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。     

益生菌消化道耐受性的体外评价方法研究进展

一定数量的益生菌在机体肠道中可发挥有益的生理功效,但人体的消化道环境对微生物具有破坏甚至灭活作用,阻碍其益生特性的发挥,因此在益生菌的开发过程中需要采用体外模拟消化模型对其消化道耐受性进行评价。文章介绍了常用的体外模拟消化模型,重点对人体消化过程的生理参数以及现有体外消化模型的消化参数进行了综述,最后总结了体外模拟消化模型在益生菌研究中的具体应用,以期为益生菌消化道耐受性的标准化评价提供理论基础。     

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。     

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。     

胆盐理化性质及其对脂质消化的 影响机制研究进展

胆盐（BS）是胃肠道中的生物表面活性剂,在脂质消化过程中发挥着至关重要的作用。BS特殊的结构组成使之拥有不同于经典表面活性剂的理化性质,例如竞争性吸附和自组装形成胶束的行为,都参与了体内脂肪分解的过程。首先简要介绍了脂质在人体中消化吸收的过程和BS的基本性质,然后进一步阐述了BS影响脂质消化的作用机制,最后综述了近年来BS与肠道中蛋白质、脂质及其他外源食品组分相互作用的研究进展。探究BS在脂质消化中的角色,可以加深对脂质消化机制的理解,同时也可以通过调节脂质消化过程起到防治肥胖症等相关疾病的作用,还能基于BS的特殊性质开发新的载药系统。     

不同烹饪方式及体外模拟消化环境对鲟鱼蛋白质氧化及消化性的影响

研究水煮、汽蒸、微波、烤箱烤制、油炸5?种烹饪方式对鲟鱼肉的脂肪和蛋白质氧化的影响,熟肉在模拟消化过程中后续氧化情况及这些氧化反应与蛋白质消化性的相互关系。结果表明,不同烹饪方式均导致鱼肉的脂质与蛋白质氧化,其中烤制与油炸的样品氧化程度最显著,这些氧化反应会在模拟胃肠道消化过程中进一步加深,尤其在模拟肠消化阶段变化更为强烈。在烹饪与消化过程中,脂质与蛋白质的相互氧化作用也非常明显。此外,不同烹饪方式引起的蛋白质氧化显著影响蛋白质在模拟消化过程中的水解程度。在胃消化阶段,烤制与油炸样品中大分子蛋白氧化聚集形成致密结构,降低了蛋白质消化性;小肠消化后,由于部分小分子肽类（＜14?kDa）无法被彻底水解,各类熟制样品的游离氨基值均低于原料肉。?     

人工模拟胃肠道模型在食源性致病菌异质性研究中的应用进展

探究食源性致病菌在人体胃肠道环境中的异质性以及与肠道菌群间的相互作用对食源性致病菌的控制和预防具有十分重要的意义。人工模拟胃肠道模型基于人体胃肠道的生理过程,在体外条件下模拟体内的消化吸收情况,可以部分或完全替代活体实验,是研究食源性致病菌异质性以及致病机理的一种重要工具。本文系统综述应用人工模拟胃肠道模型研究食源性致病菌在胃肠道中的耐受、耐药异质性,为研究食源性致病菌在人体胃肠道中的异质性提供理论参考,同时将其与食源性致病菌动物感染模型（体内胃肠道模型）进行比较,综合评价人工模拟胃肠道模型在食源性致病菌异质性研究中的应用,以期为构建更加全面、科学的食品安全风险评估体系提供一定指导。     

膳食脂质消化行径及其影响机制研究进展

膳食脂质是肌体能量、必需营养物质和生物活性成分的重要来源或载体,其在体内的消化行径往往受到消化场所及存在形态差异的影响.本文通过对膳食脂质在胃肠道内不同阶段的消化行径进行综述,分析膳食脂质在各阶段消化过程中的变化,阐明了膳食脂质在机体代谢过程中与脂肪酶、胆盐的亲和机制,以及小肠内的微生物菌群与膳食脂质在消化吸收中的相互...     

体外消化模型评估食物过敏原致敏性研究进展

食物过敏受到了人们的广泛关注,检测和评价食物过敏原的潜在致敏性日益受到重视。体外胃肠道消化实验是食物过敏原潜在致敏性评价体系的重要环节之一。该文系统介绍体外胃肠道消化模型的种类及其应用,并综述体外消化模型与体内消化模型相比的优缺点,最后对食物过敏原消化稳定性与潜在致敏性的关系进行探讨,以期为食物过敏原潜在致敏性评价研究中体外模拟消化方法的应用及消化结果分析提供参考。     

海洋源活性物质乳液运载体系体外模拟消化吸收研究进展

海洋孕育着多种对人体健康有益的生物活性物质,如海洋生物活性肽、活性多糖、多不饱和脂肪酸等,这些物质因其自身较差的水溶性、胃肠道稳定性及易氧化等缺陷降低了自身生物利用率。乳液运载体系可输送海洋源生物活性物质,在一定程度上改善其应用缺陷,此外,体外消化吸收模拟系统可用于探究乳液输送海洋源活性物质消化过程中的消化特性、生物可及性及生物利用度。文章重点介绍了目前应用于海洋源活性物质乳液运载体系体外模拟消化模型,包括体外静态消化模型、动态消化模型及体外细胞培养消化吸收模拟模型,并分析比较各自的优缺点,同时对基于乳液递送海洋源生物活性物质体系的体外消化吸收模拟研究现状进行综述;最后,针对目前研究中存在的问题,对未来体外消化吸收模拟系统在海洋源活性物质乳液递送体系中的研究方向提出建议。     

Food lipid oxidation under gastrointestinal digestion conditions: A review

Abstract

Unravelling the relationship between food and health requires a more in-depth knowledge of the various changes occurring in the gastrointestinal tract during digestion and which may ultimately affect the nutritional quality and safety of ingested food lipids before absorption into the bloodstream. In this context, this review deals with the oxidation process of food lipids under digestive conditions and the studies carried out on this topic using different digestion models: in vitro, in vivo or ex vivo, static or dynamic, and including one, two and/or three digestive phases (oral, gastric and duodenal). These studies have contributed to clarifying the occurrence and extent of lipid degradation under such a particular environment, many of them also highlighting the factors affecting the advance or delay of the oxidation of dietary lipids during digestion, like: food lipid content, unsaturation degree and initial oxidative status; the presence in the food bolus of compounds showing antioxidant activity (polyphenols, tocopherols…) either added or naturally present; the presence in the food bolus of proteins (including iron or not); food technological or culinary processings (salting, smoking, cooking…), among others. Likewise, the methodologies employed to study lipid oxidation under digestive conditions are also summarized and future research perspectives are discussed.     

Can dynamic in vitro digestion systems mimic the physiological reality?

During the last decade, there has been a growing interest in understanding the fate of food during digestion in the gastrointestinal tract in order to strengthen the possible effects of food on human health. Ideally, food digestion should be studied in vivo on humans but this is not always ethically and financially possible. Therefore simple static in vitro digestion models mimicking the gastrointestinal tract have been proposed as alternatives to in vivo experiments but these models are quite basic and hardly recreate the complexity of the digestive tract. In contrast, dynamic models that allow pH regulation, flow of the food and injection in real time of digestive enzymes in the different compartments of the gastrointestinal tract are more promising to accurately mimic the digestive process. Most of the systems developed so far have been compared for their performances to in vivo data obtained on animals and/or humans. The objective of this article is to review the validation towards in vivo data of some of the dynamic digestion systems currently available in order to determine what aspects of food digestion they are able to mimic. Eight dynamic digestion systems are presented as well as their validation towards in vivo data. Advantages and limits of each simulator is discussed. This is the result of a cooperative international effort made by some of the scientists involved in Infogest, an international network on food digestion     

Identification of novel peptides with high stability against in vitro hydrolysis from bovine elastin hydrolysates and evaluation of their elastase inhibitory activity

Surviving in the gastrointestinal tract is crucial for biopeptides to exert physiological effects in vivo. To enrich elastase inhibitory peptides with high digestive stability, elastin peptides was separated by using ultrafiltration and macroporous resin column, then changes in elastase inhibitory activity, amino acid composition and peptide profile of elastin peptides during in vitro digestion were measured. The results revealed that the fraction F3 eluted by 40% ethanol displayed high digestive stability possibly due to the high content of Pro-containing peptides (20.25%). Particularly, thirty peptides in F3 exhibited high digestive stability and most of them contained GV and/or PG fragment. Since GV and PG could inhibit 35.70% and 51.77% elastase activity at the concentration of 20 mm , respectively, peptides in F3 survived in in vitro digestion which contained GV and PG sequence might be potential elastase inhibitors. This provides an approach for preparation of peptides with high bioactivity and digestive stability.     

Effect of in vitro gastrointestinal digestion on the antioxidant activity of protein hydrolysates prepared from Cape hake by‐products

The antioxidant activity of fish protein hydrolysates may change in the digestive tract during the human gastrointestinal digestion depending on their preparation conditions. Thus, the objective of this study was to assess the antioxidant properties of Cape hake hydrolysates prepared by three different methods (HPH‐A, HPH‐B and HPH‐C) and the effect of their in vitro gastrointestinal digestion on their antioxidant properties. HPH‐A showed the highest reducing power, while HPH‐B and HPH‐C exhibited the highest OH antiradical activity. Fe²⁺‐chelating activity was similar for all hydrolysates, but HPH‐C had a higher Cu²⁺‐chelating activity comparable to that of EDTA. The in vitro gastrointestinal digestion of hydrolysates caused a decrease in the DPPH inhibition, but an increase in scavenging ABTS in all hydrolysates. Copper‐ and iron‐chelating activities increased after digestion of hydrolysates. The results showed that the gastrointestinal digestion of HPHs generally increased their antioxidant properties.     

Dietary protein oxidation: A silent threat to human health?

Protein oxidation has become a topic of great scientific interest in the field of food science and nutrition. Food proteins are known to be preferential targets of radical species, and protein oxidation has relevant consequences on protein functionality and food quality. Current trends in this field call attention to the nutritional and health dimensions of oxidized foods. Both lipid and protein oxidation products are accumulated in food during processing and storage and also upon food intake during the subsequent digestion phases. The gastrointestinal tract and internal organs are exposed to the cytotoxic and mutagenic potential of these species. While the molecular basis of the pathogenesis of particular dietary lipid oxidation products is well known, the impact of dietary oxidized proteins on human health has been largely ignored. The well-established association between in vivo protein oxidation and aging and age-related diseases urges scientists to investigate the contribution of dietary protein oxidation to particular pathological conditions. Recent reports indicate the involvement of dietary protein oxidation species on particular health disorders, which emphasizes the link between dietary and in vivo protein oxidation.     

Laminarin in the dietary fibre concept

Dietary fibres consist of edible plant polysaccharides that are resistant to digestion and absorption in the human small intestine but undergo complete or partial fermentation in the colon. Seaweeds, notably Laminaria spp, are particularly rich in polysaccharides resistant to hydrolysis in the upper gastrointestinal tract and are, in consequence, considered as dietary fibres. Most of the carbohydrates from Laminaria spp are thought to be indigestible by humans. The main storage polysaccharide of these algae is laminarin, a β‐polymer of glucose. The aims of this work were, on the one hand, to compare various methods of extraction of laminarin by partial characterisation of the product obtained and, on the other hand, to study the fate of this polysaccharide and its effects in the gastrointestinal tract in order to determine its potential as a dietary fibre in human nutrition. Among four methods tested to extract laminarin, the best appeared to be a hot HCl‐based method. Human digestive enzymes did not hydrolyse laminarin, so this polysaccharide can be considered as a dietary fibre. After ingestion by rats, this polysaccharide was not found in faeces of these animals. It did not increase the intestinal transit and stool output in vivo, but it increased the contractile response of the stomach to acetylcholine in vitro. Copyright © 2004 Society of Chemical Industry     

Structural breakdown of starch-based foods during gastric digestion and its link to glycemic response: In vivo and in vitro considerations

The digestion of starch-based foods in the small intestine as well as factors affecting their digestibility have been previously investigated and reviewed in detail. Starch digestibility has been studied both in vivo and in vitro, with increasing interest in the use of in vitro models. Although previous in vivo studies have indicated the effect of mastication and gastric digestion on the digestibility of solid starch-based foods, the physical breakdown of starch-based foods prior to small intestinal digestion is often less considered. Moreover, gastric digestion has received little attention in the attempt to understand the digestion of solid starch-based foods in the digestive tract. In this review, the physical breakdown of starch-based foods in the mouth and stomach, the quantification of these breakdown processes, and their links to physiological outcomes, such as gastric emptying and glycemic response, are discussed. In addition, the physical breakdown aspects related to gastric digestion that need to be considered when developing in vitro–in vivo correlation in starch digestion studies are discussed. The discussion demonstrates that physical breakdown prior to small intestinal digestion, especially during gastric digestion, should not be neglected in understanding the digestion of solid starch-based foods.     

Effects of gallic acid and its alkyl esters on lipid oxidation during in vitro simulated gastrointestinal digestion of fresh and fried oysters

The process of lipid oxidation in fresh and fried oysters during in vitro digestion and the relationship between the antioxidant ability of phenolic esters with different chain lengths were investigated through co-digestion of fresh and fried oysters with gallic acid (GA) and its alkyl esters. Lipid oxidation in fresh and fried oysters during simulated digestion in vitro was observed according to increased conjugated diene value, conjugated triene value, thiobarbituric acid reactive substances and fluorescence intensity of aldehydes. Lipid oxidation in oysters was inhibited by GA and its alkyl esters during in vitro digestion effectively. As the alkyl chain length increased, the antioxidant effect first increased and then decreased, and butyl gallate achieved the highest effect among the GA and its alkyl esters we studied, which suggests that the antioxidant efficiency of GA and its alkyl esters in the digestive system may follow the ‘cut-off’ effect.     

The Role of Dietary Phenolic Compounds in Protein Digestion and Processing Technologies to Improve Their Antinutritive Properties

Digestion is the key step for delivering nutrients and bioactive substances to the body. The way different food components interact with each other and with digestive enzymes can modify the digestion process and affect human health. Understanding how food components interact during digestion is essential for the rational design of functional food products. Plant polyphenols have gained much attention for the bioactive roles they play in the human body. However, their strong beneficial effects on human health have also been associated with a negative impact on the digestion process. Due to the generally low absorption of phenolic compounds after food intake, most of the consumed polyphenols remain in the gastrointestinal tract, where they then can exert inhibitory effects on enzymes involved in the degradation of saccharides, lipids, and proteins. While the inhibitory effects of phenolics on the digestion of energy‐rich food components (saccharides and lipids) may be regarded as beneficial, primarily in weight‐control diets, their inhibitory effects on the digestion of proteins are not desirable for the reason of reduced utilization of amino acids. The effect of polyphenols on protein digestion is reviewed in this article, with an emphasis on food processing methods to improve the antinutritive properties of polyphenols.     

Survival of Lactobacillus rhamnosus strains inoculated in cheese matrix during simulated human digestion

Survival of probiotic bacteria during transit through the gastrointestinal (GI) tract is influenced by a number of environmental variables including stomach acidity, bile salts, digestive enzymes and food matrix. This study assessed survival of seven selected Lactobacillus rhamnosus strains delivered within a model cheese system to the human upper GI tract using a dynamic gastric model (DGM). Good survival rates for all tested strains were recorded during both simulated gastric and duodenal digestion. Strains H12, H25 and N24 demonstrated higher survival capacities during gastric digestion than L. rhamnosus GG strain used as control, with H12 and N24 continuing to grow during duodenal digestion. Strains L. rhamnosus F17, N24 and R61 showed adhesion properties to both HT-29 and Caco-2 cells. The ability to attach to the cheese matrix during digestion was confirmed by scanning electron microscopy, also indicating production of extracellular polysaccharides as a response to acid stress.