广西巴马长寿人群饮食中7种膳食纤维成分及抗氧化活性分析

目的探索广西巴马长寿人群饮食中代表性膳食纤维的作用。方法选取广西巴马长寿人群膳食中7种代表性果蔬为原料,采用水提醇沉工艺对其进行膳食纤维的提取,获得其中的水溶性膳食纤维(soluble dietary fiber, SDF)和水不溶性膳食纤维(insoluble dietary fiber, IDF)并对其组成成分、吸附能力、抗氧化效果等方面进行比较。结果 7种SDF含量、多糖含量、果胶含量、半纤维素含量最高分别是脐橙、南瓜苗、红薯叶、脐橙,分别为67.28%、63.52%、70.46 mg/g、94.23 mg/g; 7种IDF纯度、半纤维素含量、纤维素含量、木质素含量最高的分别是茶树菇、香蕉、茶树菇、空心菜,分别为70.39%、158.86mg/g、51.34mg/g、572.96mg/g。7种SDF和7种IDF中持水力、膨胀力、持油力最大的分别是茶树菇SDF、脐橙SDF、香蕉SDF,依次为14.23 g/g、9.29 mL/g、5.18 g/g;清除DPPH能力最强的是南瓜苗SDF,清除率为73.34%; NO_2~-、胆固醇吸附能力最强的分别是脐橙SDF、茶树菇SDF,依次为17.23、15.99μmol/mg。结论广西巴马长寿人群膳食中7种SDF及7种IDF的灰分及蛋白等杂质含量较低,具有清除胆固醇、NO_2~-、DPPH的作用。     

黑麦麸膳食纤维的结构和功能特性研究

以黑麦麸为原材料,采用酶法制备膳食纤维并分别测定2种膳食纤维的结构、单糖和酚类物质组成及功能特性。结果表明:可溶性膳食纤维(SDF)的表面疏松松散,主要由阿拉伯糖(68%)、半乳糖(13.1%)和木糖(12.2%)组成;不溶性膳食纤维(IDF)表面多孔不规则,主要由木糖(54%)和阿拉伯糖(38.3%)组成。两种膳食纤维均具有糖类红外特征吸收峰,IDF结晶度高于SDF,结构更加规则,SDF表现出更好的吸水力(2.19 g/g)、吸附胆固醇的能力(2.09 mg/g,pH=7)和吸附亚硝酸根的能力(327 μg/g,pH=2)。采用高效液相色谱分析SDF和IDF的酚类物质组成,IDF中的酚类物质组成及含量均显著高于SDF(P<0.05),二者的酚类化合物主要是结合型阿魏酸。     

豆渣膳食纤维对酥性饼干特性的影响

将豆渣中酶法提取的可溶性膳食纤维(豆渣SDF)、不溶性膳食纤维(豆渣IDF)以及商业菊粉,分别添加到酥性饼干中,研究其对饼干的物理化学特性和感官品质的影响。结果表明:添加豆渣IDF的饼干持水性和硬度较高,添加豆渣SDF和菊粉的饼干松密度值和过氧化值较低,且两者的松密度值没有较大差异,而添加豆渣IDF的饼干与之相反,添加4%豆渣SDF的饼干感官评定结果最优,且总膳食纤维、水分和脂肪含量较空白高,而蛋白质和灰分含量没有明显变化。     

不同种类燕麦和苦荞中的膳食纤维测定

采用酶- 重量法分析不同产地的15 种燕麦和苦荞中总膳食纤维(TDF)、可溶性膳食纤维 (SDF)及不溶性膳食纤维(IDF)的含量。对于燕麦,TDF 含量平均为12%,其中黑龙江的米燕麦、山西的73014-336、河北的小莜麦样品含量较多,而青海的玉麦-2、宁夏的固原燕麦和云南的德钦燕麦含量较低;黑龙江的米燕麦的SDF 含量明显高于其他燕麦;河北的小莜麦和山西的73014-336 中IDF 含量较高;国外的Bup-1809 燕麦的TDF、SDF、IDF含量都低于平均值。对于苦荞,TDF 含量平均为7%,四川的额洛木尔惹苦荞的含量最高,为9.64%;贵州的90-3 苦荞的SDF 含量最高,为3.45%;四川的额洛木尔惹苦荞和山西的蔓荞子苦荞中的IDF 含量较高。酶- 重量法测定植物中膳食纤维其重现性较好,不同产地、不同种类燕麦和苦荞中膳食纤维含量与组成差异较大。     

微波辅助法和酶法制备苹果渣膳食纤维特性研究

以苹果渣为原料,分别采用微波辅助法和酶解法制备水溶性膳食纤维(SDF)和不溶性膳食纤维(IDF),对4种膳食纤维超微结构进行了比较,并研究了其持水力、溶胀性、油脂吸附力和胆酸钠吸附性,以期为制备高活性苹果渣膳食纤维提供依据。结果表明:微波辅助法和酶法制备的苹果渣SDF结构松散,呈现絮状和颗粒状,IDF呈片状;SDF具有良好的持水力和溶胀性,与IDF存在显著性差异,微波法和酶法SDF的持水力分别达752.3%和793.2%,溶胀性分别为11.1 m L/g和13.05 m L/g;SDF油脂吸附能力高于IDF,对饱和油脂吸附效果更加明显;苹果渣IDF对胆酸钠吸附能力强于SDF,以微波辅助法提取的IDF对胆酸钠的吸附能力最好,为93.33 mg/g。     

动态高压微射流对刺梨果渣膳食纤维及其抑制淀粉消化和葡萄糖扩散的影响

本实验以刺梨果渣为原料,采用酶法制备可溶性膳食纤维（soluble dietary fiber,SDF）、不可溶性膳食纤维（insoluble dietary fiber,IDF）和全膳食纤维（total dietary fiber,TDF）,并采用动态高压微射流（dynamic high pressure microfluidization,DHPM）对刺梨果渣SDF进行改性处理,初步探索了刺梨果渣膳食纤维及DHPM处理SDF（DHPM-SDF）的理化特性及其对淀粉酶活力和葡萄糖扩散的影响。结果表明,IDF和SDF都能通过吸附葡萄糖、抑制葡萄糖扩散以及改变胰淀粉酶二级结构来减缓葡萄糖的流动进程和淀粉消化速率,其中,IDF对葡萄糖的吸附能力和抑制葡萄糖扩散能力分别是SDF的1.28 倍和1.99 倍,而SDF的胰淀粉酶活力抑制率是IDF的1.73 倍,并且,SDF对胰淀粉酶活力的抑制作用主要通过改变胰淀粉酶的α-螺旋和无规卷曲结构。TDF表现出与IDF相似的葡萄糖吸附能力和抑制淀粉酶活力的能力。与SDF相比,DHPM-SDF平均粒径增加了2.08 倍,使得其葡萄糖吸附能力和抑制葡萄糖扩散能力分别提高了28.13%和62.09%,并且DHPM-SDF能显著减少胰淀粉酶的α-螺旋和无规卷曲结构相对含量（P＜0.05）,其对淀粉酶活力的抑制能力是SDF的1.44 倍。因此,刺梨果渣膳食纤维,尤其是SDF可作为降血糖产品开发的潜在优良资源,并且DHPM是提高刺梨果渣可溶性膳食纤维降血糖活性的有效改性处理手段。     

脱脂对不同生长期苜蓿膳食纤维含量及其提取得率的影响

目的:研究脱脂对苜蓿膳食纤维含量、构成及其提取得率的影响,为该方法在苜蓿膳食纤维提取中的合理应用提供科学依据。方法:以初花期和结荚期苜蓿草粉为原料,研究脱脂前后苜蓿草粉中膳食纤维含量、构成及其提取得率的变化规律。结果:苜蓿膳食纤维以水不溶性膳食纤维(IDF)为主,开花后苜蓿IDF含量占膳食纤维总量(TDF)的90%以上;脱脂后的初花期和结荚期苜蓿草粉中,IDF含量分别达72.88%、73.62%,比脱脂前分别提高61.38%、38.12%;IDF在TDF中的比例分别由90.09%、92.82%提高至95.19%、95.71%,IDF提取得率分别达61.52%、72.11%,比脱脂前分别提高69.94%、48.62%;脱脂过程中水溶性膳食纤维(SDF)流失严重、含量降低,SDF提取得率下降92.68%和92.29%。结论:脱脂方法适用于结荚期苜蓿IDF提取原料的前处理,但不适于苜蓿SDF的提取。     

苦荞中可溶性及不可溶性膳食纤维调控糖尿病小鼠糖脂代谢的功效

本研究采用苦荞麸皮粉中提取的膳食纤维对高脂/链脲佐菌素诱导的糖尿病小鼠进行干预,比较苦荞麸皮粉中的可溶性膳食纤维（soluble dietary fiber,SDF）和不可溶性膳食纤维（insoluble dietary fiber,IDF）的含量及作用差异,解析苦荞中SDF及IDF对调控糖尿病小鼠血糖及血脂代谢作用的贡献。结果：苦荞麸皮中IDF的质量分数（（19.52±0.21）%）约为SDF（（4.02±0.19）%）的5 倍;相同干预剂量下SDF比IDF能更有效地发挥降血糖作用,但当IDF干预剂量达到SDF的5 倍时,IDF降低血清中的总胆固醇和低密度脂蛋白胆固醇水平的效果更显著（P＜0.05）,并且能够和SDF一样有效促进胰岛素分泌并改善糖耐量、降低肝脏中总胆固醇水平、促进短链脂肪酸的产生。结论：苦荞SDF和IDF均具有改善糖耐量、降低血清及肝脏中脂肪积累的功效,且都与盲肠中短链脂肪酸含量的增加密切相关;研究揭示了苦荞SDF及IDF在量效关系上的差异,为充分理解谷物中不同膳食纤维的糖脂调控功效提供了科学证据。     

甘薯膳食纤维构成及对乙醇发酵的影响

对14个甘薯品种(系)的膳食纤维构成成分进行了测定,分析了不同品种甘薯膳食纤维含量和组成差异及其对乙醇发酵的影响。结果表明:甘薯总膳食纤维(TDF)、不溶性膳食纤维(IDF)、可溶性膳食纤维(SDF)含量平均值分别为16.05、11.89、4.16 g/100 g干物质,变异系数分别为15.08%、13.79%、23.31%;甘薯果胶、半纤维素、纤维素和木质素含量平均值分别为33.35、37.46、21.10、2.13 g/100 g DF,变异系数分别为7.44%、16.68%、21.52%、16.89%,不同品种甘薯膳食纤维含量和组成差异显著。相关性分析表明,甘薯膳食纤维含量、各组成成分之间均显著正相关;发酵黏度与SDF、SDF/IDF、果胶显著正相关,而乙醇产量、发酵效率与膳食纤维相关性均不显著,因此甘薯果胶等SDF是影响乙醇发酵特性的重要因素。提高甘薯TDF和SDF含量可以作为高膳食纤维专用品种的选育方向。     

椪柑皮渣膳食纤维碱法提取工艺优化及其主要功能特性研究

以提取黄酮后的椪柑皮残渣为原料，采用单因素试验探究了可溶性膳食纤维(Soluble dietary fibre, SDF)、不溶性膳食纤维(Insoluble dietary fibre, IDF)和总膳食纤维(Total dietary fibre,TDF)的碱法提取工艺，以及正交试验优化TDF的碱法提取工艺，并分析其成分组成、微观结构和主要功能性质。结果表明：最佳提取工艺条件为pH10.0、提取温度65℃、料液比1:20 g/mL、提取时间70 min，该条件下SDF、IDF和TDF的提取率分别为15.49%、60.35%和75.84%；膳食纤维(Dietary fiber,DF)是椪柑皮渣的主要组成成分，含量达82.10%，具有典型纤维网状结构；其持水力、持油力和膨胀力比椪柑皮渣显著增加。该研究显示碱法提取工艺提取椪柑皮渣SDF、IDF和TDF，具有良好的功能特性，为椪柑皮功能成分的分步提取与开发利用提供技术基础。     

Effect of modified dietary fiber extracted from wholegrain wheat on the physicochemical and cake properties

Dietary fiber (DF) extracted from whole wheat was chemically modified by cross-linking (CL), carboxymethylation (CM), and hydroxypropylation (HP) and their physicochemical properties and baking performance were evaluated. CM contributed to the increase in soluble DF (SDF) contents and water solubility. While CL and HP contributed to the decrease in water solubility as insoluble DF (IDF) contents increased. In comparison to the chemically modified DF, CLDF deteriorated textural and physical properties of cakes. On the other hand, the cakes with CMDF and HPDF had improved cake qualities such as appearance, higher volume and lower hardness compared to cake with native DF. Consequently, this study suggested that the chemical modifications of wheat DF can effectively regulate the IDF/SDF ratio and total dietary fiber (TDF) contents, resulting in the change of physicochemical properties of them. When applied to cake, modified wheat DF diversified the physicochemical properties and quality by a functional group.     

Fibre concentrate from mango fruit: Characterization, associated antioxidant capacity and application as a bakery product ingredient

Mango is a still underutilized fruit from tropical regions. The aim of this work was to characterize a mango dietary fibre concentrate (MDF) with antioxidant capacity, using the unripe fruit. MDF was obtained and its chemical composition, soluble (SDF) and insoluble dietary fibre (IDF), extractable polyphenols, water- and oil-holding capacities and anti-radical efficiency, were evaluated. MDF showed low lipid and high starch contents and balanced SDF/IDF levels, which is important for the functionality of fibre in the human diet. MDF exhibited adequate water-holding capacity, similar to other fruit fibres, but had a low oil-holding capacity. Bakery products prepared with MDF conserved the balance of SDF and IDF and most of its anti-radical efficiency. In vitro starch digestibility tests of MDF bakery products indicated a low predicted glycemic index. MDF might be an alternative for development of products with balanced DF components and low glycemic response, aimed to people with special carbohydrate/energy requirements.     

Effect of different chemical modification on the physicochemical properties of fiber-enriched polysaccharides isolated from wholegrain rice and buckwheat

Dietary fiber (DF) isolated from wholegrain flours (brown rice and buckwheat) were chemically modified by cross-linking (CL), carboxymethylation (CM) and hydroxypropylation (HP). The modified DF was evaluated for its physicochemical characteristics based on compositions, hydration properties and interactions of wheat starch/DF system. The changes in total dietary fiber (TDF) content of were found to be chemical modification-dependent. CM contributed to the increase in soluble dietary fiber (SDF) contents and water solubility. On the contrary, CL and HP significantly increased the insoluble dietary fiber (IDF) contents, resulted in reduced water solubility. Hydration properties of both native and modified buckwheat DF were higher than all rice DF counterparts. In the interaction with wheat starch, starch hydrolysis was low in samples with high TDF contents (CL≈HP>CM≈ native). It was concluded that characteristics of modified cereal DF depended on the presence of functional groups rather than sources of wholegrain.     

柠檬皮渣膳食纤维制备工艺研究

以柠檬皮渣为原料,分别采用水和95%的乙醇为溶剂在不同温度下制备柠檬膳食纤维,并测定其膳食纤维组成和理化特性。结果表明：柠檬膳食纤维制备的工艺条件采用水在室温下处理1min,并进行冷冻干燥,可以得到总黄酮含量、VC含量和持油力较好的产品;柠檬膳食纤维制备的工艺条件采用乙醇在60℃处理90min,并进行冷冻干燥,可以得到SDF/IDF（可溶性膳食纤维/不溶性膳食纤维）比值合理、持水力、粘度、白度都较好的产品。     

Sources of error in dietary fibre analysis

The following error sources in the present dietary fibre (DF) analytical methods were investigated: (1) the omission of the protease treatment of samples may modify the results by increasing the Klason lignin fraction and altering the content and/or distribution of polysaccharides; (2) some soluble dietary fibre (SDF) constituents can be retained in the insoluble dietary fibre (IDF) matrix affecting the insoluble and soluble fraction distribution; (3) protein, ash and blank corrections in gravimetric analysis involve a lack of precision, over- or undervaluing the actual DF contents; (4) the Klason lignin fractions obtained by acid hydrolysis of DF residues are made up of different components and artifacts besides lignin.

These studies included both new observations and additional quantitative evidence on error sources previously mentioned in the literature. In some cases the published methods were modified to emphasize the methodological errors.     

气相色谱法分析北方水果中膳食纤维的单糖组成

采用糖腈乙酰化衍生GC法分析中国北方地区7种水果(苹果、梨、桃、杏、山楂、草莓和桑椹)膳食纤维(DF)的含量和单糖组成,结果表明这些水果中总膳食纤维(TDF)含量在0.26%(杏)～1.17%(桃)之间,其中水溶性膳食纤维(SDF)占TDF的比例在38.5%(杏)～86.3%(桃)之间。半乳糖醛酸是SDF的主要成分,占33.1%(桑椹)～91.1%(山楂)之间。不溶性膳食纤维中除含有较高比例的半乳糖醛酸(4.5%～46.5%)外,阿拉伯糖(9.4%～37.7%)、半乳糖(8.3%～24.2%)、木糖(8.7%～20.3%)和岩藻糖(8.0%～23.7%)也有相当含量,葡萄糖的比例在0.7%(桃)～15.6%(山楂)之间,甘露糖和鼠李糖的比例在6%以下。不同水果之间DF的单糖组成差异明显。     

Non‐digestible carbohydrates in Brazilian soybean seeds [Glycine max (L.) Merril]

Non‐digestible carbohydrate fraction (NDCF) consists of a range of bioactive compounds that escape digestion in the small intestine. NDCF is mainly composed of dietary fibre (DF) and non‐digestible oligosaccharides (NDO). The objective of this work was to analyse directly and compare the NDCF in two Brazilian cultivars of soybean seed with commercial flour. Brazil is the second major soybean producer in the world. The seed cultivars showed on average a NDCF value of 32.80 g per 100 g dry weight (dw). Regarding DF, insoluble DF (IDF) was the main fraction amounting on average to 98%. Uronic acids were significantly higher than neutral sugar (NS) in IDF and soluble DF (SDF) fractions. There was a considerable amount of Klason lignin – on average 84.14% of DF. Regarding NS profile, mannose was the most important sugar in SDF, whereas galactose and arabinose were predominant in IDF. Stachyose was the main oligosaccharide in NDO. DF and NDO were in the same proportion (94.2:5.8) in tested cultivars. No differences in swelling, water retention, or oil retention capacities between seed cultivars were detected. This study on non‐digestible carbohydrate components in soybean seed gives a different approach to the current nutritional knowledge on protein and oil constituents.     

琯溪蜜柚柚皮膳食纤维提取及其理化特性

以福建省平和县琯溪蜜柚为材料,以NaOH溶液浓度、提取温度和加热时间设计三因素三水平正交实验,以总膳食纤维(TDF)提取率、不溶性膳食纤维(IDF)与水溶性膳食纤维(SDF)的比值接近3∶1为目标,优化柚皮膳食纤维提取工艺。结果表明:柚皮膳食纤维(DF)最佳提取工艺为碱液浓度8%,提取温度75℃,加热时间90 min,其提取率为75.12%,IDF/SDF比值为2.12。柚皮TDF粒径主要分布在<120目的范围,占总比重的30.13%,其次是位于120～140目的DF膳食纤维,占总比重的21.84%;SDF具有良好的膨胀力,达到17.642 0 g/g,IDF持水力较好,为5.711 5 g/g;柚皮DF对亚硝酸盐(NO2-)吸附能力强,且DF对NO2-的吸附量随着时间的延长而增加,至240 min时吸附量最高,达到18.01 g/g(pH 2)和15.92 g/g(pH 7),相同时间内,在pH 2的模拟环境下,DF对NO2-吸附能力优于pH 7的;柚皮DF对脂肪酸的吸附效果良好,且相同时间内DF对不饱和脂肪酸的吸附量(1.026 0 g/g)高于对饱和脂肪酸的(1.124 0 g/g),说明DF吸附动物性油脂效果更好。     

发酵技术在膳食纤维改性中的应用

膳食纤维(Dietary fiber,DF)被称作"第七营养素",拥有良好的生理功能及活性,其中,可溶性膳食纤维(Soluble dietary fiber,SDF)生理和生物活性优于不可溶性膳食纤维(Insoluble dietary fiber,IDF).然而,植物DF中SDF的含量较低,限制了DF功能性产品的开发...