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1.
抗坏血酸和谷胱甘肽在小麦幼苗冷激诱导抗冷性中的变化 总被引：2，自引：0，他引：2
以小麦幼苗为实验材料，研究冷激及冷胁追处理过程中的抗坏血酸和谷胱甘肽含量变化，结果显示冷激处理小麦幼苗可导致还原型抗坏血酸和还原型谷胱甘肽的含量比对照组高，而脱氢抗坏血酸和氧化型谷胱甘肽的含量比对照组低．表明冷激处理可以使小麦幼苗细胞内抗坏血酸库和谷胱甘肽库中还原状态的抗坏血酸和谷胱甘肽含量明显增加，以有效地清除低温胁追产生的活性氧的危害，从而提高小麦幼苗的抗冷性．说明抗坏血酸和谷胱甘肽参与冷激诱导抗冷性的过程中起重要作用。 相似文献
2.
研究了山楂酱加工工艺中抗坏血酸的变化规律、影响因素及控制技术。结果表明：在山楂酱加工工艺中,抗坏血酸损失最严重的工序为打浆工序,其次为切分和常压浓缩为工序,其它工序对抗坏血酸含量影响不大;山楂整果形态软化不会导致的抗坏血酸损失,并使抗坏血酸含量提高６．４５％～２３．４４％,以山楂果片形态软化则会导致严重的抗坏血酸损失。蒸汽软化的抗坏血酸保存率显著高于热水软化;高糖量有利于控制常压深缩时抗坏血酸损失 相似文献
3.
蔬菜低硝酸盐制剂对蔬菜品质影响的试验研究 总被引：2，自引：0，他引：2
徐岩 《连云港职业技术学院学报》2002,15(2):12-14,17
以盆栽试验方式研究了青菜和生菜在喷施不同配方的低硝酸盐制剂后蔬菜体内硝酸盐含量的变化。结果表明，喷施0.05%和0.1%的甲壳素对蔬菜体内硝酸盐有一定的降解作用；而采用甲壳素与抗坏血酸和钼混合后进行叶面喷施会使这种降解作用更加明显。三种物质（甲壳素、抗坏血酸、钼）的混合喷施对生菜生物量的干生增加有促进作用。 相似文献
4.
以"全自动电位滴定仪测定药片中的维生素C含量"为例设计了一个研究型的分析化学实验,讨论了离子强度和浓度对全自动电位滴定法测定抗坏血酸的影响.实验结果表明,离子强度对本实验的测定结果无影响,浓度在0.828～79.69 mmoL/L测定准确度高.采用全自动电位滴定法对维生素C片中的抗坏血酸进行了分析.结果表明,平行测定7次,抗坏血酸含量平均值为61.59%,相对标准偏差为1.15%.采用库仑滴定法进行对照实验,表明采用全自动电位滴定法测定抗坏血酸是一种快速、准确、灵敏的检测方法.该实验具有研究性和探索性,打破了以往实验多为验证性实验的局面. 相似文献
5.
研究在酸性条件下,血红色的硫氰酸铁在不同浓度的抗坏血酸作用下还原褪色,根据褪色程度,比色定量,从而测出抗坏血酸含量的方法．该分析方法操作简便、快速、灵敏度高,准确性好,适合于各类蔬菜中抗坏血酸含量的测定． 相似文献
6.
多菌灵、井冈霉素及其复配剂对水稻纹枯病菌的增效作用 总被引：3，自引：0，他引：3
采用菌丝生长速率法分别测定了多菌灵和井冈霉素及其复配剂对水稻纹枯病菌(Rhizoctonia Sola-ni)的毒力,并用W adley增效比率法评价2种杀菌剂的联合作用。试验结果表明,当多菌灵:井冈霉素按1:4,1:9的比例混配时,其协同作用比率分别为2.27和1.60,表现为增效作用。 相似文献
7.
《河南职业技术师范学院学报(职业教育版)》2020,(3)
以冬小麦百农207为材料,利用10%PEG6000模拟干旱胁迫,研究硝酸镧对干旱下小麦抗坏血酸和谷胱甘肽代谢的影响.结果表明:干旱显著提高了冬小麦幼苗MDA含量和膜透性,并显著降低了抗坏血酸和谷胱甘肽氧化还原状态,这说明干旱对冬小麦幼苗造成了过氧化伤害.外源不同浓度硝酸镧处理均显著提高了干旱下抗坏血酸和谷胱甘肽循环代谢酶APX和GR及合成代谢酶Gal LDH和γ-ECS活性,进而显著提高了抗氧化物质AsA和GSH含量以及抗坏血酸和谷胱甘肽氧化还原状态,从而显著降低了MDA含量和膜透性.除100μmol/L硝酸镧外,其他浓度的硝酸镧均显著提高了干旱下抗坏血酸和谷胱甘肽循环代谢酶DHAR和MDHAR活性,从而进一步提高了冬小麦抵御干旱的能力.研究结果表明,外源硝酸镧可以增强抗坏血酸和谷胱甘肽代谢合成和循环代谢,从而缓解干旱对冬小麦造成的过氧化伤害. 相似文献
8.
正确处理减轻中小学生过重课业负担、提高教学效率和提高教育质量三者之间的关系，是走出减负困局、实现增效提质的关键。只有真正减掉了中小学生过重的课业负担，才能倒逼教学增效，才能为学生全面发展腾出时间、空间，才能使学校教育真正走上以提高质量为核心的发展轨道。 相似文献
9.
鲜菊花保鲜工艺的研究 总被引：1，自引：0，他引：1
以综合感官评定为指标,通过单因素试验及正交优化实验,对包装方式、苯甲酸钠、抗坏血酸、氯化钙等因素对新鲜菊花的保鲜工艺进行了初步探索,经过研究发现,在用塑料托盘单层保鲜膜密封包装条件下,苯甲酸钠浓度为0.08%,抗坏血酸浓度为0.09%,氯化钙浓度为0.34%组成的保鲜液保藏菊花,菊花的保鲜效果最好. 相似文献
10.
全面落实“双减”政策,提高课堂教学质量是重要的突破口,智能技术赋能为其提供了新动能。为探索智能技术助力减负增效的实践路径,文章在分析当前教学实践中低效重负困境的基础上,对智能技术助力减负增效的价值进行了深入剖析。结合减负增效相关政策要求与技术应用,文章按照“以解决问题为导向、以课堂变革为核心、以技术赋能为动力”的理路,提出了智能技术助力教学减负增效的分析框架,包括总体目标、应用场景、技术服务、基础支撑4个层级和1个保障体系。文章最后聚焦智能技术在教学设计、教学实施、教学评价中的应用,详细阐述了智能技术对教学全流程减负增效的作用机理和典型的技术应用场景,为推进“双减”背景下技术支持的课堂教学变革、促进教学质量提升提供参考依据。 相似文献
11.
以DEAE-52离子交换柱层析和SephadexG-25凝胶过滤柱层析纯化米糠抗氧化肽,以硅胶G薄层层析测定其纯度,氨基酸自动分析仪测定其氨基酸组成。实验结果表明:米糠抗氧化肽经DEAE-52柱层析和Sephadex G-25柱层析后基本上得到了纯化;氨基酸组成分析表明,米糠抗氧化肽由14种氨基酸组成,富含两种酸性氨基酸:Asp、Glu,并含有6种人体必需氨基酸(Val、Met、Ile、Leu、Phe、Lys),占米糠抗氧化肽氨基酸总含量的31.89%,具有较高的营养价值和保健功能。 相似文献
12.
采用索氏提取法提取红车轴草种子中的脂溶性成分,进行甲酯化处理后用气相色谱-质谱联用技术（GC-MS）分离和鉴定脂溶性成分的组成和含量,同时运用N,N-二苯基三硝基苯肼自由基（DPPH）清除法和β-胡萝卜素漂白法对红车轴草种子脂溶性成分的抗氧化活性进行了初步研究.GC-MS法研究分析表明,红车轴草种子中共分离鉴定出6种脂溶性成分,包括亚油酸（29.64%）、（Z）-6-十八烯酸（14.60%）、棕榈酸（5.91%）、硬脂酸（3.24%）、三十烷酸（0.49%）和草酸葵基-丙基酯（0.17%）.抗氧化活性分析表明,红车轴草种子脂溶性成分对DPPH的自由基清除率IC50为17.97 mg/mL,0.04和0.08 mg/mL的β-胡萝卜素漂白法的抗氧化速率分别为29.9%和32.1%,均显著低于阳性对照BHT（96%）,说明红车轴草种子脂溶性成分的抗氧化活性较低.以上结果将对提取红车轴草种子脂溶性成分分析、提取分离和综合开发利用具有一定的参考价值. 相似文献
13.
Effect of chlorogenic acid on antioxidant activity of <Emphasis Type="Italic">Flos Lonicerae</Emphasis> extracts 总被引：7，自引：0，他引：7
Wu L 《Journal of Zhejiang University. Science. B》2007,8(9):673-679
Flos Lonicerae is a medically useful traditional Chinese medicine herb. However, little is known about the antioxidant properties ofFlos Lonicerae extracts. Here the antioxidant capacity of water, methanolic and ethanolic extracts prepared from Flos Lonicerae to scavenge 1,1-diphenyl-2-picrylhydrazyl （DPPH） radical and reduce Fe^3＋ to Fe^2＋ is examined. Chlorogenic acid, a major component of Flos Lonicerae, is identified and further purified from 70% ethanolic extract with high performance liquid chromatography （HPLC） and its antioxidant capacity is characterized. The total phenolic compounds and chlorogenic acid contents in Flos Lonicerae are determined. The present results demonstrate that the Flos Lonicerae extracts exhibit antioxidant activity and chlorogenic acid is a major contributor to this activity. 相似文献
14.
Survey of antioxidant capacity and phenolic composition of blueberry, blackberry, and strawberry in Nanjing 总被引：1，自引：0，他引：1
Wu-yang Huang Hong-cheng Zhang Wen-xu Liu Chun-yang Li 《Journal of Zhejiang University. Science. B》2012,13(2):94-102
Berries are a good source of natural antioxidants. In the present study, the total antioxidant capacity and phenolic composition
of three berry fruits (blueberry, blackberry, and strawberry) cultivated in Nanjing were investigated. Blueberry, with a Trolox
equivalent antioxidant capacity (TEAC) value of 14.98 mmol Trolox/100 g dry weight (DW), exhibited the strongest total antioxidant
capacity using both the 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and the 2,2-diphenyl-1-picrylhydrazyl
(DPPH) methods. Blueberry also had the highest total phenolic content (TPC, 9.44 mg gallic acid/g DW), total flavonoid content
(TFC, 36.08 mg rutin/g DW), and total anthocyanidin content (TAC, 24.38 mg catechin/g DW). A preliminary analysis using high
performance liquid chromatography (HPLC) showed that the blueberry, blackberry, and strawberry samples tested contained a
range of phenolic acids (including gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, ellagic acid, and cinnamic acid) and various types of flavonoids (flavone: luteolin; flavonols:
rutin, myricetin, quercetrin, and quercetin; flavanols: gallocatechin, epigallocatechin, catechin, and catechin gallate; anthocyanidins:
malvidin-3-galactoside, malvidin-3-glucoside, and cyanidin). In particular, the blueberries had high levels of proanthocyanidins
and anthocyanidins, which might be responsible for their strong antioxidant activities. These results indicate a potential
market role for berries (especially blueberries) as a functional food ingredient or nutraceutical. 相似文献
15.
16.
以茶叶籽为原料,采用超临界CO2萃取得到茶叶籽油,通过分子蒸馏富集提取茶叶籽油中抗氧化成分,并采用UHPLC-TOF-MS分析其组成。结果表明,CO2流速对萃取速率影响较大,采用超临界CO2梯度萃取的模式,不同萃取阶段得到的茶叶籽油的酸价存在一定规律,在萃取初期,茶叶籽油的酸价较高,随着萃取过程的进行,酸价逐渐降低,说明游离脂肪酸更容易溶解在超临界CO2中。茶叶籽油分子蒸馏馏出物中主要的抗氧化成分包括：山茶甙C,表儿茶素没食子酸酯,表阿福豆素,表儿茶素及表没食子儿茶素等5种。 相似文献
17.
Three cooking methods, namely boiling, steaming, and stir-frying for 5 to 10 min, were used to evaluate the effect on nutrient
components, free amino acids, l-ascorbic acid, total phenolic contents, and antioxidant capacities of bamboo shoots (Phyllostachys praecox). Results showed that boiling and stir-frying had a great effect on the nutrient components and they decreased the contents
of protein, soluble sugar, and ash, and caused a great loss in the total free amino acids (decreased by 38.35% and 34.86%,
respectively). Significant differences (P<0.05) in free amino acids were observed in the samples cooked by different methods. Stir-fried bamboo shoots had a high fat
content which increased by 528.57% because of the addition of edible oil. After boiling, the L-ascorbic acid and total phenolic
contents were significantly reduced, while steaming increased total phenolic content by 3.98% and stir-frying well-preserved
L-ascorbic acid (78.87% of its previous content). Results of the antioxidative property study showed that stir-frying could
increase antioxidant capacities of bamboo shoots. It is concluded that stir-frying is more suitable for bamboo shoots because
it could obtain the maximum retention of antioxidant capacities. 相似文献
18.
钱和 《浙江大学学报(A卷英文版)》2004,5(6)
Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 (15.5 and 511.6(6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH˙) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH˙ color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration (TEC90) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants. 相似文献
19.
Yun Xing Le Cai Tian-peng Yin Yang Chen Jing Yu Ya-rong Wang Zhong-tao Ding 《Journal of Zhejiang University. Science. B》2016,17(5):391-398
The antioxidant activities and total phenolic content of fermented Salvia miltiorrhiza with fungus Geomyces luteus were investigated. The results revealed that G. luteus fermentation could significantly improve the antioxidant activity and total phenolic content of S. miltiorrhiza. The main antioxidant constituents were characterized by spectroscopic analysis as salvianolic acids. High-performance liquid chromatography (HPLC) quantification also showed the enhanced content of salvianolic acid B after fermentation. The present study suggests that G. luteus fermentations are effective in the S. miltiorrhiza salvianolic acids’ enrichment process. 相似文献
20.
In order to investigate the antioxidant properties of the polysaccharides from the brown alga Sargassum fusiforme, the crude polysaccharides from S.fusiforme (SFPS) were extracted in hot water, and the lipid peroxidation inhibition assay exhibited that SFPS possessed a potential antioxidant activity. Hence, two purely polymeric fractions, SFPS-1 and SFPS-2 were isolated by the column of DEAE (2-diethylaminoethanol)-Sepharose Fast Flow, with their molecular weights of 51.4 and 30.3 kDa determined by high performance gel permeation chromatography (HPGPC). They were preliminarily characterized using chemical analysis in combination of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and found to contain large amounts of uronic acids and β-glycosidical linkages. The antioxidant activities of these two SFPS fractions were evaluated using superoxide and hydroxyl radical-scavenging assays. The results show that the antioxidant ability of SFPS-2 was higher than that of SFPS-1, probably correlating with the molecular weight and uronic acid content. 相似文献