共查询到19条相似文献，搜索用时 667 毫秒
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为了揭示陈年茯砖茶多酚类对老年人肠道菌群多样性及结构的影响,从陈放1年及7年的茯砖茶中提取、纯化茶多酚,将等量茶多酚的提取物分别加入含有65岁老年人的肠道菌群混合培养基中进行体外静态厌氧培养,在0βh、4βh、8βh、12βh及24βh时对7年陈茶多酚组（O组）、1年陈茶多酚组（N组）及空白组（B组）进行茶多酚和短链脂肪酸（SCFAs）的含量测定,并进行肠道菌群的高通量测序,对测序结果进行生物信息学分析。结果显示,7年陈茯砖茶的茶多酚类在与老年人肠道菌群的体外互作下,SCFAs的含量较对照组显著提高,老年人肠道菌群的丰度及多样性水平也有所提升。在4βh及12βh时,能明显降低埃希氏菌属（Escherichia）及γ-变形菌纲_B38（γ-Proteobacteria_B38）的相对丰度,同时提高拟杆菌属（Bacteroides）、双歧杆菌属（Bifidobacterium）及普拉梭菌属（Faecalibacterium）的相对丰度。研究表明,7年陈茯砖茶的茶多酚类比1年陈茯砖茶的茶多酚类更有益于改善老年人的肠道菌群结构,在老年人的营养保健方面更具潜在的价值。 相似文献
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茶树是多年生常绿叶用作物,其生理代谢受外界环境因素影响显著。氨基酸、咖啡碱、茶多酚等生化成分不仅赋予茶独特的风味品质和健康特性,而且是茶树抵抗生物和非生物胁迫的重要贡献者。代谢组学技术具有高通量、高灵敏度和系统性的特点,可以全面、准确、快速地对代谢物进行鉴定和量化。代谢组学技术的深入研究为茶树代谢物的进一步开发利用提供了技术平台。综述近年来代谢组学在茶树生理代谢（光合、呼吸和碳氮代谢）和主要品质生化成分代谢（类黄酮类、生物碱、氨基酸等）研究中的应用,并对今后代谢组学在茶学领域的应用作出了展望,以期为茶树种植管理、品种开发以及茶叶品质改良提供理论参考。 相似文献
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茶多酚对蛋鸡生产性能、脂类代谢及蛋品品质的影响 总被引：17，自引：0，他引：17
本研究进行了两次饲养试验。试验一选用225羽37周龄罗曼蛋鸡随机分为5个处理,在试验基础日粮中分别添加0%、0.05%、0.1%、0.2%、0.4%茶多酚（纯度40%）,试验期59天;试验二选用600羽51周龄罗曼蛋鸡随机分为4个处理,分别在试验基础日粮中添加0%、0.025%、0.055%、0.1%茶多酚（纯度40%）,试验为期8周。探讨了茶多酚对蛋鸡生产性能、脂类代谢、蛋品质量的影响。结果表明：（1）日粮中添加不同剂量茶多酚对蛋鸡产蛋率和饲料利用率有一定的改善,但未见随茶多酚添加水平的升高而提高的趋势。（2）日粮中添加0.1%茶多酚可提高蛋黄中VE58.99%、VA20.96%,添加0.025%茶多酚降低蛋黄中胆固醇35.28%,茶多酚对全蛋中含硫氨基酸有增高趋势,重金属指标符合无公害鸡蛋要求;产蛋后期日粮中添加0.025%~0.1%茶多酚可降低破软蛋率31.59%~47.09%。（3）日粮中添加0.4%茶多酚分别降低46周龄蛋鸡血清总胆固醇19.65%、甘油三酯19.99%、低密度脂蛋白7.69%,提高高密度脂蛋白45.35%;但添加0.025%~0.1%茶多酚对59周龄蛋鸡血脂指标未见显著影响。 相似文献
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为探究儿茶素对高脂饮食小鼠减肥作用及肠道菌群的影响，将小鼠随机分为对照组、模型组、儿茶素组（0.06%儿茶素+高脂饲料），各组连续喂养28周，记录小鼠体质量和摄食量，计算肝脏系数、体脂比和Lee’s指数，检测血脂指标，并采用HE染色观察小鼠肝脏病理变化，实时荧光定量PCR检测小鼠肠道菌群的相对表达量。研究结果显示，与对照组相比，模型组小鼠体质量、肝脏系数、体脂比和Lee’s指数明显增加，血脂指标总胆固醇（TC）、甘油三酯（TG）及低密度脂蛋白（LDL-C）水平明显高于对照组，高密度脂蛋白（HDL-C）水平明显降低（P<0.05）；与模型组相比，儿茶素组小鼠体质量、肝脏系数及Lee’s指数明显降低，血脂指标TG和LDL-C水平明显降低、HDL-C水平显著增加（P<0.05）。肝组织病理结果显示，儿茶素组小鼠与模型组相比能明显改善肝组织病变程度，减少肝损伤；肠道菌群结果显示，儿茶素组小鼠拟杆菌相对表达量明显高于模型组（P<0.05）。研究结果表明，儿茶素可显著减少小鼠摄食量、降低体质量、调节血脂水平、改善肝组织病变和肠道菌群紊乱，对于高脂饮食小鼠具有较好的减肥作用。 相似文献
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典型造型名优绿茶茶多酚浸出规律的研究 总被引：4，自引：0，他引：4
本文研究了冲泡时间与水温对不同典型造型名优绿茶茶汤中茶多酚浸出浓度与浸出速率的影响,结果表明,随着冲泡时间的延长与冲泡水温的升高,茶多酚的浸出浓度不断上升,浸出速率逐步降低;造型、冲泡水温、冲泡时间对茶汤中茶多酚的浸出浓度与浸出比率的影响达到了极显著水平.各造型名优绿茶茶多酚的浸出浓度与速率快慢顺序为:卷曲形(以碧螺春为代表)>针形(以雨花茶为代表)>直条形(以信阳毛尖为代表)>单芽形(以竹叶青为代表)>扁形(以西湖龙井为代表)>朵形(以黄山毛峰为代表). 相似文献
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茶多酚与绿原酸生物活性的比较研究 总被引：8，自引：4，他引：4
为了研究茶叶与金银花中主要药效成分茶多酚和绿原酸生物活性的差异,应用过氧化值测定法、分光光度法、最小抑菌浓度(MIC)测定法分别比较茶多酚和绿原酸的抗氧化性、自由基清除能力、体外抑菌活性;结果表明在6周的观测期内,浓度为100βµg/g和200βµg/g的茶多酚可将猪油的POV抑制在10βmeq/kg范围内,且抗氧化能力随浓度增加而增强,这与81％绿原酸有相似结果;20％绿原酸、81％绿原酸、95％茶多酚对DPPH和·OH的半数抑制浓度(IC50)分别为327、1β432、65、135、52βmg/L和1β908βmg/L;95％茶多酚对大肠杆菌和金黄色葡萄球菌的MIC分别为500βμg/g和250βμg/g,81％绿原酸和20％绿原酸相应值分别为500βμg/g、500βμg/g和500βμg/g、1β000βμg/g;研究结论为茶多酚（95%）在抗氧化性、清除DPPH能力及对金黄色葡萄球菌的抑菌效果方面都要强于绿原酸（81%）,在清除·OH能力上要弱于绿原酸,在食品、药品行业中茶多酚有望比绿原酸发挥更大的作用。 相似文献
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J. Miranda A. Lasa M. A. Bustamante I. Churruca E. Simon 《Plant foods for human nutrition (Dordrecht, Netherlands)》2014,69(2):182-187
The gluten-free (GF) products market represents one of the most prosperous markets in the field of food and beverages in the immediate future. Historically, counselling for celiac disease has focused on the absence of gluten in foods, however the nutritional quality of GF foodstuffs is an important aspect to consider. The aim of the present work was to compare the nutritional composition of the 206 GF rendered products most consumed in Spain, against the composition of 289 equivalent foods with gluten, and to make a comparison between the diet including GF products and the same diet with equivalent products with gluten in a 58 adult celiac population. The results of the present collaborative study pointed out differences in calorie, macronutrient, fiber, sodium, salt and cholesterol content between GF rendered and gluten-containing foodstuffs. Thus, calorie and nutrient intake in a GF diet is different when compared to its equivalent diet with gluten. Following a diet based on GF products could suppose a nutritional imbalance for celiac patients as well as for non-celiacs who follow a diet that includes many GF rendered foodstuffs. 相似文献
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Federico Morreale Donato Angelino Nicoletta Pellegrini 《Plant foods for human nutrition (Dordrecht, Netherlands)》2018,73(2):154-159
Gluten-free (GF) products are consumed both by individuals with celiac disease and by an increasing number of people with no specific medical needs. Although the technological quality of GF products has been recently improved, their nutritional quality is still scarcely addressed. Moreover, the few published studies report conflicting results, mostly because the information from product nutrition facts is the only considered factor. The aim of the present study was to develop a score-based method for the nutritional evaluation of 134 packaged Italian GF bakery products and to compare it with that of 162 matched gluten-containing (GC) food items. The score included the information from the nutrition facts and the presence/absence of some nutritionally relevant components in the ingredients list. Results indicated an overall low nutritional quality of the considered GF bakery products. Additionally, with the sole exception of GF bread substitutes, there was no difference in nutritional quality between GF and equivalent GC bakery products. Future research and development of GF bakery products may take advantage of this scoring method, as it may represent an easy approach to evaluate their nutritional quality. The present findings do not justify the consumption of packaged GF bakery products by people without any specific medical needs. 相似文献
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日粮中添加绿茶粉及茶多酚对罗曼蛋鸡脂质代谢的影响 总被引：2，自引：0，他引：2
选择18周龄罗曼蛋鸡为研究对象,1620只罗曼蛋鸡随机平均分成9组,每组3个水平,每个水平60只,饲养周期为98 d;对照组喂基础日粮,其他8组在日粮中添加2、4、6、8 g/kg的绿茶粉和0.5、1.0、1.5、2.0 g/kg的茶多酚,研究绿茶粉和茶多酚对罗曼蛋鸡的腿肌、胸肌、蛋及血液中胆固醇及甘油三酯的影响。经定期取样测定,结果表明,日粮中添加6、8 g/kg绿茶粉和1.5、2.0 g/kg茶多酚能降低蛋鸡机体组织和鸡蛋及血液中胆固醇和甘油三酯的含量,最大的降低趋势出现在添加后8~10周,茶多酚的效果略优于绿茶粉。本研究为开发绿茶粉在鸡饲料中的应用提供了理论基础。 相似文献
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Dietary fibres can play a significant role in GF bread development. Besides their well documented health benefits, dietary fibres can improve the texture, sensory characteristics and shelf life of baked products, due to their water binding capacity, gel forming ability, fat mimetic, textural and thickening effects. Dietary fibres from different sources are discussed in this paper and their role in GF products' making is analysed. The sources of fibres vary: flours, fruit and vegetable processing by-products, isolated ingredients, seeds or mixtures of all of these can be used. Fibres improve the structure and result in dense crumb porosity. Tasty products with soft crumb can be produced, and there are many perspectives in further products development. 相似文献
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The supplementation effects of maize fiber arabinoxylans (MFAX, 0%–6%), laccase (0–2 U/g flour) and water absorption level (90%–100%) on gluten-free (GF) batter rheology and bread quality were analyzed. From viscoamylograph analysis, lower starch amount in GF flour due to MFAX addition decreased peak viscosity and retrogradation. Surface response plots showed that laccase did not have significant effect on GF batter rheology and bread quality, whilst water was the most important variable. Higher levels of water absorption benefited bread texture. Higher water level (>100 mL/100 g flour) was needed in the experimental design to evaluate correctly the effect of 6% MFAX replacement on GF bread quality. Further analyses were carried in order to adjust water absorption of batters according to their consistency index (K ≈ 100 Pa sn), resulting an optimal water absorptions of 95%, 100% and 105% for control flour and flours supplemented with 3% or 6% MFAX, respectively. Thus, MFAX addition enhanced water-binding capacity of flour and yielded GF breads with higher specific volume and softer crumb texture. These quality parameters were best rated with 6% MFAX addition to flours. This research demonstrated the potential of MFAX to develop GF breads with improved quality, when optimal water level is used. 相似文献
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Up to now, most of the research available to improve gluten-free (GF) bread is based on substituting or imitating the gluten network. Slightly less attention is given to technological approaches that modify batter properties such as consistency. This review summarizes the most recent advances to improve GF bread quality, focusing on latest conventional ingredients (e.g. hydrocolloids) and new innovative approaches to replace the gluten-network (i.e., use of enzymes, alternative polymer network), but especially on novel technological approaches, such as high hydrostatic pressure, sourdough technology and non-conventional heating methods. In general, hydrocolloids are still the most studied and well-known additives to gluten-free products, followed by the use of crosslinking enzymes. Within the review, special focus is given to the application of arabinoxylans, which form a stable carbohydrate network in GF batters that may substitute gluten. However, it was seen that technological approaches provide better solutions for enhancing GF bread properties than the latter, especially when non-conventional baking alternatives are applied. From these, ohmic heating resulted the most promising approach to overcome bread quality issues, while remaining time and energy-efficient. 相似文献
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Shuiping Li Qing Lin Huajun Zhu Chong Cui Haijun Hou Tingting Lv Yanbo Li 《Fibers and Polymers》2016,17(2):282-288
Glass fiber, GF, which was first hydroxylated and silanized, was incorporated into epoxy resin modified with amino-terminated hyperbranched polymer (ATHBP) to obtain high performance composite. The effects of GFs content on the mechanical properties of composites were investigated, discussing the results from flexural, tensile, and impact tests. The composites revealed noticeable improvement in flexural strength, tensile strength as well as impact strength but slow decrease in elongation at break, compared to the epoxy/ATHBP thermoset. FESEM morphology results indicated the good compatibility between epoxy matrix and GF in the appearance of ATHBP and showed that the toughening mechanism was mainly attributed to the stress transfer mechanism. 相似文献