首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   33篇
  免费   5篇
工业技术   38篇
  2024年   1篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2015年   2篇
  2013年   6篇
  2012年   1篇
  2011年   2篇
  2010年   4篇
  2009年   4篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2002年   1篇
  2000年   1篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
排序方式: 共有38条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: Echinacea purpurea L. (EP) is a popular herbal antioxidant and immunomodulator. The present study was conducted to evaluate the effects of EP on meat quality and oxidative status in broilers. Two hundred and fifty (1‐day‐old) male broilers (Arbor Acres) were randomly allocated to five groups including the control (corn‐soybean meal diet) and 0.1, 0.5, 1.0 and 2.0% EP powder groups, with two replicates per treatment group. RESULTS: The results indicated that the addition of 0.5% and 1.0% EP significantly increased water‐holding capacity and decreased storage loss of breast and thigh fillets at 35 days old. For fillet colour, L* (lightness) values were lower, and a* (redness) and b* (yellowness) values were higher with EP supplementation. Lower crude fat contents were observed in EP groups in comparison with control at 35 days of age in breast and thigh fillets, respectively. Production of malondialdehyde was slightly reduced in serum of EP supplemented birds compared to the control group. Results for Trolox equivalent antioxidant capacity, catalase and superoxide dismutase were significantly higher for the 0.5, 1.0 and 2.0% EP supplemental groups than control group in serum. Liver and spleen tissues results showed that the antioxidative enzymes activities were higher with EP powder at 35 days of age. CONCLUSION: Dried EP can be used as a feed additive to improve the meat quality and oxidative status in Arbor Acres broilers. Copyright © 2012 Society of Chemical Industry  相似文献   
2.
The present study was conducted to develop subcritical water extraction (SWE) of Echinacea purpurea flowers. The influence of temperature and extraction time on quality of extracts considering total phenols content, total flavonoids content, antioxidant capacity and extraction yield, was determined. Optimized extraction parameters for maximised investigated responses were as follows: 147.56 °C and 8.43 min. The experimental values agreed with the values predicted, thus indicating the adequacy of central composite experimental design for modelling the SWE of bioactive compounds from E. purpurea. Results of the study also highlighted the potential application of E. purpurea subcritical water extracts as a source of valuable bioactive compounds.  相似文献   
3.
在优化Folin-Ciocalteau法测定多酚比色条件及单因素实验的基础上,采用Design-Expert软件中的中心复合设计(Central Composite Design,CCD)模块,设计一组3因素实验来确定超声波功率、料液比和提取时间这3个因素对从红菜苔茎皮等废弃物中提取多酚的影响。构建了具有良好预测能力的数学模型并通过响应曲面分析得到了红菜苔多酚最佳提取参数:超声波功率249W,料液比52∶1(mL∶g),提取时间34min,在此条件下进行验证实验,测得红菜苔多酚提取量为5.84mg/g,达到理论预测值的97.34%。采用该工艺条件提取红菜苔多酚,稳定可靠,得率较高,无污染,可用于指导红菜苔废弃物中多酚的提取生产。   相似文献   
4.
《食品工业科技》2013,(07):52-55
以过氧化值、酸值及TBA值为指标,以菜籽油和猪油为介质,并与人工合成抗氧化剂BHT和BHA进行对照,研究了紫花松果菊挥发油对菜籽油和猪油的抗氧化性能。结果表明:在所研究的浓度范围内,紫花松果菊挥发油对菜籽油和猪油均具有一定的抗氧化作用,且具有剂量效应关系。其中,添加量为2g/kg的紫花松果菊挥发油对菜籽油的抗氧化效果较为明显,几乎等效于0.2g/kgBHT和BHA的抗氧化作用。紫花松果菊挥发油对猪油的抗氧化效果则不及对菜籽油的抗氧化效果明显。   相似文献   
5.
This study was carried out to determine the antioxidant activity of phytochemicals and plant extracts in fresh lamb patties. Quality indices such as colour (Hunter L* a* b*), lipid oxidation (TBARS) and pH were measured over an 8‐day storage period. Resveratrol, citroflavan‐3‐ol, olive leaf extract and Echinacea purpurea were added to raw minced M. longissimus dorsi lamb patties, at concentrations ranging from 0–400 mg kg?1 lamb meat, stored in high oxygen modified atmospheres packs (75% O2:25% CO2) for up to 8 days at 4 °C. The pH of the lamb meat was not significantly affected by the addition of the phytochemicals and plant extracts examined (P > 0.05). Resveratrol and citroflavan‐3‐ol decreased (P < 0.05) lipid oxidation in raw lamb patties during storage and increased a* values (P < 0.05), relative to controls. By contrast, olive leaf extract and Echinacea purpurea did not exhibit antioxidant activity or promote higher a* values relative to controls. Results obtained demonstrate potential for the development of functional meats using plant extracts such as resveratrol and citroflavan‐3‐ol.  相似文献   
6.
Echinacea purpurea contains many beneficial constituents for protection of skin from oxidative stress and for improving hydration of skin. This study aimed to investigate the stability and dermatological efficacy of E. purpurea cream and gel. Echinacea purpurea extract was incorporated into suitable cream and gel bases. Stability of the extract in the formulations was investigated by determining its residual total phenolic content and antioxidant activity after storage at 4°C, 30°C and 40°C for 6 months. The effect of those formulations on skin irritation, hydration level and wrinkle reduction was evaluated in 10 healthy volunteers, aged 25–40 years. The shelf lives of E. purpurea cream and gel in terms of total phenolic content and antioxidant activity were only 2 and 4 months respectively at 4°C and could be extended up to 7 months by incorporation of α‐tocopherol or disodium editate. The corneometer hydration indices increased up to 10.6 AU and 11.4 AU, and the wrinkles decreased 9.47% and 14.92% because of the application of E. purpurea cream and gel for 1 month. Both formulations showed no irritation to skin. Echinacea purpurea cream and gel developed in this study were effective in improving skin hydration and reducing wrinkle, but showed low storage stability.  相似文献   
7.
Some nutritional and antinutritional characteristics and biological value of Bauhinia purpurea L seeds were studied. The mature seeds contained (g kg-1 as is) 271·7 crude protein, 58·7 crude fibre, 124·5 crude fat, 29·3 ash and 515·3 carbohydrates. Potassium, phosphorus and iron occurred in higher concentrations when compared with commonly consumed legumes. The globulins and albumins together constituted major storage proteins (82% total protein). The essential amino acid profile of total seed proteins compared well with the FAO/WHO reference pattern except for a deficiency of sulphur-containing amino acids and tryptophan. When compared with the globulins, the albumins appeared to be a rich source of cystine, methionine, threonine, lysine and tryptophan. Seed lipids contained high levels of the unsaturated fatty acids, oleic and linoleic, which accounted for 62·6% of total fatty acids recovered. Both dry heating and autoclaving significantly reduced the antinutritional compounds. The in vitro protein digestibilities of raw, dry-heated and autoclaved seeds were 59·5, 72·3 and 78·7%, respectively. True digestibility and net protein utilisation were significantly higher in processed seed samples compared with raw seeds. Regarding utilisable protein, autoclaved samples exhibited relatively higher values than raw seeds. © 1997 SCI.  相似文献   
8.
Free proline has multiple functions in plant cells, such as regulating osmotic potential and protecting both proteins and cell membranes. The expression of Δ1-Pyrroline-5-carboxylate synthase (P5CS), a key enzyme in the proline biosynthetic pathway, increases under drought, salt and cold stress conditions, causing plant cells to accumulate large amounts of proline. In this study, we cloned and identified the P5CS gene from Stipa purpurea, which has a full-length of 2196 bp and encodes 731 amino acids. A subcellular localization analysis indicated that SpP5CS localized to the cytoplasm. The ectopic overexpression of SpP5CS in Arabidopsis thaliana resulted in higher proline contents, longer roots, higher survival rates and less membrane damage under drought stress conditions compared with wild-type controls. SpP5CS-overexpressing A. thaliana was more resistant to drought stress than the wild type, whereas the deletion mutant sp5cs was less resistant to drought stress. Thus, SpP5CS may be a potential candidate target gene for increasing plant resistance to drought stress.  相似文献   
9.
Spondias purpurea L. is a fruit native to Mexico, however, it is found as far away as Brazil. It possesses a high commercial potential owing to its sensorial and nutritional qualities and its low cost of production. There exists a variety of ecotypes that have not been characterized and their adequate selection process, according to their strongest functional characteristics, will allow the establishment of improvement programs for this genetic resource. The object of this study was the chemical characterization and the determination of the in vitro and in vivo antioxidant capacity of 7 Spondias purpurea L. ecotypes. Differences were observed in the antioxidant capacity and the content of functional compounds among all the ecotypes analyzed. A high total phenolic content and a low flavonoid and carotenoid content were found, both in the epicarp and in the pulp. In each ecotype, the hydrophilic phase presented up to 40 times greater antioxidant capacity compared to the lipophilic phase. The hydrophilic phase of the epicarp of “Costeña Tierra Colorada” had the greatest antioxidant capacity and highest total phenolic content, whereas “Jocote” presented the lowest antioxidant capacity and total phenolic content. A positive correlation was observed between phenol levels and the antioxidant capacity in the epicarp. Regarding antioxidant activity in vivo, it was observed that in all analyzed concentrations of hydrophilic extracts of the epicarp of “Costeña Tierra Colorada” and in the highest “Jocote” concentrations, they provided thermo‐protection against heat stress as well as a general well‐being to the worm as evidenced by their high mobility.  相似文献   
10.
In this study, the effect of nitrogen form (nitrate and ammonium in the molar ratio of 1:1 or 1:0), supplied to the plant or NaCl salinity (up to a concentration of 50 mol m−3) of the feeding solution, on the content of selected caffeic acid derivatives and the activities of phenylalanine ammonia lyase (PAL; EC. 4.3.1.5) and shikimate dehydrogenase (SKDH; EC 1.1.1.25) were investigated in the leaves and the roots of Echinacea angustifolia DC, grown hydroponically. Two experiments were conducted under glasshouse conditions with seedlings transplanted in aerated stagnant nutrient solution (floating raft system) four weeks after emergence. The nitrate/ammonium ratio in the nutrient solution did not affect plant growth or dry matter partitioning, but it influenced the concentration of determined metabolites; in particular, the root concentrations of chlorogenic acid, echinacoside and caffeic acid were significantly higher in the plants grown with nitrate as sole source of nitrogen. NaCl salinity reduced plant growth, by reducing the biomass allocated to the inflorescences, and enhanced the accumulation of chlorogenic acid and cichoric acids, at least in the roots.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号