共查询到20条相似文献，搜索用时 62 毫秒
1.
《西安文理学院学报》2020,(1)
香菇多糖是一种从香菇中提取的有效活性成分,具有多种生物活性,广泛应用于各个行业,在食品行业中可作为天然防腐剂.采用超声波辅助热水浸提法,在料水比1∶15、超声时间10 min、浸泡时间1.5 h条件下提取香菇多糖,采用苯酚硫酸法绘制出葡萄糖的浓度与吸光度的标准曲线.通过紫外分光光度法研究香菇多糖对大肠杆茵的抑制性能,并探讨了香菇多糖的浓度对抑菌效果的影响.结果显示,随着香菇多糖浓度的增大其抑菌效果越好. 相似文献
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三种长白山野生食用菌多糖和微量元素含量测定 总被引：1，自引：0，他引：1
目的测定三种长白山野生食用菌—牛肝菌、密环菌、香菇的中多糖和微量元素的含量.方法采用水提醇沉法提取多糖,苯酚—硫酸法测定多糖含量,火焰原子吸收光谱法测定Ca、Fe、Zn、Mg四种微量元素的含量.结果牛肝菌、密环菌、香菇中多糖含量依次为7.67%、14.45%6、.92%.微量元素含量依次为（μg.g-1）：Fe：910.97,69.4,473.0,Ca：176.1,68.8,141.7;Mg：34.3,25.33,0.1;Zn：128.7,83.91,24.9.结论三种长白山野生食用菌均含有丰富的多糖和微量元素,其中密环菌多糖含量最高,牛肚菌微量元素含量最高. 相似文献
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以香菇多糖为研究对象,采用单因素分组实验法对香菇多糖提取工艺(热水法和微波提取法)进行了初步的探讨,比较了时间,浸取温度,浸取次数,液固比等因素对多糖提取率的影响。其中传统热水提取法的最佳工艺条件为:液固比10,加热温度45℃,加热时间5h,提取二次。微波法提取香菇多糖的最佳工艺条件:液固比10,功率40,加热时间180s,pH值1。通过两种最佳工艺条件的结果比较可知,微波萃取法具有节能、省时、环保、操作便利且提取率高等优点。 相似文献
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本文研究了黑糯玉米多糖的提取及两种脱蛋白分离工艺的比较.采用热水浸提、醇沉法提取黑糯玉米多糖,用两种改进的方法(氯仿-正丁醇法和三氯乙酸-正丁醇法)脱除蛋白质,以脱蛋白率为指标,通过正交实验L9(34)确定最佳脱蛋白分离工艺后,对比两种方法的最佳组合粗多糖得率及510nm处吸光值的差异.结果表明:三氯乙酸-正丁醇法比氯仿-正丁醇法的脱蛋白效果好,最佳水平脱蛋白率为70.69%,多糖得率仅为67.87%;氯仿-正丁醇法最佳水平脱蛋白率为51.39%,多糖得率为80.31%.本文建立的优化工艺可为黑糯玉米多糖的分离制备提供参考. 相似文献
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本研究主要从清除超氧阴离子自由基功能、清除羟自由基功能及抗DPPH自由基能力测试来评价香菇胞外多糖抗氧化功能。在浓度为0.30mg·m L-1条件下,香菇胞外多糖对羟自由基、DDPH自由基的清除率分别为76.23%和62.58%,而如果浓度为0.25mg·mL-1,香菇胞外多糖能将68.12%的超氧阴离子自由基清除。实验结论最终表明,其抗氧化能力比较突出。此外,对香菇胞外多糖的抑菌活性及其抑菌稳定性进行了研究。结果证实:酸碱度值如果处在5-9之间,香菇胞外多糖则全面存在着抑菌活性,其中最强抑菌活性发生在酸碱度值pH=6时。结果证实,该菌株的酸碱抑菌谱比较广。而且这种香菇胞外多糖的热稳定性能较好,121℃条件下30min处理,抑菌活性依然不会受到明显影响。香菇胞外多糖的生化特征良好,有效奠定了其未来的发展与应用基础。 相似文献
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《西安文理学院学报》2015,(3)
植物多糖因具有抗肿瘤、增强免疫力、降血糖等多种生物活性而广受关注与研究.提取分离是多糖领域研究的基础.综述了植物多糖提取分离的六种新型技术:酶法,超声波,微波,超临界萃取,膜分离以及色谱分离,分析了它们的作用原理、主要影响因素和应用,并探讨了发展前景. 相似文献
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香菇多糖几种提取方法的比较 总被引：6，自引：0，他引：6
本文通过对香菇多糖的热水浸提法,酸浸提法,复合酶浸提法,复合酶解、酸处理结合热水浸提法等几种提取方法进行了研究比较,实验结果表明：提取率高且浸提效果理想的方法是复合酶解、酸处理结合热水浸提法,此法能显著提高可溶于热水的多糖及还原性寡糖的浸提率,香菇多糖的浸提率达8．96％。同时,在单因素实验条件的基础上,针对复合酶解时溶液的pH值、复合酶解时间、热水浸提温度、热水浸提时间进行了四因素三水平的正交实验,并通过极差分析,确定了利用复合酶解、酸处理结合热水浸提法提取香菇多糖的最佳提取条件：复合酶解时溶液的pH值为5．0,复合酶解时间为80min,热水浸提温度为90℃,热水浸提时间为90min。 相似文献
8.
采用蛋白酶和纤维素酶两种复合酶处理,对酶液的用量(蛋白酶浓度为8%、纤维素酶为4%),料液比,最适pH值,反应时间进行单因子和正交试验.确定了复合酶法提取香菇多糖的最佳工艺为:料液比1∶25,pH值4.8,酶液量0.35ml(蛋白酶浓度为8%、纤维素酶为4%),反应时间1.5h,多糖提取率为15.13%,比起传统水提法有大幅提高. 相似文献
9.
玉米须多糖提取工艺的研究 总被引：1，自引：0，他引：1
本文对玉米须中水溶性多糖的提取工艺进行了研究,结果表明,玉米须多糖的最佳提取工艺为：料水比1∶30,在90℃提取2次,每次2h.在此条件下,100g玉米须可提取得到4.55g多糖,多糖的中性糖含量为41.33%. 相似文献
10.
香菇多糖抗疲劳的实验研究 总被引：7，自引：0，他引：7
研究了香菇多糖的抗疲劳作用．用离体实验测定香菇多糖对肌肉收缩时间的影响，在体实验测定肌糖原含量．通过差异与对照组相比较时，发现香菇多糖的抗疲劳作用并无显统计学意义． 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
19.
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献