Modifi cation of wheat bran insoluble and soluble dietary fibers with snail enzyme

Insoluble dietary fiber(IDF)and soluble dietary fiber(SDF)extracted from wheat bran were modifi ed by snail enzyme and their physicochemical properties(water retention capacity and oil retention capacity),functional properties(cholesterol adsorption capacity,glucose adsorption capacity and antioxidant activity)and structural characterizations were evaluated.The results showed that snail enzyme modification led to the significant increase in oil retention capacity of IDF,glucose adsorption capacity and cholesterol adsorption capacity of IDF and SDF.Enzymatic modification also markedly improved the DPPH radical scavenging capacity and reducing power of IDF and SDF.Meanwhile,scanning electron microscopy(SEM)analysis indicated the microstructures of IDF and SDF powders were signifi cantly changed.Fourier transfer-infrared spectrometry(FT-IR)showed that snail enzyme modifi cation could degrade the part of cellulose and hemicellulose of IDF and SDF.All these improved physicochemical and functional properties of IDF and SDF might depend on their structural changes.It suggested that snail enzyme modifi cation could effectively improve physicochemical and functional properties of IDF and SDF from wheat bran.

Study on Functional and Structure Properties of Soluble Dietary Fiber Modified by Extrusion-expansion Technology from Peanut Shells

[Objectives] This study was conducted to investigate the feasibility of using modified peanut dietary fiber as a functional food ingredient. [Methods]Using peanut shells as a test material,the process parameters of soluble dietary fiber( SDF) modified by extrusion and expansion were studied,and the functional and structural characteristics of SDF before and after modification were discussed. [Results] The optimum conditions were as follows: screw speed 200 rpm,temperature 130 ℃ and moisture content 20 %,and the SDF extraction yield was 22. 3%. The modified SDF showed BCmax values of( 378. 5 ± 5. 3),( 278. 3 ± 3. 2)and( 167. 2 ± 2. 5) μmol/g and BCmin of( 30. 4 ± 1. 3),( 63. 4 ± 3. 7) and( 71. 3 ± 4. 2) μmol/L,for Pb,As and Cu,respectively,indicating that the adsorption to the three heavy metals was enhanced. The modified SDF had a porous network like honeycomb and swelled structure. [Conclusions]Therefore,it is feasible to modify SDF by extrusion and expansion.

Soluble Fiber Improves Management of Diarrhea in Elderly Patients Receiving Enteral Nutrition

Dietary fiber is a non-digestible carbohydrate providing beneficial effects for bowel health. The aim of this study was to evaluate the clinical effects of fiber supplementation in enteral feeding on elderly patients suffering from diarrhea. This study was conducted in 15 patients (7 men and 8 women, 79.0 ± 7.5 years) who had loose stools or diarrhea during enteral nutrition. The enteral formula was supplemented with soluble dietary fiber (5.2 g/day) for 3 weeks, which was then discontinued for 1 week to confirm its effects. The effects of soluble dietary fiber on stool frequency, the Bristol Stool Form Scale (which is designed to measure stool consistency), plasma diamine oxidase (DAO) activity, and concentrations of plasma short-chain fatty acids (SCFA) were evaluated. After supplementation with soluble dietary fiber, there were no significant differences in stool frequency but there was a significant improvement in stool consistency (P < 0.05). Furthermore, ingestion of soluble dietary fiber resulted in increased plasma DAO activity and significantly increased levels of plasma SCFA (P < 0.05). Supplementation with soluble dietary fiber may be beneficial for improving stool consistency in patients suffering from diarrhea during enteral nutrition. A further controlled trial is warranted to examine the preventive effects of soluble dietary fiber in patients suffering from diarrhea.

SDF+合生元对老年重症AECOPD肠内营养患者营养和耐受性及肠屏障功能影响

背景老年重症慢性阻塞性肺部疾病急性加重期(acute exacerbation of severe chronic obstructive pulmonary disease,AECOPD)患者,由于年龄和身体的原因,时常发生营养不良,影响病情的转归,需要给予较高质量的肠内营养支持,但是极易发生腹泻、腹胀等不良反应,提高患者肠内营养耐受性成为解决问题的必要途径.目的探讨可溶性膳食纤维(soluble dietary fiber,SDF)+合生元对老年重症AECOPD肠内营养患者营养和耐受性及肠屏障功能影响.方法随机数字表法将2020-01/2022-10我院收治的208例老年重症AECOPD患者分为4组,各52例.常规组给予常规肠内营养,在此基础上,SDF组添加SDF,合生元组添加合生元,联合组添加SDF+合生元.比较各组营养支持前、第8 d、第15 d营养状态[血清总蛋白(total protein,TP)、血红蛋白(hemoglobin,HGB)、前白蛋白(prealbumin,PA)、白蛋白(albumin,ALB)]、目标能量达标时间、机械通气时间、ICU住院时间、总住院时间、血糖水平、胰岛素用量、肠屏障功能[二胺氧化酶(diamine oxidase,DAO)、内毒素、D-乳酸]、免疫功能[CD4+/CD8+、免疫球蛋白A(immunoglobulin A,IgA)、免疫球蛋白M(immunoglobulin M,IgM)、免疫球蛋白G(immunoglobulin G,IgG)]、不良反应、耐受性、感染及生存率.结果SDF组、合生元组、联合组第8 d、第15 d的TP、HGB、PA、ALB均高于常规组,且联合组高于SDF组、合生元组(P<0.05);SDF组、合生元组、联合组目标能量达标时间、机械通气时间、ICU住院时间、总住院时间短于常规组,且联合组短于SDF组、合生元组(P<0.05);SDF组、合生元组、联合组第8 d、第15 d的血糖水平、胰岛素用量均低于常规组,且联合组低于SDF组、合生元组(P<0.05);SDF组、合生元组、联合组第8 d、第15 d的DAO、内毒素、D-乳酸均低于常规组,且联合组低于SDF组、合生元组(P<0.05);合生元组、联合组第8 d、第15 d的CD4+/CD8+、IgA、IgM、IgG均高于常规组、SDF组,且联合组高于合生元组(P<0.05);联合组、SDF组、合生元组耐受性相关的不良反应总发生率低于常规组(P<0.05);联合组感染率低于常规组、SDF组、合生元组(P<0.05).结论SDF+合生元可提高老年重症AECOPD患者对肠内营养耐受性,改善患者营养状态和血糖水平,减少胰岛素应用,增强肠屏障和免疫功能,降低感染率,加快患者康复进程.

The effects of dietary fiber level on nutrient digestibility in growing pigs

The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.

A Review of the Associations between Dietary Fiber Intake and Cancer Prevention or Prognosis

The increase in tumor incidence is closely related to dietary factors.In recent years,many researchers have carried out in-depth research to investigate whether increasing the intake of dietary fiber can prevent tumors and improve the prognosis,but the results have been unclear.We herein searched the literature in common academic databases and incorporated and summarized the relevant articles.The literature clearly indicates that dietary fiber can protect against the following cancers:colorectal cancer,breast cancer,pancreatic cancer,ovarian cancer,and head and neck cancer.There is also evidence that dietary fiber intake can exert protective effects against cancers of the liver,lung,stomach,small bowel,kidney,and esophagus,as well as lymphoma,but the data have so far been relatively limited.The effects on endometrial cancer and prostate cancer still remain uncertain.In terms of the effects on the cancer prognosis,dietary fiber does not appear to have an impact on colorectal cancer or breast cancer.Although more research is needed for some kinds of cancer,it is clear that increasing the intake of dietary fiber is beneficial for preventing the occurrence and development of several major types of cancer,with no major adverse effects.We therefore recommend that most of individuals increase their intake of dietary fiber.

蒸制对甘薯可溶性膳食纤维提取、理化性质及消化特性的影响

目的:考察蒸制前、后甘薯中可溶性膳食纤维(SDF)提取、组成及性质的差异。方法:为获得高品质甘薯SDF,以提高提取得率和SDF总多糖含量为目标,采用响应面分析和满意度函数方法优化料液比、提取温度、提取时间3个参数,建立甘薯SDF提取工艺。从蒸制前、后的甘薯中提取得到生鲜甘薯膳食纤维(SDF-F)和蒸制甘薯膳食纤维(SDF-S),对比两者提取得率、多糖组成、膳食纤维含量以及持水力和持油力等理化性质差异,并做体外模拟消化试验。结果:优化的提取工艺参数为:料液比1∶16、提取温度40℃、提取时间40 min。在此工艺条件下,SDF-S的提取得率【(6.13±0.25)%vs(2.89±0.18)%】、中性多糖含量【(59.31±0.73)%vs(46.83±0.63)%】、酸性多糖含量【(25.36±0.48)%vs(9.60±0.14)%】、膳食纤维含量【(54.71±6.70)%vs(35.69±3.25)%】、持水力【(4.60±0.31)g/g vs(3.27±0.21)g/g)】和持油力【(3.30±0.40)g/g vs(1.82±0.28)g/g)】显著高于SDF-F(P<0.05),而SDF-F的抗消化性优于SDF-S。结论:蒸制处理虽提高了甘薯SDF的可及性,但导致SDF的抗消化性减弱。

麦麸可溶性和不溶性膳食纤维对小麦淀粉性质的影响

为了提高膳食纤维摄入量、促进麦麸在面制品中的应用,按照麦麸中可溶性和不溶性膳食纤维的比例分别构建膳食纤维-淀粉混合体系,探讨麦麸可溶性和不溶性膳食纤维对小麦淀粉糊化、热学、流变和消化性质的影响。结果表明:麦麸中可溶性膳食纤维和不溶性膳食纤维对小麦淀粉性质的影响有所差异,麦麸可溶性膳食纤维对小麦淀粉性质影响效果更明显。

超声辅助低共熔溶剂制备咖啡果皮可溶性膳食纤维

为进一步探索制备咖啡果皮中可溶性膳食纤维的绿色新方法。本研究建立了一种省时、高效、环保的超声辅助低共熔溶剂(UAE-DESs)制备咖啡果皮可溶性膳食纤维(SDF)的方法,并通过单因素试验和响应面试验优化了其工艺参数。采用加热法制备了8种氯化胆碱基的DESs作为提取溶剂,并与传统水提法作对比。结果表明:氯化胆碱与尿素摩尔比为1∶2的DES体系制备的咖啡果皮SDF得率最高,为10.10%±0.11%,显著高于传统水提法(6.50%±0.22%)。通过单因素实验,探讨了DES组成(摩尔比、含水量、液固比)和超声波处理(超声功率、超声时间)对咖啡果皮SDF得率的影响。在此基础上,采用响应面法(RSM)结合Box-Behnken设计(BBD)对SDF得率进行优化,考察DES含水量、液固比、超声功率和超声时间对SDF得率的影响。根据RSM的优化结果,确定最佳制备条件为:DES含水量为39.91%,液固比为32.37 mL/g,超声功率为305.20 W,超声时间为33.80 min,在此条件下,咖啡果皮SDF得率最大,为10.74%±0.14%,与其预测值10.80%接近。因此,DES作为一种高效、无污染的绿色溶剂,可用于咖啡果皮SDF的制备。本研究结果将为咖啡果皮可溶性膳食纤维的制备提供新思路和理论参考,并在咖啡副产物的增值利用、生产新型高附加值产品以及开发天然功能性食品等方面具有潜在的应用前景。

沅江芦笋可溶性膳食纤维提取工艺的优化

以沅江芦笋为原料,通过超声辅助酶法提取可溶性膳食纤维,探讨α-淀粉酶与糖化酶质量比、浸提时间、超声功率、超声温度以及料液比对可溶性膳食纤维提取得率的影响,并采用正交试验优化可溶性膳食纤维最佳提取工艺。结果表明,最佳提取工艺条件为料液比1∶200(g/mL),α-淀粉酶与糖化酶质量比5∶5,浸提时间4 h。在该工艺条件下沅江芦笋可溶性膳食纤维提取得率为16.77%。

双螺杆挤出工艺对人参渣中SDF含量的影响

以人参加工厂废弃的人参渣为原料,采用双螺杆挤出技术对其进行低聚化处理,提高人参渣中可溶性成分的含量。采用单因素实验考察了水分添加量、挤出温度和物料粒度对可溶性膳食纤维(Soluble Dietary Fiber,SDF)含量的影响,并在单因素实验的基础上,通过响应面实验对工艺进行优化。采用凝胶色谱法测定挤出前后人参渣中SDF组分的分子量分布。结果表明,双螺杆挤出的最佳工艺参数为:水分添加量142%,挤出温度162℃,物料粒度目数80目,在最佳条件下SDF得率为24.94%。挤出后人参渣中SDF多糖的分子量分布在12915和5201,均达到了高品质膳食纤维的功能活性要求。

梨渣可溶性膳食纤维提取工艺优化及功能特性分析

采用纤维素酶酶解制备梨渣可溶性膳食纤维(SDF),以梨渣SDF得率为评价指标,通过单因素和响应面优化酶解制备SDF的最佳工艺条件,并分析可溶性膳食纤维的理化性质和功能特性。结果表明,SDF最佳提取工艺为酶底质量比1.1%、时间5.2 h、料液比1:21、温度37℃、pH值4.5,在此条件下进行的验证试验SDF得率为6.29%,与理论值6.23%较相符。与原梨渣相比,SDF的持水性和膨胀性均得到提高,且SDF对DPPH(IC_(50)=0.494 mg/mL)和ABTS+(IC_(50)=0.429 mg/mL)自由基具有一定的清除能力,表现出较好的抗氧化活性。SDF在肠道中表现出更好的胆固醇吸附能力(4.81 mg/g),但在胃环境(84.68%)中对NO2-的吸附能力显著高于肠道环境(16.21%)。梨渣可溶性膳食纤维具有较好的理化功能特性,该研究为梨渣的高值化利用提供了理论依据。

乳酸菌固态发酵过程中麦麸组分的动态变化

麦麸是小麦加工的主要副产物,营养丰富且产量大,采用乳酸菌处理麦麸可提高其附加值。为明确乳酸菌发酵对麦麸各组分的影响,作者采用植物乳杆菌、鼠李糖乳杆菌、戊糖片球菌和布氏乳杆菌分别对麦麸进行固态发酵,在48 h内每隔8 h取样,分析可溶性膳食纤维、粗蛋白质、淀粉、总酚、植酸等成分的质量分数及DPPH自由基清除能力的动态变化。结果表明,在麦麸基质中,4株乳酸菌在24 h内生长较为迅速;麦麸经乳酸菌发酵后可溶性膳食纤维质量分数显著提高,其中布氏乳杆菌发酵48 h后可溶性膳食纤维质量分数由4.72%增加至6.58%;随着发酵时间的增加,麦麸中淀粉质量分数逐渐降低,粗蛋白质量分数先增加后降低最后趋于稳定;植物乳杆菌在提高麦麸多酚质量分数方面有更好的效果,多酚质量分数由1.34 mg/g增加至3.86 mg/g,麦麸抗氧化活性显著增加;此外,乳酸菌发酵麦麸可显著降低其植酸质量分数。综合而言,植物乳杆菌和布氏乳杆菌在提高麦麸的营养特性方面具有较好的效果,可有效改善麦麸的综合利用价值。

酶解-重力法测定膳食纤维中SDF与IDF的研究

介绍了一种测定 SDF和 IDF的快速酶解 -重力分析法。这种方法的要点依次是 :样品先与 Termamyl一起煮沸 15 min,然后用胃蛋白酶在 p H1.5、40℃水解 1h,再加入胰蛋白酶在 p H6.8、40℃水解 1h,IDF被硅藻土 -5 45过滤分离出来 ,SDF则用其 4倍体积 95 %的乙醇沉淀并过滤分离。此法酶解时间仅需 2～ 3 h,1d即可测试 10～

豆渣可溶性膳食纤维的提取及其制备可食用膜的研究

豆渣是大豆加工的大宗副产物,富含膳食纤维。采用微波辅助酶解水提法提取豆渣可溶性膳食纤维(SDF),然后将其制成可食用膜。通过单因素试验和正交试验优化后的提取工艺参数为水料比25∶1(mL/g)、纤维素酶添加量3%、水解时间2 h,此条件下豆渣SDF提取率为18.65%。然后通过正交试验优化了用豆渣SDF制备可食用膜的配方为SDF 1.0 g、甘油4.5 g、CMC 1.0 g、海藻酸钠1.5 g。用最优配方制备的可食用膜具有良好的性能:膜厚度0.032 mm、透明度13.26%、溶解速度25 s/g、水蒸气透过系数0.61 g·mm/m^(2)·d·kPa、透油系数4.15 g·mm/m^(2)·d。该研究可为豆渣的深加工提供方法参考,所制备的可食用膜有望用于食品加工、包装行业。

复合酶法提取麦麸SDF优化工艺条件

主要采用淀粉酶、碱性蛋白酶和纤维素酶3种复合酶酶解提取麦麸中可溶性膳食纤维(SDF)。通过研究淀粉酶、碱性蛋白酶和纤维素酶的最佳配比以及各种单因素与麦麸SDF得率的关系,以此为基础,采用正交试验进一步优化复合酶提取麦麸的最佳酶解条件,从而获得得率较高的SDF。结果表明,提取麦麸中SDF的最佳酶解工艺条件为:m(淀粉酶)∶m(碱性蛋白酶)∶m(纤维素酶)=2∶1∶2,复合酶用量质量分数4%,酶解温度60℃,酶解液pH7,酶解时间1.5 h,SDF得率质量分数为18.40%。

发酵法提取梨渣、姜渣和豆渣膳食纤维的分离纯化及表征

目的采用发酵法提取果蔬渣膳食纤维,并对分离纯化后的膳食纤维进行结构表征。方法利用红曲霉发酵梨渣、姜渣和豆渣制备可溶性膳食纤维,采用离子交换层析柱和凝胶层析柱对制备的可溶性膳食纤维进行分离纯化,通过扫描电镜、气相色谱-质谱法和红外光谱等方法进行微观结构、单糖组成和官能团分析,并测定其热特性和抗氧化活性。结果红曲霉发酵后梨渣可溶性膳食纤维、姜渣可溶性膳食纤维和豆渣可溶性膳食纤维产量分别为6.28%、4.50%和7.69%;这些纤维的结构呈疏松多孔状态;主要的组成成分包括鼠李糖、阿拉伯糖、木糖、葡萄糖醛酸、葡萄糖和半乳糖;所有纤维样品在红外光谱图中4000~500 cm‒1范围内均具有多糖的特征吸收峰。此外,这3种果蔬渣可溶性膳食纤维表现出一定的热稳定性和抗氧化能力,其中姜渣可溶性膳食纤维的2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)ammonium salt,ABTS]阳离子自由基清除率和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率分别达到了86.65%和51.61%。结论红曲霉发酵制备的果蔬渣可溶性膳食纤维的各方面理化性质较为优异,在功能性食品领域具有应用潜力。

挤压对柚皮可溶性膳食纤维理化、功能及结构特性的影响

为了探究挤压技术对柚皮可溶性膳食纤维(SDF)理化、功能及结构特性的影响,对柚皮的SDF进行提取后,对SDF进行理化特性、比表面积测定,观察SDF微观结构,进一步测定分析SDF的生物活性。结果表明:与对照组相比,挤压(螺杆转速160 r/min,挤出温度140℃)处理后,SDF的提取得率提高了214%,比表面积增大到原来的1.63倍;持水力、持油力和膨胀力分别提高了13.1%、160.5%和25.1%;葡萄糖吸附能力和阳离子交换能力分别提高了180.3%和70.5%;亚硝酸盐吸附能力在pH为2时提高了19.1%,在pH为7时提高了36.2%;DPPH和ABTS自由基清除率分别提高了88%和22%。挤压处理后SDF的热稳定性更高,结构疏松,表面凹凸不平,颗粒化明显,化学基团暴露数量被改变但未产生新的基团。

豆渣可溶性膳食纤维果蔬保鲜涂膜液的制备及其应用

以豆渣为原料,采用酶法提取可溶性膳食纤维(SDF),再以SDF和壳聚糖为基材,以甘油、醋酸、L-抗坏血酸棕榈酸酯为添加剂制备绿色保鲜涂膜液,研究其对圣女果的保鲜效果。以感官评分为指标,在单因素试验的基础上通过正交试验优化涂膜液的配方。结果表明:最优涂膜液配方为甘油添加量1.50 g、壳聚糖添加量1.25 g、SDF添加量0.35 g、体积分数5%L-抗坏血酸棕榈酸酯溶液添加量1.25 g。在此条件下制得的涂膜液可将圣女果的有效保鲜期延长至15 d,表明豆渣SDF涂膜液对圣女果具有良好的保鲜效果。

青稞酒糟水溶性膳食纤维的提取及其结构研究

以青稞酒糟为原料,采用酶解法提取水溶性膳食纤维。以水溶性膳食纤维得率为指标,通过正交试验优化提取工艺,并对水溶性膳食纤维的结构及性质进行研究。结果表明:最优提取工艺为料液比1∶15(g/mL)、酶解时间90 min、酶解温度60℃、α-淀粉酶添加量1.0%(以青稞酒糟粉质量计),在此条件下青稞酒糟水溶性膳食纤维得率为17.65%±0.26%;该水溶性膳食纤维为纤维素Ⅰ型结构且热稳定性良好,具有较优的物理性质、吸附性质和抑制α-淀粉酶活性的能力。