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.

Effect of wheat bran insoluble dietary fiber with different particle size on the texture properties, protein secondary structure, and microstructure of noodles

This study was conducted to explore how the insoluble dietary fiber(IDF)of wheat bran with different particle size affects the texture properties,water distribution,protein secondary structure and microstructure of noodles.The results suggested that IDF addition increased the cooking loss and decreased the sensory evaluation because of the damage on dough structure,while as the IDF particle size decreased,the sensory score increased from 78.8 to 82.3 and cooking loss decreased from 8.65%to 7.65%,which could be attributed to that small particle-sized IDF limited the damage on protein network structure,decreased the T22 and t-structure,and increased the β1-structure.Moreover,IDF particle size had a significant correlation with protein secondary structures,texture properties and evaluation score of noodles.In conclusion,adding appropriate particle sizewould be an effectiveway of enhancing the nutritional and textural properties of noodles.

Effects of insoluble dietary fiber from wheat bran on noodle quality

Benefiting from its favorable effects in promoting intestinal peristalsis,increasing satiety and reducing postprandial blood sugar,wheat bran insoluble dietary fiber(IDF)could be added to noodles to improve the nutrition value of noodle products.However,the addition of IDF usually results in an adverse effect on the quality characteristics of fiber fortified products,leading to unfavorable texture and consumption drop.It was found that IDF could weaken dough characteristics,thereby causing the quality deterioration of noodles,but the mechanism is unclear as yet.This study aimed to investigate the effects of different amounts of IDF on the texture quality and cooking quality of noodles.The water distribution,rheological properties,pasting properties and cooking properties of the noodles were determined by low-field nuclear magnetic resonance(LF-NMR),dynamic rheometer,and rapid visco-analyzer.The results of the LF-NMR showed that the increased IDF in the noodles resulted in a contraction of relaxation time and an increase in the proportion of loosely bound water.At a high amount of IDF,the water absorption and tensile distance of the noodles significantly decreased and the cooking loss rate increased,with a downward trend in peak viscosity,final viscosity and setback values.Moreover,IDF could improve the storage modulus and loss modulus of sheeted dough and enhance the texture of noodles.Furthermore,the correlations between IDF addition amounts and rheological properties as well as cooking properties were analyzed,and the results confirmed that noodles with the IDF amount of 2%–4%had higher nutrition and quality.This study provides the basis for future development and improvement of IDF-enriched health foods.

芹菜IDF与多菌群益生菌连续共培养的培养物特性

该研究利用生物膜富集微生物的原理,以芹菜中的水不溶性膳食纤维(insoluble dietary fiber,IDF)为载体,保加利亚乳杆菌Lactobacillus bulgaricus(Lb G302)、植物乳杆菌L. plantarum(Lp G304)、副干酪乳杆菌L. paracasei(Lcp G305)、鼠李糖乳杆菌L. rhamnosus(Lr G306)、嗜热链球菌Streptococcus thermophilus(St Q305)为菌株,MRS为营养液,在自主设计的富集培养装置中,富集芹菜IDF中多菌群益生菌,形成富含芹菜IDF与多菌群益生菌的生物膜培养物,研究该生物膜培养物的活菌数、菌群结构、代谢物组成、对消化液的耐受性以及抗氧化活性等。结果表明,37℃富集培养7 d,活菌数可达7.5×10^(13)CFU/g;扫描电镜显示芹菜IDF上形成了较厚的生物膜;0~7 d的Illumina NovaSeq高通量测序分析表明,所接种的乳杆菌和链球菌均被检出;7 d的代谢组学分析结果显示,检出的代谢物有1 398种,其中主要功能物质有神经递质、维生素和辅酶类、肽类等;对DPPH自由基的清除率达到95%以上;经消化液处理后,其活菌数维持在10^(11)CFU/g。

Extraction, Purification, and Characterization of Insoluble Dietary Fiber from Oat Bran

The dietary fiber in oats is mainly concentrated in the bran;however,the oat bran is mostly used for livestock and poultry feed and thus has a low utilization rate and low added value.In this study,insoluble dietary fiber(IDF)was extracted by a combination ofα-amylase and neutral protease.The optimal extraction conditions of the IDF were obtained by response surface methodology.The material-to-water ratio was 1:12.1,the concentration ofα-amylase was 1.85%,and the hydrolysis time was 39.14 min.After purifying the crude fiber with 4%sodium oxide(Na OH),70°C hot water,and anhydrous ethanol,the purity of dietary fiber exceeded 95%.X-ray diffraction analysis indicated that the IDF was predominantly amorphous.Scanning electron microscopy showed that the IDF surface exhibited a loose porous network structure.Fourier-transform infrared spectroscopy of the crude IDF showed characteristic absorption peaks at 3626,2929,1667,1538,1455,1242,and1048 cm^(-1),while the infrared spectrum of the purified IDF showed characteristic absorption peaks at 3401,2924,1744,1643,1418,and 1040 cm^(-1),which is consistent with the structure of cellulose polysaccharide.Differential scanning calorimetry analysis showed that there were three exothermic peaks at 270–310°C,320–350°C,and 440–460°C,which may represent the pyrolysis peaks of hemicellulose,cellulose,and lignin,respectively,indicating that the oat bran IDF had good thermal stability.The results indicate that the oat bran IDF can be used for the production of dietary fiber products and health-care products.

Study on Extraction of Insoluble Dietary Fiber from Apple pulp

[ Objective] To optimize the extraction conditions of insoluble dietary fiber from apple pulp. [ Method] The insoluble dietary fiber was ex-tracted from the apple pulp by alkaline, and the optimal extraction conditions were determined by orthogonal experiment. [ Result] The influential or-der of each factor on the extraction of insoluble fiber decreased in the order of solid-liquid ratio 〉 alkali concentration 〉 temperature 〉 extraction time, and the optimal extraction technology was A3 B1 C2 D2, that is, 1：11 （g/ml） of solid-liquid ratio, 0.25 mol/L alkaline concentration, 50 ℃ of extraction temperature and 2.0 h extraction time, under these conditions, the yield of insoluble dietary fiber was 35.46%. [ Conchsion] The apple pulp contains rich dietary fiber, and the insoluble dietary fiber extracted from the apple pulp has great development value. Key words Apple; Insoluble dietary fiber; Extraction technology; China

Effects of different ratios of soluble to insoluble dietary fiber on growth performance and intestinal health of piglets

This study investigated the impact of different ratios of soluble to insoluble dietary fiber(SDF:IDF)formulations by sugar beet pulp(SBP)supplementation on piglet growth performance,nutrient digestibility,immune function,intestinal morphology,intestinal microbiota and intestinal health.A total of 60 crossbred piglets(Duroc×[Landrace×Yorkshire])at 40 d old with body weight of 10.0±0.3 kg were randomly assigned to 5 treatments with 6 replicates per treatment and 2 piglets per replicate in a 21-d trial.The dietary treatments included a corn-soybean meal diet(0%SBP supplementation;CON),and diets supplemented with 2%,4%,6%,and 8%SBP,representing different SDF:IDF ratios at 10.16%,13.53%,16.79%,19.86%,and 24.81%,respectively.The results indicated that the 8%SBP treatment had a negative effect on feed-to-gain ratio(linear,P=0.009)compared with the CON treatment(P=0.021).The apparent total tract digestibility(ATTD)of crude protein was lower in treatments supplemented with SBP(P=0.002)and showed a linear decrease(P=0.001),while the ATTD of IDF showed a linear increase(P=0.037)in four SBP treatments compared to the CON treatment.The 4%SBP treatment increased serum concentrations of triglyceride(quadratic,P=0.019)and K(linear,P<0.0037),and decreased alanine transaminase concentration(quadratic,P=0.015)compared with the CON treatment.The concentrations of Cit,Cys,Ile,Leu,Orn,Arg,taurine,urea,1-methylhistidine,α-aminoadipic acid,α-aminobutyric acid and cystathionine in the 4%SBP treatment were highest among all treatments(P<0.05).The serum concentrations of interleukin-6,interleukin-8,interleukin-10,transforming growth factor-β,and tumor necrosis factor-αin the 6%SBP treatment were higher than those in the CON treatment(P<0.05),which also increased mucin-2 and G protein-coupled receptor 41 mRNA expression(P<0.05)in colonic mucosa compared with the CON treatment and improved the intestinal barrier function.Diets containing more than 19.86%SDF:IDF could impair the intestinal health in piglets when SBP was used as the SDF source.Supplementing nursery piglet diets with 16.79%to 19.86%SDF:IDF is recommended for improving intestinal barrier function,increasing short-chain fatty acids concentrations,and improving intestinal microbiota composition.

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.

玉米须不溶性膳食纤维分析及其对面包品质和消化特性的影响研究

首先分析玉米须不溶性膳食纤维(corn silk insoluble dietary fiber,CSIDF)的组分和物理特性,再研究其添加量及粒径对面包比容、色泽、质构、孔隙度、感官等品质和消化特性的影响。结果表明,其主要含80.64%膳食纤维和10.15%蛋白质,以及少量的灰分和脂肪,主要由50.41%纤维素和28.80%半纤维素组成,具有良好的持水、持油和膨胀特性,且粒径越大,3种特性越好;添加玉米须不溶性膳食纤维后面包比容减小,色泽加深,硬度增大,孔隙度降低,不同CSIDF添加量及粒径间存在差异,面包品质与CSIDF添加量及粒径基本呈现负相关,综合分析确定粒径最小的D_(1)(平均粒径为24.91μm)最适宜添加,其添加量为3%时较合适;体外消化试验表明,CSIDF可以通过降低面包中RDS含量、提高SDS和RS含量来延缓淀粉的消化吸收,维持血糖稳定。

柚子皮不溶性膳食纤维的提取工艺优化及特性分析

为获得复合酶法制备柚子皮不溶性膳食纤维的制备工艺及其吸附特性,实验以柚子皮为原料,采用正交试验优化提取柚子皮不溶性膳食纤维(IDF),并对其特性进行研究。结果表明,料液比1:40 g/mL、淀粉酶的添加量0.6%、淀粉酶的酶解时间90 min、木瓜蛋白酶的添加量0.2%、木瓜蛋白酶的酶解时间30 min为最佳提取条件,该条件下柚子皮IDF得率为55.07%。柚子皮IDF的膨胀力、持水力、持油力和阳离子交换能力分别为2.84±0.09 mL/g、12.54±0.11 g/g、1.54±0.02 g/g和0.36±0.04 mmol/g。此外,体外吸附研究表明,柚子皮IDF对葡萄糖、胆固醇、胆酸钠的吸附能力分别为0.13±0.003 mmol/g、12.27±0.020 mg/g和53.25±0.100 mg/g。FT-IR分析表明,柚子皮IDF具有纤维素类多糖的特征吸收峰,符合膳食纤维的结构。综上,优化工艺后提取的柚子皮IDF具有较好的特性,这为进一步开发利用柚子皮IDF提供了理论依据。

粒径和含结合酚不溶性膳食纤维对白芸豆皮体外发酵特性的影响

为揭示不同粒径的白芸豆皮和含结合酚不溶性膳食纤维的体外发酵规律,本研究以白芸豆皮(WS)为原料,经过连续酶法提取得到含结合酚不溶性膳食纤维(IB),采用普通粉碎和超微粉碎方法对其进行改性,获得不同粒径分布的两组样品,利用扫描电子显微镜和激光共聚焦扫描显微镜对其微观形貌进行观察,并通过体外发酵实验和16S rRNA测序探究两组样品的酵解特性及其对肠道菌群组成丰度的影响。实验结果发现样品粒径越小,结合酚越均匀地分散于颗粒表面。WS和IB都具有慢发酵性,且其发酵速率和产酸量均随着粒径的减小而提高,菌群组成分析发现粒径越小的底物对Bacteroides丰度的促进效果也越显著,但是Lachnospira显示出了对较大粒度底物的偏好。结果表明IB可以促进Bacteroides、Bifidobacterium和Ruminococcaceae ruminococcus等有益菌的相对丰度,改善肠道微生物群的组成结构,其益生效应较相同粒径的WS更为显著。本研究可以为膳食纤维益生元效应的研究提供基础和方向,并可以指导膳食纤维的超微粉碎改性和白芸豆皮的综合利用。

菠萝果渣中不溶性膳食纤维提取工艺优化及其功能特性研究

以菠萝果渣为原料,采用碱处理法提取菠萝不溶性膳食纤维(PIDF)。以PIDF得率为指标,在单因素试验基础上通过响应面法优化提取工艺,并探究PIDF的结构和功能特性。结果表明:最优工艺参数为液料比26∶1(mL/g)、NaOH体积分数6%、提取温度40℃、提取时间75 min,在此条件下PIDF得率为48.81%;PIDF具有疏松的孔洞结构,其持水性、持油性和膨胀性分别为(5.16±0.21)g/g、(3.86±0.11)g/g和(5.49±0.09)mL/g,表明PIDF具有较好的结构及功能特性。

三种食物来源膳食纤维的理化性质与功能特性比较

为探究不同来源膳食纤维吸附能力的差异,本研究以柚子、胡萝卜和米糠来源的不溶性膳食纤维为研究对象,比较分析了其显微结构特征、理化特性,胆酸钠吸附力与释放动力学、胆固醇吸附力、葡萄糖吸附力和亚硝酸盐清除能力等吸附特性。结果显示:胡萝卜膳食纤维是表面较光滑的球形颗粒,具有最佳的吸水膨胀力(7.92 mL/g)、胆汁酸吸附力(57.80 mg/g)与模拟肠环境(pH值7)时的胆固醇吸附力(11.72 mg/g);米糠膳食纤维呈现出粗糙多孔的不规则结构,拥有最佳的持油力(3.00g/g)、葡萄糖吸附力(20.67mmol/g)、亚硝酸盐吸附力1482.22μg/g(pH值7),2836.23μg/g(pH值2)、胆汁酸阻滞力(4.47 mg/g)和模拟胃环境(pH值2)时的胆固醇吸附力(8.56 mg/g);柚子膳食纤维表现为层叠的鳞片状结构,具有最佳的持水力(15.48g/g)、黏度和优异的胆汁酸阻滞力(3.55 mg/g)。可见,三种不同来源的膳食纤维的显微结构与理化特性各具特点,使三者的吸附特性各具差异。上述研究结果为不同种类膳食纤维在健康食品中的加工利用提供了数据支撑。

高温蒸煮结合蜗牛酶法改性葡萄皮不溶性膳食纤维工艺优化及体外降血糖作用

以葡萄皮为原料,采用高温蒸煮结合蜗牛酶法对葡萄皮不溶性膳食纤维(insoluble dietary fiber,IDF)进行改性处理,旨在提高可溶性膳食纤维(soluble dietary fiber,SDF)得率以及改善SDF和IDF的理化性质。研究不同因素对SDF得率的影响,并对改性前后的膳食纤维进行理化指标的测定。结果表明,适宜的改性工艺条件为:蒸煮时间60 min、蒸煮温度120℃、料液比1:25 g/mL、酶添加量3.50%、酶解温度34.0℃、酶解时间55 min,此工艺下SDF得率为10.25%。改性后SDF的持水力、持油力、膨胀力相比改性前SDF分别提高了1.74、1.53、1.13倍,改性后IDF的持水力、持油力、膨胀力相比改性前IDF分别提高了1.01、1.26、1.27倍。与未改性的SDF和IDF相比,改性后的SDF和IDF的结构变得更加疏松,且葡萄糖吸附能力、葡萄糖透析延迟指数和α-淀粉酶的抑制作用均显著(P<0.05)提高,其中改性后的SDF的葡萄糖吸附能力最强,葡萄糖透析延迟指数也均高于其它膳食纤维样品,在8 mg/mL时对α-淀粉酶的抑制率达到最大值(54.71%)。综上,高温蒸煮结合蜗牛酶法改性的葡萄皮SDF和IDF具有更为良好的特性,为改性葡萄皮膳食纤维提供了理论依据。

葛根素-猴头菇不溶性膳食纤维复合微胶囊的制备及理化性质的研究

目的:旨在制备葛根素-猴头菇不溶性膳食纤维复合微胶囊,通过提高其包埋率、抗氧化特性和生物可及性,进而促进葛根素相关产品的研发。方法:采用2.0%卡拉胶、3.0%海藻酸钠、0.5 g猴头菇不溶性膳食纤维、10.0 mg葛根素、5.0%的CaCl2溶液制得葛根素微胶囊(以不添加不溶性膳食纤维作为对照组),计算其包埋率、抗氧化特性、模拟体内消化释放率、生物可及性,并通过扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)观察其微观结构。结果:猴头菇不溶性膳食纤维能够作为葛根素微胶囊的壁材,且包埋率均高于75.8%,最高可达94.66%,葛根素的承载量由空白组的0.60%增加到添加膳食纤维最高可达1.37%;消化前后DPPH、ABTS+两种自由基的清除能力显著低于未添加猴头菇不溶性膳食纤维的葛根素微胶囊(P<0.05),能够达到延缓抗氧化特性的作用;模拟体内消化的研究发现猴头菇不溶性膳食纤维包埋的葛根素(最低为9.46%)相对于游离的葛根素(17.46%)在胃中能够缓慢的释放,在进入肠道后迅速释放出来并大量溶于模拟肠道液中,使得葛根素肠道中的释放率从游离的22.93%增加到添加不溶性膳食纤维的最高可达92.59%,实现肠道的精准释放,显著提高了葛根素的生物可及性,是游离葛根素的2.9~3.9倍;SEM、FT-IR、XRD从微观层面证实超声辅助提取法所得猴头菇不溶性膳食纤维作为葛根素微胶囊的壁材,能够改善对照组微胶囊将葛根素裸露的缺点,使得微胶囊质地更紧密,也证实猴头菇不溶性膳食纤维的包埋使得葛根素的结晶度降低或消失以及葛根素的特征衍射峰发生偏移或减弱,达到良好的包埋效果。结论:添加猴头菇不溶性膳食纤维能够提高葛根素的溶出速率,延缓葛根素抗氧化的时长,实现其在肠道中的定点释放,提高葛根素的生物可及性和生物利用率,可以作为葛根素微胶囊的壁材。

油莎豆不溶性膳食纤维理化性质、结构特征和乳化特性研究

油莎豆是一种优质且有益健康的作物,含有丰富的营养物质。采用酶法提取油莎豆不溶性膳食纤维,以商业化大豆膳食纤维为对照,进行理化性质测定、结构特征和乳化性能研究。结果表明:与大豆膳食纤维相比,油莎豆不溶性膳食纤维具有更好的持水力[(14.45±0.19)g/g]、持油力[(8.21±0.06)g/g]和膨胀力[(14.23±0.12)mL/g]。油莎豆不溶性膳食纤维的体积平均粒径为(64.47±0.18)μm,是大豆膳食纤维体积平均粒径的56.65%。低场核磁结果显示,油莎豆不溶性膳食纤维具有更多的结合水,而大豆膳食纤维中则含有更多的自由水。热重分析表明,与大豆膳食纤维相比,油莎豆不溶性膳食纤维的质量损失较少,热稳定性更好。在乳化性能方面,随着油莎豆不溶性膳食纤维质量分数的增加,其乳液粒径显著性增大;在同等膳食纤维质量分数下,油莎豆不溶性膳食纤维制备的乳液粒径均显著低于大豆膳食纤维制备的乳液粒径,说明油莎豆不溶性膳食纤维制备的乳液稳定性优于大豆膳食纤维制备的乳液。在相同质量分数下,油莎豆不溶性膳食纤维的黏度低于其对应的大豆膳食纤维,但是质量分数4%的油莎豆不溶性膳食纤维制备的乳液的储能模量和损耗模量为最高。研究旨在为油莎豆不溶性膳食纤维的开发利用提供理论依据。

超高压处理对柚皮海绵层不溶性膳食纤维理化性质、结构和抗氧化活性的影响

该研究解析了超高压处理(600 MPa, 15 min)对3种柚皮海绵层不溶性膳食纤维(insoluble dietary fiber, IDF)理化性质、结构以及抗氧化活性的影响规律。结果表明,超高压处理显著提高了3种柚皮海绵层IDF的溶胀力,其中琯溪蜜柚柚皮海绵层IDF的溶胀力(78.03 mL/g)最高。然而过高的压力会严重破坏膳食纤维的内部结构,导致柚皮海绵层IDF持水力和持油力下降。超高压处理后柚皮海绵层IDF微观结构更加疏松,并显著提高了柚皮海绵层IDF葡萄糖、木糖、阿拉伯糖和半乳糖的含量。通过X-射线衍射发现超高压处理后柚皮海绵层IDF的结晶度降低;傅里叶变换红外光谱显示,超高压处理对柚皮海绵层IDF活性基团种类影响较小,但对其特征峰的吸收强度影响较大。此外,柚皮海绵层IDF经超高压处理后ABTS阳离子自由基和DPPH自由基清除率均有所下降,表明其抗氧化活性降低。以上研究结果表明,超高压处理可改变柚皮海绵层IDF的理化性质、结构和抗氧化活性。该研究为柚皮海绵层IDF的多元化利用提供理论和技术支撑。

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。

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～