谷物膳食纤维及其改性产品抑制红肉胆碱代谢研究进展

流行病学研究表明,谷物膳食纤维对慢性代谢性疾病,如肥胖、Ⅱ型糖尿病、心脑血管疾病以及结肠癌等具有预防作用。红肉膳食结构中补充膳食纤维,在提高膳食营养、促进肠道益生菌增殖的同时,可抑制胆碱成分向三甲胺的转化进而减少动脉粥样硬化等潜在疾病的发生。膳食纤维分子结构特征和介观性质会影响其微生物可利用性和作用方式,并影响其在机体内发挥干预功能,因而多元强化方式的定向改性及构效关系的建立对于目标膳食纤维产品的获得至关重要。本文综述了谷物膳食纤维补充调节肠道菌群和宿主效应的作用及膳食纤维的加工改性,对于目标膳食纤维产品的定向控制、传统膳食结构的调整及膳食诱导的疾病的预防具有重要的理论和指导意义。     

谷物膳食纤维抑制红肉胆碱代谢及其加工适应性

流行病学研究表明,谷物膳食纤维对慢性代谢性疾病,如肥胖、Ⅱ型糖尿病、心脑血管疾病以及结肠癌等具有预防作用。在典型红肉膳食结构中补充膳食纤维,在提高膳食营养、促进肠道益生菌增殖的同时,可抑制胆碱成分向三甲胺的转化进而减少动脉粥样硬化等潜在疾病的发生。膳食纤维分子结构特征和介观性质会影响其微生物可利用性和作用方式,并影响其在机体内发挥干预功能,因而多元强化方式的定向改性理论和技术及构效关系的建立对于目标膳食纤维产品的获得至关重要。基于谷物膳食纤维补充与调节肠道菌群和宿主效应的“精准饮食”研究将颠覆传统的红肉膳食营养原则,为 “健康中国”的实施提供坚实健康基础。     

低聚果糖与小麦纤维--复合膳食纤维调节肠道菌群作用的研究

对低聚果糖与小麦纤维复合膳食纤维调节肠道菌群作用进行研究,研究方法依照《保健食品检验与评价技术规范-2003版》之“调节肠道菌群作用检验方法”。结果表明,该复合膳食纤维产品,在15d动物实验和14d人体实验中,双歧杆菌和乳杆菌数量均有极显著增加,摄入该复合膳食纤维产品具有调节肠道菌群的保健作用。     

膳食结构对人体肠道微生物代谢的影响

选择120位志愿者参加试验,任意将其划分成高脂膳食结构组、高糖膳食结构组和高纤维膳食结构组3组,针对每种膳食结构受试者,随机将其划分成对照组和试验组。分析肠道微生物菌群变化,提取DNA,并进行PCR扩增与产物纯化处理,测试生物学指标。研究结果表明,高脂膳食结构能够使人体体重增加,促进肠道有害微生物的代谢,试验组受试者肠道微生物多样性比对照组高;试验组受试者体重明显高于对照组,高糖膳食结构能够令血糖值升高,对照组受试者肠道微生物多样性高于试验组,试验组样本厚壁菌门含量明显高于对照组,而拟杆菌门含量明显低于对照组;高纤维对照组与试验组丰富度、Shannon指数与均匀性无显著性差异,随着高纤维膳食结构处理时间的增加,拟杆菌门以及后壁菌门数量在一定程度上有所升高,而变形菌门细菌数量无显著改变。高脂、高糖膳食结构会促进有害微生物代谢,高纤维膳食结构会促进有益微生物代谢。     

益生菌膳食纤维粉在肠道功能障碍人群中的应用

本研究制备一种益生菌膳食纤维粉,选取20名社区肠道功能障碍自愿者参与试验,研究益生菌膳食纤维粉在肠道功能障碍人群中的应用情况。经过连续3个月的服用,自愿者的肠道功能发生明显改善,其中自愿者肠道动力发生显著提高(P0.05);血液内肠动力相关指标发生显著提高(P0.05);粪便中水分、p H值和脂肪酸含量明显提高(P0.05);肠道菌群中乳酸杆菌和双歧杆菌数量显著升高(P0.05),而肠杆菌、肠球菌和类杆菌数量显著减少(P0.05)。在试验过程中未发生任何不良反应事件,结果表明所制备的益生菌膳食纤维粉安全有效,具有应用价值。     

谷物膳食纤维改性方法及其在食品中的应用研究进展

麸皮、米糠是谷物加工的副产物,其来源广泛且富含膳食纤维,对人体健康有益。但谷物麸皮或米糠中不溶性膳食纤维含量高会导致其本身适口性差。采用挤压膨化、发酵等改性方法可改善麸皮、米糠源膳食纤维的品质,扩大其应用范围。本文综述了谷物膳食纤维的3类改性方法及其对理化、功能特性的影响,以及改性后的谷物膳食纤维在食品中的应用,并对谷物膳食纤维的开发利用前景进行了展望。     

菌质可溶性膳食纤维对肠道菌群体外生长的影响

研究菌质可溶性膳食纤维对肠道菌群体外生长的作用效果,为其在保健食品中的应用提供参考依据。体外试验分为空白对照组和菌质可溶性膳食纤维组的低、中、高浓度组(质量浓度分别为0.6,1.2,2.4 g/100 m L)。用菌落计数法和菌落大小法观察菌质可溶性膳食纤维对大肠杆菌、金黄色葡萄球菌、白色假丝酵母、保加利亚乳杆菌、长双歧杆菌体外生长的影响。结果表明:不同浓度的菌质可溶性膳食纤维对大肠杆菌、金黄色葡萄球菌、白色假丝酵母均有显著的抑制作用(P﹤0.05或P﹤0.01),对保加利亚乳杆菌和长双歧杆菌均有显著的促进作用(P﹤0.05或P﹤0.01),且抑菌效果和促生长效果均随着菌质可溶性膳食纤维浓度的增加而增强。菌质可溶性膳食纤维具有抑制肠道供试有害菌生长和促进肠道供试有益菌生长的作用。     

黑粒小麦麸皮中多种功能成分联合提取技术

为提高彩麦麸皮的综合利用率,采用联合提取法,从黑粒小麦麸皮中依次提取花青素、水溶性戊聚糖、粗膳食纤维、蛋白质、水不溶戊聚糖等功能成分。采用酸化乙醇法提取花青素,在优化最佳条件下,得率最高为13.62%;采用水提法从提取色素后的残渣中提取水溶性戊聚糖,得率最高为1.4%;采用淀粉酶法去除水溶性戊聚糖提取后残渣中的淀粉,得到粗膳食纤维,得率最高为56%;采用碱液浸提法从粗膳食纤维中提取蛋白质和水不溶性戊聚糖,采用Sevage法将蛋白质和水不溶性戊聚糖分离,蛋白质得率为6.2%,水不溶性戊聚糖得率为7.3%。     

谷物戊聚糖国内外研究进展

就戊聚糖在谷物中的分布 ,戊聚糖的分离、分级、纯化方法 ,物理化学特性 ,以及戊聚糖与谷物品质之间的关系进行了综述     

燕麦综合加工技术

燕麦是世界性健康谷物，其富含蛋白、脂肪、膳食纤维、矿物质等营养素，特别是具有降血脂功能的水溶性膳食纤维含量居谷物资源之首，     

膳食纤维分析方法研究进展

膳食纤维作为一种来源丰富的功能性食品原料,具有重要的生理功能——能够降低便秘、结肠癌、肥胖、心血管疾病、糖尿病等慢性病的发病率。文中就膳食纤维分析方法的研究进展进行了综述,介绍了传统的分析方法,以及近红外分析法、尺寸排阻液相色谱法、高效阴离子色谱法等现代仪器分析方法。     

菊粉的特性及在特殊医学用途配方食品中的应用前景

菊粉及其次级酶解产物低聚果糖作为一种天然的膳食纤维,不仅可提供膳食纤维的功效,更可促进有益菌的生长,在预防便秘和腹泻,以及抑制有害发酵产物,预防结肠癌方面起到积极的作用。同时,菊粉还具有提高矿质元素的生物利用率、降血糖、降血脂及控制体质量等特性,在预防和控制肠道疾病、肥胖病、糖尿病和心血管病等慢性疾病方面有很好的作用。该文综述了菊粉理化性质、生理功能、安全性评价及在特殊医学用途配方食品中的应用前景。     

Alginate as a source of dietary fiber

Alginate, an algal polysaccharide, is widely used in the food industry as a stabilizer, or as a thickening or emulsifying agent. As an indigestible polysaccharide, alginate may also be viewed as a source of dietary fiber. Previous work has suggested that dietary fibres may protect against the onset and continuation of a number of cardiovascular and gastrointestinal diseases. This article aims to examine what is currently understood about the fiber-like activities of alginate, particularly its effects on intestinal absorption and the colon, and therefore aims to gauge the potential use of alginate as a dietary supplement for the maintenance of normal health, or the alleviation of certain cardiovascular or gastrointestinal diseases.     

Whole grains — impact of consuming whole grains on physiological effects of dietary fiber and starch

Much of the present research on the physiological effects of dietary fiber and starch has been done on sources isolated from the parent material, and it is not clear whether they have the same effects if fed in the intact or whole grain. For dietary fiber, physiological effect depends on extent of fermentation in the large intestine, and this is influenced by chemical composition, solubility, physical form, and presence of lignin or other compounds. All of these factors are altered by isolation of a fiber source from the whole grain, and hence effects of eating fiber vary. Similarly, physical form and presence in the whole grain will affect digestibility of starch in the small intestine, which in turn influences the glycemic response and colonic effects determined by the extent of malabsorption and entry into the colon. Starch that enters the colon is fermented and produces short‐chain fatty acids, particularly butyrate, which is necessary to maintain a healthy mucosa. Hence, their presence within the whole grain may have important implications for health for both dietary fiber and starch. Evidence indicates that such effects are beneficial and that whole‐grain consumption should be encouraged.     

膳食纤维与结肠癌关系研究

结肠癌目前呈逐年上升趋势,而膳食纤维能降低患结肠癌风险性;近年随着研究不断深入,出现许多不同观点,有些观点甚至认为膳食纤维能增加患结肠癌风险性。该文介绍膳食纤维与结肠癌之间关系及可能性机理,并进行分析。     

Determination of Neutral Detergent Fiber in Breakfast Cereals: Pentose, Hemicellulose, Cellulose and Lignin Content

Cereals are often promoted as important sources of dietary fiber. Ninety one breakfast cereals available in Canada and four unprocessed wheat brans were therefore analyzed for neutral detergent fiber (NDF) after rapid digestion with α-amylase from porcine pancreas. Many breakfast cereals contained less than 5% NDF. Wheat cereals contained 5–30% NDF, oat cereals contained 5% NDF, and corn and rice contained little NDF. Cereal NDF was predominantly hemicellulose (pentosans); pentose sugars liberated under hydrolysis represented up to 15% of processed bran cereals and 20–25% of unprocessed bran.     

抗性淀粉的消化特性及其在食品中的应用

抗性淀粉(Resistant starch,RS)作为一种新型膳食纤维,不能被人体胃和小肠消化吸收,但可进入结肠中被肠道菌群发酵利用,进而发挥其降血糖、降血脂、预防心血管疾病和结肠癌等多种生理功效。这些特性使RS用于预防血脂异常和治疗胰岛素分泌相关的疾病,以及开发减肥食品,使通过饮食疗法来治疗2型糖尿病和冠心病成为可能。然而,在大多数天然食品中RS的含量甚微,难以达到控制血糖平衡的功效。因此,如何制备RS并将其应用到食品中已成为国内外食品行业的研究热点。作者综述了5类RS及其制备方法和消化特性,阐述了RS在谷物蒸煮、烘烤、油炸和功能性食品中的应用现状,并提出了RS的未来研究方向,以期为RS的深入研究及富含RS食品的开发提供参考。     

Dietary roles of non-starch polysachharides in human nutrition: a review

Nonstarch polysaccharides (NSPs) occur naturally in many foods. The physiochemical and biological properties of these compounds correspond to dietary fiber. Nonstarch polysaccharides show various physiological effects in the small and large intestine and therefore have important health implications for humans. The remarkable properties of dietary NSPs are water dispersibility, viscosity effect, bulk, and fermentibility into short chain fatty acids (SCFAs). These features may lead to diminished risk of serious diet related diseases which are major problems in Western countries and are emerging in developing countries with greater affluence. These conditions include coronary heart disease, colo-rectal cancer, inflammatory bowel disease, breast cancer, tumor formation, mineral related abnormalities, and disordered laxation. Insoluble NSPs (cellulose and hemicellulose) are effective laxatives whereas soluble NSPs (especially mixed-link β-glucans) lower plasma cholesterol levels and help to normalize blood glucose and insulin levels, making these kinds of polysaccharides a part of dietary plans to treat cardiovascular diseases and Type 2 diabetes. Moreover, a major proportion of dietary NSPs escapes the small intestine nearly intact, and is fermented into SCFAs by commensal microflora present in the colon and cecum and promotes normal laxation. Short chain fatty acids have a number of health promoting effects and are particularly effective in promoting large bowel function. Certain NSPs through their fermented products may promote the growth of specific beneficial colonic bacteria which offer a prebiotic effect. Various modes of action of NSPs as therapeutic agent have been proposed in the present review. In addition, NSPs based films and coatings for packaging and wrapping are of commercial interest because they are compatible with several types of food products. However, much of the physiological and nutritional impact of NSPs and the mechanism involved is not fully understood and even the recommendation on the dose of different dietary NSPs intake among different age groups needs to be studied.     

Nutritional factors and colon cancer

During the last 2 decades, substantial progress has been made in understanding the relationship between dietary constituents and the development of colon cancer in man. Unlike studies of cancer among smokers and nonsmokers, nutritional epidemiologic studies are confronted with the inherent difficulty of assessing reasonably precise exposures. The lack of consistency between international correlation studies and case‐control studies does not necessarily negate a dietary etiology of colon cancer because these inconsistencies may have arisen, at least in part, from methodological limitations. Some of these deficiencies in epidemiological studies of diet and cancer have been corrected; recent case‐control studies demonstrated that high dietary fat is a risk factor for colon cancer development and that an overall increase in intake of foods high in fiber might decrease the risk for colon cancer. The results of epidemiologic studies may be assumed to present conservative estimates of the true risk for cancer associated with diet. The populations with high incidences of colon cancer are characterized by high consumption of dietary fat, which may be a risk factor in the absence of factors that are protective, such as whole‐grain cereals and of other high fiber. Laboratory‐animal model studies have shown that certain dietary lipids and fibers influence tumorigenesis in the colon. The data of metabolic epidemiological and laboratory‐animal model studies are sufficiently convincing with respect to the enhancement of colon cancer by type of fat and protection by certain dietary fibers.