共查询到17条相似文献,搜索用时 62 毫秒
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膳食纤维降血脂作用及其机制的研究进展 总被引:2,自引:0,他引:2
综述了近年膳食纤维降脂作用及其机制的研究进展.膳食纤维能使血清中胆固醇、甘油三酯、低密度脂蛋白水平降低,高密度脂蛋白水平升高.其主要机制为通过减少膳食中胆固醇的吸收、影响机体中胆固醇的代谢、促进胆固醇的排泄等降低血浆中胆固醇水平;通过增加食物在肠道内的过渡时间、延缓胃排空、减缓或降低脂肪的吸收等机制降低血浆中甘油三酯水... 相似文献
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马铃薯膳食纤维的结构特征分析 总被引:4,自引:0,他引:4
用水蒸汽爆破和氧化法对马铃薯废渣(PR)进行处理,制备马铃薯膳食纤维(PDF),并用红外光谱法、扫描电镜、热重及化学分析等方法对膳食纤维进行表征。结果表明,经过一系列的物理与化学处理,马铃薯渣中的半乳聚糖在蒸汽爆破下由长链断成短链,且由原来的块状变成片状、无规则的空间网层结构,断链的半乳糖醛基在氧化作用下生成羧基;所得到的PDF具有比表面积大、热力学稳定等特点。研究了PDF对胆固醇吸附性能。结果表明PDF对胆固醇的吸附量为1.4mg/g左右,其吸附机理符合Freundlich模式。马铃薯膳食纤维在生物体内对致病物质有一定的吸附作用。 相似文献
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通过抽样调查,了解重庆市环境缺碘地区居民的饮食习惯,分析了膳食因素对人群尿碘水平的影响,为制订地方性碘缺乏病综合防治措施提供依据.采用24 h膳食回顾法,对重庆市两县居民的膳食摄人情况进行现况调查,比较各营养素摄入量.结果表明,两地膳食结构属于东方膳食模式,璧山县各营养素摄入量高于云阳县.结论:蛋白质、能量、维生素等缺... 相似文献
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采用二维编织技术将聚丙烯腈(PAN)长丝编织成中空纤维编织管作为增强体,分别以聚丙烯腈(PAN)和聚偏氟乙烯(PVDF)为成膜聚合物,N,N-二甲基乙酰胺(DMAc)为溶剂,聚乙烯吡咯烷酮(PVP)为添加剂,调制铸膜液,采用同心圆挤出-涂覆法制备了PAN纤维编织管同质增强型PAN中空纤维膜和异质增强型PVDF中空纤维膜.研究表明,所得PAN纤维编织管增强型中空纤维膜断裂强度最大可超过75 MPa,在伸长率10%范围内,表面分离层与增强体之间界面结合良好;表面分离层具有类似于非对称膜的结构,铸膜液可浸入纤维编织管纤维空隙中,铸膜液浸入部分固化后未影响膜的通透性能;随成膜聚合物浓度增加,膜纯水通量减小,牛血清白蛋白(BSA)截留率增大;随添加剂PVP浓度增加,膜的纯水通量先增大后减小,在8 wt%左右达最大值,BSA截留率随PVP浓度增加而单调增加;同质增强型中空纤维膜界面结合程度优于异质增强型. 相似文献
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耐超高温SiC(A1)纤维先驱体——聚铝碳硅烷纤维的研究 总被引:1,自引:0,他引:1
以聚硅碳硅烷(PSCS)与乙酰丙酮铝(A1(AcAc)3)为原料,在常压高温条件下反应制备出聚铝碳硅烷(PACS),经过熔融纺丝制备了PACS纤维.应用GPC、IR、XPS、^29Si.NMR、^29A1,NMR、TG、SEM、元素分析和增重等一系列分析,分别对PACS纤维的微观组成、结构以及性能进行了分析.研究结果表明,以原料质量配比为6:100(AI(AcAc)3:PSCS)合成的PACS化学式为SiQ2.0H7.5O0.13,Al0.018数均分子量为1700左右,最适宜制备PACS纤维;PACS纤维中主要存在SiC4、SiC3H等结构,同时存在si—O—Al键;在氮气气氛中,PACS纤维的陶瓷产率达到52%左右;预氧化处理,PACS纤维中Si—H键与空气中的氧反应形成Si—O—Si交联结构,较聚碳硅烷(PCS)纤维易于氧化,经过预氧化的PACS纤维陶瓷产率达到80%左右,是制备耐超高温SiC(A1)陶瓷纤维的合适纤维;用预氧化PACS纤维制备的SiC(OAl)纤维和SiC(A1)纤维抗拉强度高,耐高温性能好. 相似文献
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Dietary fiber is a widely recognized nutrient for human health. Previous studies proved that dietary fiber has significant implications for gastrointestinal health by regulating the gut microbiota. Moreover, mechanistic research showed that the physiological functions of different dietary fibers depend to a great extent on their physicochemical characteristics, one of which is solubility. Compared with insoluble dietary fiber, soluble dietary fiber can be easily accessed and metabolized by fiber-degrading microorganisms in the intestine and produce a series of beneficial and functional metabolites. In this review, we outlined the structures, characteristics, and physiological functions of soluble dietary fibers as important nutrients. We particularly focused on the effects of soluble dietary fiber on human health via regulating the gut microbiota and reviewed their effects on dietary and clinical interventions. 相似文献
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Kamila Kapusniak Karolina Lubas Malwina Wojcik Justyna Rosicka-Kaczmarek Volodymyr Pavlyuk Karolina Kluziak Idalina Gonalves Joana Lopes Manuel A. Coimbra Janusz Kapusniak 《Molecules (Basel, Switzerland)》2021,26(18)
Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content. 相似文献
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Ivana Lon
arevi Biljana Pajin Jovana Petrovi Ivana Nikoli Nikola Maravi urica A
kar Drago ubari Danica Zari Borislav Mili
evi 《Molecules (Basel, Switzerland)》2021,26(19)
Resistant starch (RS) is a part of insoluble dietary fiber, and it could be recognized as a functional food ingredient in some types of confectionery products that lack dietary fiber. Unlike dark and milk chocolate, white chocolate does not contain fat-free cocoa solids rich in dietary fiber. In the present study, 5%, 10%, and 15% of white chocolate were substituted with RS in order to improve the nutritional value of enriched white chocolate. The influence of RS on rheological, textural, and thermal properties of the chocolate fat phase was firstly investigated, and then further influence on physical properties, dietary fiber content, and sensory characteristics of enriched white chocolates were investigated. The obtained results showed that enriched chocolates had increased content of total dietary fiber and reduced total fats and protein content in accordance with the added amount of RS. At the same time, RS increased viscosity and reduced the hardness and volume mean diameter in enriched chocolates in accordance with the added amount. RS improved the nutritional composition of white chocolate by increasing the content of dietary fiber. At the same time, RS did not impair the color and sensory characteristics of enriched white chocolates. 相似文献
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Iza F. Prez-Ramírez Ana M. Sotelo-Gonzlez Gerardo Lpez-Echevarría Miguel A. Martínez-Maldonado 《Molecules (Basel, Switzerland)》2023,28(1)
There is an increasing interest in the development of meat processed products enriched with antioxidant dietary fiber to augment the consumption of these health beneficial compounds. This study aimed to evaluate the nutritional, nutraceutical, and antioxidant potential, as well as the physicochemical properties of minced tilapia fillets (meat) gels with added amaranth seed or sprout flours (0%, 2%, 4%, 8%, and 10% w/w). Dietary fiber content was significantly increased with the addition of amaranth seed (1.25–1.75-fold) and sprout flours (1.99–3.21-fold). Tilapia gels with added 10% amaranth seed flour showed a high content of extractable dihydroxybenzoic acid and cinnamic acid, whereas the addition of 10% amaranth sprout flour provided a high and wide variety of bioactive compounds, mainly amaranthine and bound ferulic acid. The addition of amaranth seed and sprout flours increased hardness (1.01–1.73-fold) without affecting springiness, decreased luminosity (1.05–1.15-fold), and increased redness and yellowness. Therefore, amaranth seed and sprout flours could be used as functional ingredients for the development of fish products rich in bioactive compounds. 相似文献
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为了解重庆市某高校学生膳食铬的摄入水平,随机选取调查对象120人,双份饭法采样食物,用火焰原子吸收分光光度法测定了膳食中铬的含量。结果表明,大学生膳食铬的平均摄入量男生为4.68 mg/d,女生为3.80 mg/d,分别是适宜摄入量(adequate Intake,AI)的23.4倍和19倍,也显著超过了铬的每日允许摄入量(acceptable daily Intake,ADI)1.0 mg/d。可见高校学生膳食铬摄入水平超过了推荐膳食摄入量和安全限量,但其对健康的影响有待进一步明确。 相似文献
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Laura Maletti Veronica DEusanio Caterina Durante Andrea Marchetti Lorenzo Tassi 《Molecules (Basel, Switzerland)》2022,27(24)
In this study, the trend of VOCs of dietary fiber samples, coming from three different watermelon cultivars Citrullus lanatus L. (variety Gavina®®, Crimson Sweet, and Asahi Miyako) was investigated. This foodstuff, obtained as a by-product of residual agri-food production, has gained increasing attention because of its many bioactive components and high dietary fiber content. The result is a fibrous material for specific applications in food manufacturing, such as corrector for some functional and technological properties. In this study, a method based on headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS) was used to characterize the aromatic profiles of the dried raw materials. Therefore, the VOCs of the samples of the three cultivars were investigated. Experimental results have shown that watermelon fibers generate VOCs, which can be grouped into six common classes of analytes. The different distributions of the identified compounds made it possible to effectively differentiate the three cultivars studied based on their peculiar aroma profiles. In particular, Gavina®® fiber is distinguished by the high content of terpenes, Asahi Miyako by the presence of aldehydes generated as fatty acid metabolites, and Crimson Sweet by the higher content of acetyl esters. 相似文献