基于肠道吸收机制的膳食多酚代谢研究进展

膳食多酚是植物性食物的重要成分,不仅与食品的风味和颜色等品质直接相关,还有利于人体健康。由于它们在基质释放、消化、吸收、代谢和组织分布期间发生改变,使得各种酚类化合物生物利用度有一定的差异。饮食中含量最丰富的不一定具有最佳生物利用度,多酚的吸收转化及生物利用度是多酚生物活性主要研究热点之一。本文以多酚肠道吸收机制为基点,综述了膳食多酚在胃肠道释放、吸收、代谢等过程,以期为多酚类保健食品的研发提供依据。     

膳食成分对儿茶素生物利用率的影响及多酚协同增效的研究进展

儿茶素是一种酚类化合物,具有抗过敏、抗氧化、抗炎和抗菌等多种功效,对人体健康有诸多益处。但由于儿茶素热稳定性差、生物利用率较低,膳食摄入的碳水化合物、蛋白质、脂质等物质易与儿茶素在胃肠道中发生相互作用,影响儿茶素的吸收、分布、代谢和排泄过程,进而影响其生物利用率和生理活性。此外,当两种或多种天然多酚类化合物联合应用时可能会产生协同增效作用,可以抑制食品生产加工污染物、降脂减肥、降血糖、抗炎抗菌等。因此,本文主要对膳食成分对儿茶素生物利用率的影响进行综述,阐明了儿茶素和膳食多酚相互作用的机制和两者在协同增效方面的应用前景。     

大米、小麦和玉米哪种营养价值最高?

正首先,我们来确认一下营养的含义,食物所含的养分,生物从外界摄取养料滋补身体以维持其生命。营养学家对营养所作的解释是:食物中的营养素和其他物质间的相互作用与平衡对健康和疾病的关系,以及机体摄食、消化、吸收、转运、利用物质的过程。就单以营养素的种类及比例来做出比较:大米:1、淀粉:大米中含淀粉62%~86%,蛋白质含量为6%~9%之间,脂类含量约0.6%~3.9%,水分含量基本在13%~16%之     

动态智能人体消化模拟体系及其在食品研究领域中的应用

人体消化模拟体系是对人体胃肠道的消化环境进行体外模拟的模型,主要作用是预测对人体有保护或危害作用的利害成分的生物可及性,真实反映食物中的利害成分在体内的释放、吸收情况。由于人体消化模拟体系的应用能够提高研究效率,节约科研成本,同时能够使食品的开发更符合人体需求,因此对人体消化模拟体系的开发越来越被关注。随着研究的深入,简单的静态人体消化模拟体系已经不能满足需求,为此越来越多的动态智能消化体系不断被研制并且广泛应用。本文将系统介绍国内外人体消化模拟体系的发展现状及其在营养及功能成分生物利用、食品的营养配方、食品药品安全性评价、食品污染物风险评估等研究中的应用情况,一方面能为开发与我国饮食结构相适应的高仿真的动态、多维、智能的体外模拟消化体系提供借鉴,另一方面,为经济、有效地开发符合我国人民健康需求的营养安全的食品寻求一条便捷之路。     

体外模拟消化在水产品营养活性物质研究中的应用进展

食物营养素对人体健康的影响主要取决于胃肠道内的消化过程。体外模拟消化可以综合模拟人体消化过程,具有重现性好、简单灵活、应用广泛等优点,不仅可以预测食物成分、结构和消化特性之间的关系,还可以评估食物成分的生物利用度和消化代谢物对人体健康的影响,是研究食品中营养物质的有效工具。体外模拟消化已经广泛用于水产品营养活性成分的研究,本文综述了体外模拟消化模型的现状,对静态模型和动态模型的优缺点及其应用进行了详细描述,并系统总结了体外模拟消化在研究水产品蛋白质消化率、生物活性肽消化稳定性、多糖消化酵解特性及脂质氧化稳定性等方面的应用。此外,还对体外模拟消化模型的局限和优化提出了建议,以期对其在海洋生物医药、海洋功能食品等领域的应用有所助益。     

胃肠道消化过程中脂质氧化的影响因素、健康危害及控制研究进展

研究证实,油脂和富含脂质的食品极易在胃肠道消化过程中发生氧化反应,产生的丙二醛、4-羟基-2-己烯醛(4-HHE)等氧化产物能够对机体造成健康危害。本文对胃肠道消化过程中脂质氧化反应的影响因素、健康危害及植物多酚、类黑精等食品组分干预作用等方面的研究进展进行综述,以期为通过改善膳食结构等途径减少胃肠道消化过程中脂质氧化反应造成的健康危害提供参考。     

体外消化过程中影响类胡萝卜素生物利用率的因素

类胡萝卜素是存在于很多水果蔬菜中的天然色素,具有VA原活性、抗氧化等特性,在维持人体健康方面发挥重要作用。从食物基质中释放的脂溶性类胡萝卜素包裹在脂滴中被运送到小肠,与胆盐、脂类等形成水溶性胶束,随后被小肠上皮细胞吸收并进一步代谢。在体外消化实验中,影响类胡萝卜素生物利用率的因素很多,类胡萝卜素种类及结构、食物基质、脂类、样品加工处理方法、消化模型、细胞模型、检测方法及指标等的不同都会造成最终的生物利用率评估值的不同,另外不同因素对生物利用率的影响因类胡萝卜素种类而异,且各因素间可能存在协同效应。     

体外人胃肠模拟系统在食物消化行为研究中的应用进展

人体胃肠道在食物消化和营养物质的吸收过程中具有非常重要且关键的作用,在对人体胃肠道功能进行研究过程中常存在伦理问题,而体外人胃肠模拟系统可有效解决该问题,对促进胃肠道功能的研究和食物消化行为的研究也起着非常重要的作用。该文对体外人胃肠模拟系统的研究现状、研究局限性等进行了综述,并对体外人胃肠模拟系统的应用研究进行展望,提出一些发展建议和意见,以期促进体外人胃肠模拟系统在食物消化行为研究方面的工作。     

营养的心理表象与心理误区(上)

一、关于营养 营养和营养学一直被界定为单纯的自然科学。关于营养,权威的说法是:机体摄取、消化、吸收和利用食物或养料的整个过程的统称。亦用以表示食物中营养素含量的多少和质量好坏。     

类胡萝卜素肠道吸收及生物利用度研究进展

类胡萝卜素是一种广泛存在于果蔬中的脂溶性色素,在预防疾病和保护人体健康方面发挥重要功能,但是人体无法合成类胡萝卜素,只能从食物中摄取,且由于类胡萝卜素的溶解性差、不稳定等原因,其生物利用度通常非常低。本文简述类胡萝卜素的消化过程,以SR-B1、CD36、NPC1L1等肠道转运蛋白为重点,介绍类胡萝卜素在小肠上皮细胞的吸收,并从类胡萝卜素的亲脂性与化学存在形式、食物基质、胃肠道消化、宿主因素及肠道转运蛋白的表达或活性等方面出发,综述影响类胡萝卜素生物利用度的因素。     

An integrated look at the effect of structure on nutrient bioavailability in plant foods

The true bioavailability of a nutrient being intrinsically coupled to the specific food matrix in which it occurs remains poorly considered in nutrition science. During digestion, the food matrix and, in particular, the structure of food modulate the extent and kinetics to which nutrients and bioactive compounds make themselves available for absorption. In this perspective, we describe an integrated look at the effect of structure on nutrient bioavailability in plant foods. Based on this integrated look, cell wall integrity and the particle size of the plant material during its transit in the small intestine determine the bioavailability of plant nutrients; in turn, cell wall integrity and particle size are determined by the level of oral processing and, accordingly, what subsequently escapes digestion in the upper intestine and is utilized by colon microbiota. Ultimately, the effect on nutrient digestion is linked to food structure through each step of digestion. A consideration of the structure rather than just the composition of foods opens up possibilities for the design of healthier foods. © 2018 Society of Chemical Industry     

黄芩苷降脂机制及其生物利用度改善方法的研究进展

黄芩苷属于黄酮类化合物,具有降血糖、抗炎和降脂等多种生物活性,尤其是其降脂活性在近些年来受到了广泛关注。然而,由于独特的胃肠吸收特征,黄芩苷的生物利用度较低,使得其需要较高的剂量才能达到良好的降脂效果,从而限制其应用。因此,利用各种物理或化学的方法改善黄芩苷的生物利用度已成为国内外的研究热点。该研究从抑制脂肪生成、促进脂质代谢、抑制食欲、调节营养吸收和肠道菌群等方面总结了黄芩苷的降脂活性及其作用机制,并从胃肠吸收与代谢方面分析了黄芩苷生物利用度差的原因,进一步综述了目前改善黄芩苷生物利用度的方法。最后,对提高黄芩苷生物利用度的研究进行了展望,为推动黄芩苷在食品、营养和保健品领域中的高值化应用提供了理论依据。     

食品体系组成及加工方式对植物次生代谢物生物利用度的影响研究进展

食用富含植物次生代谢物的食物能够调控人体健康,然而由于溶解性差、化学不稳定等因素,这些次生代谢物的生物利用度通常较低.食品加工导致的食品组成破坏是植物次生代谢物释放的重要条件,同时食品体系组成还会影响植物次生代谢物的吸收.本文综述了脂质和蛋白质等不同食品体系组成以及热处理、机械加工、发酵等食品加工方式对植物次生代谢物生...     

Bioavailability of Micronutrients from Plant Foods: An Update

Deficiencies of iron, zinc, iodine and vitamin A are widespread in the developing countries, poor bioavailability of these micronutrients from plant-based foods being the major reason for their wide prevalence. Diets predominantly vegetarian are composed of components that enhance as well as inhibit mineral bioavailability, the latter being predominant. However, prudent cooking practices and use of ideal combinations of food components can significantly improve micronutrient bioavailability. Household processing such as heat treatment, sprouting, fermentation and malting have been evidenced to enhance the bioavailability of iron and β-carotene from plant foods. Food acidulants amchur and lime are also shown to enhance the bioavailability of not only iron and zinc, but also of β-carotene. Recently indentified newer enhancers of micronutrient bioaccessibility include sulphur compound-rich Allium spices—onion and garlic, which also possess antioxidant properties, β-carotene-rich vegetables—carrot and amaranth, and pungent spices—pepper (both red and black) as well as ginger. Information on the beneficial effect of these dietary compounds on micronutrient bioaccessibility is novel. These food components evidenced to improve the bioavailability of micronutrients are common ingredients of Indian culinary, and probably of other tropical countries. Fruits such as mango and papaya, when consumed in combination with milk, provide significantly higher amounts of bioavailable β-carotene. Awareness of the beneficial influence of these common dietary ingredients on the bioavailability of micronutrients would help in devising dietary strategies to improve the bioavailability of these vital nutrients.     

食品基质及加工方式对多酚生物利用度影响的研究进展

酚类化合物是植物性食品中的重要成分,具有多种功能活性,但因其生物利用度低,不能在体内完全发挥其生物活性。因此寻找到一条有效的途径来提高其生物利用率非常必要。本文综述了多糖、蛋白质、脂质三种食品基质及不同加工方式对多酚生物利用度的影响,以期为食品加工中提高多酚生物利用度提供借鉴和思考。     

改善番茄红素生物利用度的研究进展

番茄红素的生物利用度是决定其营养价值的关键因素,天然存在的番茄红素生物利用度较低。番茄红素的异构化、食品分散体系以及食品组分与番茄红素之间的相互作用对番茄红素的生物利用度有着重要影响。近年来,食品加工、赋形剂乳液和构建共消化体系等方法越来越多地应用于改善番茄红素生物利用度中,相关的研究也成为热点。本文从番茄红素的吸收机制、影响番茄红素生物利用度的因素、改善番茄红素吸收的方法和番茄红素生物利用度的评价方法等方面进行综述,并对番茄红素生物利用度研究趋势和前景进行展望。     

Cancer cell antiproliferation activity and metabolism of black carrot anthocyanins

The antiproliferation activity of a black carrot anthocyanin-rich extract (BC-ARE) on human cancer cells (HT-29 colorectal adenocarcinoma and HL-60 promyelocytic leukaemia) and metabolism of its characteristic anthocyanins (acylated and nonacylated forms) in humans were investigated. Cancer cells were exposed for 24 h to 0.0–2.0 mg/mL of BC-ARE. Anthocyanin-rich extract inhibited proliferation of both types of cancer cells in a dose-dependent manner. After ingestion of a black carrot concentrate, three acylated and two nonacylated anthocyanins were excreted in the volunteers (n = 4) urine (0.048% of the administered dose). The anthocyanins were characterized by HPLC-DAD-ESI-MS/MS. Urine recovery of nonacylated anthocyanins was 8-fold higher than that of acylated anthocyanins.Industrial relevanceNatural pigments have achieved commercial significance as food colorants due to the fact that consumers perceive them as safe additives. At present extracts rich in acylated anthocyanins, which are known for their outstanding stability, serve as a major source of natural food colours for the food colorant industry with purple sweetpotato, red cabbage and black carrot being the major sources. Beside aesthetic values, anthocyanins possess enhanced physiological activity due to their potent antioxidant properties and enhance the health-promoting qualities of foods. Our findings on cancer cell antiproliferation activity of an anthocyanin-rich black carrot extract as well as information about the bioavailability of black carrot anthocyanins could lead to an increased application of these natural food colorants by the food industry.     

Toxicity of ingested cadmium to the nematode Caenorhabditis elegans

Benthic organisms ingest dissolved and particle-bound contaminants together with their food, whereas it is not clear which fraction of the ingested suspension causes the toxic effects. In the standard toxicity test using the nematode Caenorhabditis elegans, the organisms are fed with bacteria that bind contaminants, thus influencing the bioavailability of the contaminants for the organisms. To unravel the role of food bacteria in the toxicity of contaminants in C. elegans, suspensions with varying densities of bacteria were spiked with the toxic metal cadmium (Cd), either via the water or via the bacteria. The toxicity of Cd to C. elegans was clearly related to the uptake of bacteria in the nematode's gut. An increase in the bacterial density resulted in a significant decrease in the toxicity of Cd such that toxic effects better correlated with the aqueous than with the bacterial-bound or total Cd concentrations. The results suggested that the aqueous Cd that was ingested together with the food was the best available fraction and thereby mainly caused the observed toxicity on the reproduction of C. elegans.     

Evaluating Global Barriers to the Use of Red Palm Oil as an Intervention Food to Prevent Vitamin A Deficiency

Abstract: Vitamin A deficiency (VAD) is an important cause of blindness and premature death. Red palm oil (RPO) is the richest food source of VA‐forming carotenoids. RPO carotenoid concentration and bioavailability were evaluated and this data used to estimate the amount of RPO needed to meet VA requirements. Amounts ranged from 6.7 to 29.2 g/d (1.5 to 6.5 tsp/d), which are easily consumed. The amount of RPO needed to supply recommended dietary intakes of VA for all 208100000 individuals most in danger for VAD worldwide for 1 y is 0.80 million metric tons, a fraction of annual world palm oil production. Despite its abundance, RPO has seldom been used for VAD prevention on a national level. Pareto charts were constructed to highlight the variables that influence the ability of RPO to prevent VAD on the national level. The most important variable by far was refining method. Most refining methods are designed to remove color and flavor from RPO, resulting in a bland product that lacks carotenoids. Thus, the important barriers to the use of RPO as a food‐based intervention to prevent VAD appear to be that: (1) RPO requires refining, limiting its profitability and availability for small farmers. (2) The goal of most refining methods is to create a low‐cost bland, odorless, and colorless fat which requires removal of carotenoids. (3) Cost, since RPO use competes with high‐dose VA supplements, which are heavily subsidized. It appears that RPO could prevent VAD in many food‐deficit countries if carotenoids were conserved during oil refining, and costs were low enough to make it an attractive alternative to nutritional supplements.     

A Review on the Relationship Between Food Structure,Processing, and Bioavailability

This review highlights the effects of processing and food matrix on bioaccessibility and bioavailability of functional components. Human digestive system is reviewed as an element in bioavailability. Methods for bioaccessibility and bioavailability determination are described. Information about the location of functional compounds in the tissue is presented to portray the matrix information. Research data on the effects of food matrix and processing on bioaccessibility and bioavailability are summarized. Finally, trends in the development of functional component delivery systems are included.