoretical yield) was obtained when hydrolysing with 0.5N phosphoric acid. Hemicellulose conversion is however incomplete at these operational conditions. Higher acid concentrations lead to higher hydrolysis of hemicellulose, but the ethanol yields resulting from the fermentation are lower.  相似文献   

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