膳食纤维饱腹感的研究进展

作为食品的重要组成部分,膳食纤维已被认为是第七大营养素,具有重要的生理作用。膳食纤维能促进咀嚼,增加唾液的分泌,结合大量的水而使胃部膨胀,水合后粘度增加能够延缓营养物质的吸收和胃的排空,具有回肠刹车作用从而减慢肠道的蠕动。通过这些作用,膳食纤维能够促进机体产生饱腹感;另一方面,膳食纤维能够调节胃肠道中与饱腹感产生相关的激素的分泌,如胰岛素、饥饿素、胰高血糖素样肽-1(glucagon-like-peptide-1,GLP-1)、胆囊收缩素(cholecystokinin,CCK)和YY肽(peptide YY)等。本文概述了膳食纤维饱腹感的研究现状,主要包括膳食纤维对饱腹感的影响、饱腹感的生理指标和主观饱腹感的检测方法等方面。     

水溶性与水不溶性膳食纤维对油脂、胆固醇和胆酸钠吸附作用研究

采用离体实验模拟人体胃和肠道的pH环境,探讨了小麦纤维,大豆纤维,水果纤维以及由三者和低聚果糖组成的复合膳食纤维产品分别对油脂,胆固醇,胆酸钠的吸附能力,为功能性复合膳食纤维产品的研发提供依据。结果表明,对不饱和脂肪花生油的吸附能力表现为小麦纤维2．68g／g〉清多冲剂2．3sg／g〉大豆纤维1．76g／g～水果纤维1．66g／g;对饱和脂肪猪油的吸附能力表现为小麦纤维5．64g／g〉清多冲剂5．37g／g〉大豆纤维5．14g／g～水果纤维4．S7g／g。对胆固醇和胆酸钠的吸附,水果纤维能力最强,分别为11．34g／g和73．70mg／g,清多冲剂次之中,其吸附量为9．23g／g和45．37mg／mL;均高于小麦纤维和大豆纤维。另外,在胃pH条件下,几种膳食纤维对胆固醇的吸附能力显著低于在肠道pH条件下。实验结果说明,复合膳食纤维产品“清多冲剂”能综合三种单一种类膳食纤维的优点。     

双蛋白营养代餐粉的配制及其品质特性分析

以双蛋白营养粉为基料，以高纤膳食组合（魔芋粉、奇亚籽、菊粉）、麦芽糊精以及果粉为原料，研制一款高蛋白、高纤维、易饱腹、脂肪含量低、营养丰富的双蛋白营养代餐粉。对高纤膳食组合的粉碎方式及混料配方进行探究，发现三种原料按比例混合球磨产物得率高、颜色较浅、颗粒均匀；通过单因素实验和正交试验对代餐粉配方进行优化设计，得到最佳配方为:双蛋白营养粉添加量74%，高纤膳食组合添加量12.3%，麦芽糊精添加量8.5%和果粉添加量5.2%，此组合的代餐粉香气浓郁、入口顺滑、细腻，能够快速溶解。对该组合代餐粉的营养成分和粉体特性进行分析，结果表明，所制代餐粉蛋白含量明显高于市售同类产品（每100 g双蛋白营养代餐粉蛋白含量高达39 g），营养丰富，流动性好，无强烈飞溅性倾向，符合国际和国内相关标准。本研究为我国代餐粉行业发展提供了新的方向。     

体外结肠发酵对青稞膳食纤维中酚类化合物的含量及抗氧化活性的影响

以青稞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)为原料,通过体外结肠发酵,测定不同时间点酚类化合物的含量和抗氧化活性,并利用高效液相色谱法对发酵液中的酚类化合物进行定性和定量。结果表明:在体外结肠发酵48 h过程中,随着发酵时间的延长,IDF中酚类化合物含量呈逐渐升高趋势,SDF中酚类化合物含量呈先升高后下降趋势,在结肠发酵第30小时,酚类化合物含量达到最高,为(50.62±2.45)μmol/g;IDF和SDF中酚类化合物的抗氧化活性变化趋势与酚类化合物含量变化相似;青稞膳食纤维经体外结肠发酵后,发酵液中酚类化合物分为羟基苯甲酸、羟基肉桂酸和类黄酮,包括18种酚类化合物。在结肠发酵过程中,IDF和SDF中阿魏酸含量均呈先升高后下降趋势,IDF在发酵第24小时含量最高;SDF在发酵第5小时含量最高。结果表明,青稞膳食纤维可作为多酚的传递物质,在结肠发酵过程中缓慢释放多酚化合物,能够提高多酚含量和抗氧化活性,促进人体健康。     

A comparison of satiety, glycemic index, and insulinemic index of wheat-derived soft pretzels with or without soy

The consumption of nutrient-poor snack foods in Western diets is thought to be contributing to the increasing prevalence of obesity and diabetes. Soy offers unique potential to provide high quality protein, dietary fiber, and phytochemicals to snack foods to produce a more healthful nutritional profile. In this study, 27.3% of wheat flour was replaced with soy ingredients in a soft pretzel and evaluated for impact on satiety, glycemic index (GI), and insulinemic index (II). We first tested the soy pretzel for consumer acceptability by 51 untrained sensory panelists on a 9-point hedonic scale. Second, in a crossover trial, 20 healthy adults consumed soy and traditional pretzels (1000 kJ or 239 kcal each) after an overnight fast. They reported their levels of satiety on a 10 cm visual analog scale (VAS) for 2 h postprandially. Third, 12 healthy, non-diabetic subjects consumed soy or traditional pretzels (50 ± 2 g available carbohydrates) to determine the GI and II of both products. Blood glucose and insulin responses were monitored for 2 h after consumption and compared to a glucose reference. It was found that a consumer-acceptable soy soft pretzel had a lower mean (±SD) GI than its traditional counterpart: 39.1 (±20.4) for soy and 66.4 (±15.3) for wheat, (p = 0.002). However, soy addition did not statistically affect II (p = 0.15), or satiety (p = 0.91). In conclusion, a nutrient-dense soy pretzel formulation with 27.3% of wheat flour replaced by soy ingredients had attenuated postprandial glycemia without significantly affecting insulinemia or satiety in healthy adults.     

基于非水溶性膳食纤维介质的双歧杆菌生物膜动态培养及其抗逆性研究

本文旨在研究动态培养下双歧杆菌在不同非水溶性膳食纤维介质表面的成膜差异及生物膜抗逆特性。基于生物膜的成膜活菌数及扫描电镜结构表征,比较双歧杆菌在6种非水溶性膳食纤维的成膜情况,结果发现双歧杆菌在葡萄籽粉上成膜能力最强,其次是在小麦纤维上。进一步研究双歧杆菌在不同载体上的最佳成膜时间,结果发现在葡萄籽粉界面的最佳成膜时间为36 h,基于小麦纤维的最佳成膜时间为24 h。比较生物膜成膜菌株和浮游菌株在冻干存活率和模拟胃肠液耐受性的差异性,研究显示生物膜成膜菌株较浮游菌株冻干存活率提高4~6.5倍(P<0.01),在模拟胃肠道耐受性试验中,模拟胃液耐受性提高了5.1~5.9倍(P<0.01),最高存活率达到59.82%±2.32%,模拟肠液耐受性提高了10~12.6倍(P<0.01),最高存活率达到13.53%±1.5%。这些结果表明虽然双歧杆菌在不同非水溶性膳食纤维上形成生物膜能力和成膜时间不同,形成生物膜后其抗逆性显著提高。这一研究结果为开发抗逆性益生菌制剂提供了理论基础。     

影响饱腹感的成分及其生理功能的研究进展

摄食是是影响人们在短期内的能量获取的重要因素。过度的食物摄入造成人体非必需能量增加,引发肥胖、糖尿病、冠心病等疾病。为改善营养过量摄入现状,人们通过产生自身饱腹感来降低食物摄入量。有研究表明,含有膳食纤维,淀粉,蛋白质的食物摄入后会产生强烈饱腹感,能够有效减少能量摄入,但是人们却对其中的机制知之甚少。本文主要对人体饱腹感产生机理、产生饱腹感的物质种类(膳食纤维,淀粉,蛋白质)及其生理功能进行论述,旨在为人类健康饮食和预防疾病的研究提供思路。     

七种药食两用中药膳食纤维体外抗氧化及胆酸盐结合能力研究

为了探究药食两用中药膳食纤维的生理活性,选择党参、黄芪、山药、甘草、灵芝、人参、西洋参七种药食两用中药制备了水溶性膳食纤维（soluble dietary fiber,SDF）、非水溶性膳食纤维（insoluble dietary fiber,IDF）和总膳食纤维（total dietary fiber,TDF）,并对其体外抗氧化活性和胆酸盐结合能力进行了研究。结果表明:七种膳食纤维成分的理化性质和体外活性存在显著差异。党参、灵芝和人参TDF分别具有最高的持水性（11.26 g/g）,持油性（6.36 g/g）和溶胀性（9.12 mL/g）。黄芪SDF、山药SDF和西洋参TDF分别具有最高的DPPH自由基清除率（96.27%）,羟自由基清除率（97.20%）和超氧阴离子自由基清除率（60.32%）,人参TDF的总抗氧化能力最强（2283.39 μmol/L/FeSO₄）。人参TDF对甘氨胆酸钠结合率最高（59.87%）,黄芪TDF对牛磺胆酸钠结合率最高（51.52%）,七种药食两用中药膳食纤维对甘氨胆酸钠的平均结合率（34.12%~53.73%）高于对牛磺胆酸钠的平均结合率（28.16%~45.47%）。本研究证实了党参等七种药食两用中药膳食纤维具有良好的理化性质和生理活性,具有功能性食品的开发潜力。     

膳食纤维吸附脂肪、胆固醇和胆酸盐的研究

采用离体实验模拟人体胃和肠道的pH环境,探讨了大豆纤维、小麦纤维、水果纤维以及由3者和低聚果糖组成的复合膳食纤维产品“清多冲剂”的持水力、对脂肪、胆固醇、胆酸盐的吸附能力,为功能性复合膳食纤维产品的研发提供依据。结果表明,对花生油的吸附能力表现为小麦纤维2.68g/g>清多冲剂2.35g/g>大豆纤维1.76g/g～水果纤维1.66g/g;对猪油的吸附能力表现为小麦纤维5.64g/g>清多冲剂5.37g/g>大豆纤维5.14g/g～水果纤维4.57g/g。对胆固醇和胆酸的吸附,水果纤维能力最强,分别为11.34g/g和73.70mg/g,复合膳食纤维产品“清多冲剂”次之,其吸附量为9.23g/g和45.37mg/mL;两者的吸附能力都大大高于小麦纤维和大豆纤维的吸附能力。另外,在胃pH条件下,几种膳食纤维对胆固醇的吸附能力显著低于在肠道pH条件下。实验结果说明,复合膳食纤维“清多冲剂”能综合3种单一种类膳食纤维的优点。     

菌质水溶性膳食纤维对小鼠肠蠕动与吸收的影响

研究菌质水溶性膳食纤维对小鼠肠蠕动与吸收的影响,为其在食品工业和医药保健领域应用提供理论依据。选取75只昆明种小鼠,随机分成5组:空白对照组、阳性对照组和3个受试组,分别灌胃生理盐水、50 mg/kg·BW的酚酞溶液、2.5g/kg·BW的水溶性膳食纤维、5g/kg·BW的水溶性膳食纤维、15g/kg·BW的水溶性膳食纤维。试验时间共13d,每天记录小鼠体重,小鼠小肠吸收试验和蠕动试验分别测定计算血清中木糖浓度、碳末推进率。结果表明:1菌质水溶性膳食纤维具有一定的抑制小鼠体重的作用(P0.05),且抑制小鼠体重与菌质水溶性膳食纤维剂量呈正相关(P0.05);2中剂量的菌质水溶性膳食纤维组小鼠小肠吸收功能的影响达显著水平(P0.05);3菌质水溶性膳食纤维能促进小鼠小肠蠕动(高、中剂量达到极显著水平,P0.01;低剂量达到显著水平,P0.05),且小鼠小肠蠕动与菌质剂量呈正相关性(高剂量与低剂量的菌质水溶性膳食纤维组之间差异显著,P0.05)。因此,一定量的菌质水溶性膳食纤维能抑制小鼠体重,具有促进小鼠小肠蠕动与吸收的作用。     

A low-calorie beverage supplemented with low-viscosity pectin reduces energy intake at a subsequent meal

The addition of fiber to foods and beverages has been linked with greater satiety and reduced energy intakes at the next meal. However, measures of satiety can be influenced by the time interval between beverage consumption and the next meal. The objective of this study was to determine how the time interval between consumption and a subsequent test meal impacts the satiating power of a low-calorie beverage supplemented with low-viscosity pectin fiber. Forty-two participants (20 men, 22 women) each participated in 4 study sessions. Study preloads were 2 low-calorie beverages (355 mL, 8 kcal) containing either 0 g fiber (no fiber) or 8 g low-viscosity fiber (added fiber). These preloads were consumed either 90 min before lunch or 15 min before lunch. Every 15 min, participants rated hunger, desire to eat, fullness, and thirst using 100-mm visual analogue scales. A test lunch was served and plate waste was measured. Beverages with added fiber reduced energy intakes at lunch relative to those without fiber. A short delay (15 min) between beverage consumption and a subsequent meal was associated with higher satiety ratings and reduced energy intakes, regardless of fiber content. The addition of low-viscosity pectin to low-calorie beverages reduced energy intakes at the next meal, presenting a possible tool for intake regulation. A short time interval between consumption of a low-calorie beverage and a meal also increased satiety and decreased food intake, reflecting the short-lived effect of volume.     

High Protein Pasta is Not More Satiating than High Fiber Pasta at a Lunch Meal,Nor Does it Decrease Mid‐Afternoon Snacking in Healthy Men and Women

This study compared satiety after high protein pasta (16 g protein, 6 g fiber), high fiber pasta (11 g protein, 8 g fiber) or control pasta (11 g protein, 6 g fiber) in a randomized, placebo‐controlled, double‐blind crossover trial. Participants were 36 healthy and men and women from the University of Minnesota campus. Fasted men and women ate calorie controlled, but macronutrient different pastas at 12:00 pm along with 500 mL of water. The primary outcome was satiety assessed by Visual Analogue Scales at 0, 15, 30, 45, 60, 90, 120, and 180 min daily after consuming the pastas. Secondary outcomes were calories consumed at an ad libitum snack at 3:00 pm, calories from food intake, gastrointestinal tolerance, and palatability. No differences were found among the pasta treatments for satiety, snacking, or gastrointestinal tolerance. Men ate significantly more calories for the rest of the (P = 0.007) after the high protein pasta versus the high fiber pasta (1701 ± 154 compared with 1083 ± 154) with control pasta being intermediate to the other treatments. No significant differences were found for gastrointestinal tolerance, but the palatability ratings showed the high protein pasta was less tasty (P = 0.03) and less pleasant (P = 0.01) than the other 2 pastas. Satisfaction was positively associated with pleasantness and negatively associated with aftertaste. Our results do not support the idea that high protein or high fiber pasta produces a greater satiety response compared to pasta with lower amounts of either nutrient. It is likely that since pasta is already a very satiating food, the subjects were unable to differentiate between the 3 conditions.     

不溶性大豆膳食纤维对大鼠采食行为及血液指标的影响

以Wistar大鼠为实验动物,喂食普通饲料,同时灌胃不溶性大豆膳食纤维,观察大豆膳食纤维对大鼠体重、血液中维生素A和钙离子的影响。结果发现,大鼠摄入大豆膳食纤维后,采食行为受到抑制,饱腹感增加,且大鼠体重增长受到抑制,达到控制体重的效果,然而大鼠血液中的维生素A和钙离子含量有所降低,其中大鼠每日摄入500 mg/kg膳食纤维,至第55天时,大鼠体重仅占空白组体重的78.38%,同时,血液中的维生素A降低了35.80%,钙离子降低了51.21%。     

枣渣中可溶性膳食纤维的提取

试验以枣渣为原料,分别采用稀盐酸酸解、高压蒸煮和超声分散进行预处理,再用纤维素酶进行酶解提取膳食纤维,根据可溶性膳食纤维(SDF)和不溶性膳食纤维(IDF)得率来选择最佳可溶性膳食纤维提取方法。结果表明:枣渣经121℃,0.1 MPa高压蒸煮30 min后,再加0.5%的纤维素酶水解,SDF的得率达11.3%。和其它方法相比,该工艺过程的水解得率最高。     

Dietary fiber intake reduces risk for Barrett's esophagus and esophageal cancer

Background: Observational studies suggest an association between dietary fiber intake and risk of Barrett's esophagus and esophageal cancer. However, the results are inconsistent. Objective: To conduct a meta-analysis of observational studies to assess this association. Design: All eligible studies were identified by electronic searches in PubMed and Embase through February 2015. Dose–response, subgroup, sensitivity, and publication bias analyses were performed. Results: A total of 15 studies involving 16,885 subjects were included in the meta-analysis. The pooled odds ratio for the highest compared with the lowest dietary fiber intake was 0.52 (95% CI, 0.43–0.64). Stratified analyses for tumor subtype, study design, geographic location, fiber type, publication year, total sample size, and quality score yielded consistent results. Dose–response analysis indicated that a 10-g/d increment in dietary fiber intake was associated with a 31% reduction in Barrett's esophagus and esophageal cancer risk. Sensitivity analysis restricted to studies with control for conventional risk factors produced similar results, and omission of any single study had little effect on the overall risk estimate. Conclusions: Our findings indicate that dietary fiber intake is inversely associated with risk of Barrett's esophagus and esophageal cancer. Further large prospective studies are warranted.     

Resistant starch—An accessible fiber ingredient acceptable to the Western palate

Dietary fiber intakes in Western societies are concerningly low and do not reflect global recommended dietary fiber intakes for chronic disease prevention. Resistant starch (RS) is a fermentable dietary fiber that has attracted research interest. As an isolated ingredient, its fine particle size, relatively bland flavor, and white appearance may offer an appealing fiber source to the Western palate, accustomed to highly refined, processed grains. This review aims to provide a comprehensive insight into the current knowledge (classification, production methods, and characterization methods), health benefits, applications, and acceptability of RS. It further discusses the present market for commercially available RS ingredients and products containing ingredients high in RS. The literature currently highlights beneficial effects for dietary RS supplementation with respect to glucose metabolism, satiety, blood lipid profiles, and colonic health. An exploration of the market for commercial RS ingredients indicates a diverse range of products (from isolated RS2, RS3, and RS4) with numerous potential applications as partial or whole substitutes for traditional flour sources. They may increase the nutritional profile of a food product (e.g., by increasing the fiber content and lowering energy values) without significantly compromising its sensory and functional properties. Incorporating RS ingredients into staple food products (such as bread, pasta, and sweet baked goods) may thus offer an array of nutritional benefits to the consumer and a highly accessible functional ingredient to be greater exploited by the food industry.     

从甘薯渣发酵醪液中制备的膳食纤维的物化特性研究

以甘薯渣酒精发酵后的醪液为原料,采用物理筛分法制备膳食纤维。测定酒精发酵醪液制备的膳食纤维(AFDF)的化学组成成分、显微结构、色泽、粒度、吸水膨胀性、持水性和持油性,并分别与甘薯膳食纤维(SPDF)、大豆膳食纤维(SDF)和燕麦膳食纤维(ODF)进行比较。结果表明:AFDF纯度最高,为82.46%,其显微结构为多孔状,粒径在1～60μm范围内,具有较好的吸水膨胀性(13.26mL/g)、持水性(11.84g/g)和持油性(1.85g/g),因而是一种潜在可利用的膳食纤维资源。     

Superheated steam processing of oat groats

Superheated steam (SS) processing of oat groats with a lab-scale SS processing system was studied as a method of heat treatment alternative to commercial processing (kiln drying) of groats. The objective of this study was to determine conditions of SS processing necessary to obtain groats with inactivated peroxidase, moisture content and colour comparable to commercially processed groats, but with pasting properties unique to those obtained in commercial processing. Raw or moisture tempered oat groats (∼13 g) were processed with SS at varying processing times (1-30 min) depending on steam temperature (110-160 °C) and velocity (0.35 and 1.00 m/s) used. Generally, groats processed with SS exhibited higher cold paste (64 °C) viscosity than the groats processed commercially. Oat groats processed with SS to final moisture content of 9-10/100 g (wet basis, wb) or less were peroxidase negative. The parameters of SS selected for processing of oat groats were: temperature of 110 °C, a velocity of 1.00 m/s, and two processing times (10 and 14 min). These parameters gave groats with inactivated peroxidase, moisture content at ∼9.5/100 g (wb), significantly (P < 0.05) brighter colour, and significantly higher cold paste viscosity compared to that of groats processed commercially.     

Grape antioxidant dietary fiber stimulates Lactobacillus growth in rat cecum

The digesta is a highly active biological system where epithelial cells, microbiota, nondigestible dietary components, and a large number of metabolic products interact. The gut microbiota can be modulated by both endogenous and exogenous substrates. Undigested dietary residues are substrates for colonic microbiota and may influence gut microbial ecology. The objective of this work was to study the capacity of grape antioxidant dietary fiber (GADF), which is rich in polyphenols, to modify the bacterial profile in the cecum of rats. Male adult Wistar rats were fed for 4 wk with diets containing either cellulose or GADF as dietary fiber. The effect of GADF on bacterial growth was evaluated in vitro and on the cecal microbiota of rats using quantitative real time polymerase chain reaction (RT-PCR). The results showed that GADF intake stimulates proliferation of Lactobacillus and slightly affects the composition of Bifidobacterium species. GADF was also found to have a stimulative effect on Lactobacillus reuteri and Lactobacillus acidophilus in vitro. These findings suggest that the consumption of a diet rich in plant foods with high dietary fiber and polyphenol content may enhance the gastrointestinal health of the host through microbiota modulation. PRACTICAL APPLICATION: Grape antioxidant fiber combines nutritional and physiological properties of dietary fiber and natural antioxidants from grapes. Grape antioxidant fiber could be used as an ingredient for functional foods and as a dietary supplement to increase the intake of dietary fiber and bioactive compounds.     

Influence of depigmentation of pearl millet (Pennisetum gluacum L.) on sensory attributes, nutrient composition and in vitro digestibility of biscuits

Presence of high concentration of pigments in the pericarp and endosperm regions of pearl millet imparts undesirable gray color to its products. This study attempts to improve the acceptability of pearl millet products through processing technique and to study its effect on nutritional composition of pearl millet product. Pearl millet grains were depigmented by soaking in 0.2 N HCl for 18 h followed by washing, blanching at 98°C for 30 s and sun drying. Three different types of biscuits were prepared from refined flour (Reference), native or unprocessed pearl millet (T-I) and depigmented pearl millet (T-II). Results indicated that depigmentation improved the sensory attributes especially the color of pearl millet biscuits (T-II). The protein, fat, ash and total dietary fiber of pearl millet based biscuits (T-I as well as T-II) were significantly (P?0.05) higher than the reference biscuits. Depigmentation significantly improved the in vitro starch digestibility, in vitro protein digestibility and the soluble dietary fiber content of pearl millet biscuits (T-II) by 14.50, 6.56 and 6.18%, respectively. On the other hand, a significant decrease of 6.73, 2.43 and 17.03 g/100 g in protein, starch and insoluble dietary fiber was detected in pearl millet biscuits (T-II) due to depigmentation.