Using a dynamic artificial digestive system to investigate heme iron nitrosylation during gastro-intestinal transit

Chemical effects of nitrite reduction during digestion of cured cooked and recooked meat on nitrosation, nitrosylation and oxidation

Nitrites are food additives used in meatfor their bacteriological, technological and sensory properties.However, they are suspected to be involved in the formation of various mutagenic nitroso compounds (NOCs).With a view to reducing the use of nitrite in meat products to improve the healthiness thereof, the formation of NOCs was studied during dynamic in vitro digestion ofcooked and recooked meats preparedwith various levels of nitrite. Residual nitrite and nitrate and NOCs were evaluated in the gastric and ileal compartments.In the absence of added nitrite, basalnitrosation and nitrosylation were detected, probably due to the oxidation of ammonium salts present in the gastric fluid. Nitrosamines, nitrosyl heme and nitrosothiols displayed different kinetics of formation and degradation,reflecting a possible transfer of nitric oxide from one substrate to another. A protective effect of nitrite on lipid oxidation was also observed during digestion.

Utilizing the influence of protein enrichment of meal components as a strategy to possibly prevent undernutrition in the elderly: an in vitro approach

Nutritional strategies are required to limit the prevalence of denutrition in the elderly. With this in mind, fortified meals can provide more protein, but their digestibility must be ensured. Using a dynamic in vitro digester, DIDGI®, programmed with the digestion conditions of the elderly, we evaluated the supplementation of each component of a meal and assessed protein digestibility, amino acid profile, micro-nutrients and vitamins bioaccessibility for a full course meal. Higher protein digestibility was evidenced for the fortified meal, with higher release of essential amino acids. Moreover the large increase of leucine released was comparable to the range advocated for the elderly to favour protein anabolism. This in vitro study underlines the interest of using dish formulations to meet the nutritional needs of seniors, which is why this work will be completed by a clinical study in nursing home.

Effects of Marine Bioactive Compounds on Gut Ecology Based on In Vitro Digestion and Colonic Fermentation Models

Digestion and the absorption of food compounds are necessary steps before nutrients can exert a role in human health. The absorption and utilization of nutrients in the diet is an extremely complex dynamic process. Accurately grasping the digestion and absorption mechanisms of different nutrients or bioactive compounds can provide a better understanding regarding the relationship between health and nutrition. Several in vitro models for simulating human gastrointestinal digestion and colonic fermentation have been established to obtain more accurate data for further understanding of the metabolism of dietary components. Marine media is rich in a wide variety of nutrients that are essential for humans and is gaining increased attention as a research topic. This review summarizes some of the most explored in vitro digestion and colonic fermentation models. It also summarizes the research progress on the digestion and absorption of nutrients and bioactive compounds from marine substrates when subjected to these in vitro models. Additionally, an overview of the changes imparted by the digestion process on these bioactive compounds is provided, in order to support those marine resources that can be utilized for developing new healthy foods.

The study of the intensification of technological parameters of the sausage production process

One of the sources of sodium are meat products. Increased consumption of meat products and sodium intake leads to serious health problems. The task of reducing the dosage of sodium chloride in minced meat needs to be addressed. The partial replacement of table salt with sea salt will reduce the sodium concentration in products to 20%. It is established that this modification increases the moisture-binding properties of minced meat and lowers the dosage of salt in the mass of raw meat, which will reduce the level of harm to the body due to excessive consumption of sausages. It is proposed to introduce a bacterial preparation based on the strain Staphylococcus carnosus, which will reduce the amount of sodium nitrite in the finished products. Technology has been developed to regulate the composition of microelements in meat products by enriching them with a kelp extract. It was found that changes in the composition of minced meat can adversely affect the taste and physicochemical properties of the product, which is confirmed by expert studies. As a result of laboratory studies, it was found that a partial change of salt in the sea helps to improve the stability and physicochemical quality of minced meat (active acidity, water activity, moisture retention, and shear stress). According to the research results, the recipe of sausages recommended for implementation at the enterprises of the meat processing industry of Ukraine has been developed.

Investigation of Escherichia coli O157:H7 Survival and Interaction with Meal Components during Gastrointestinal Digestion

Escherichia coli O157:H7 is responsible for foodborne poisoning, incriminating contaminated animal food and especially beef meat. This species can survive in the digestive tract, but, up to now, very few studies have considered its survival during the gastrointestinal digestion of meat. The present study aimed to investigate the survival of the pathogenic strain E. coli O157:H7 CM454 during the gastrointestinal digestion of ground beef meat and its interactions with meal components using a semidynamic digestive model. The CM454 strain in meat survived throughout digestion despite acidic pH (pH 2) and the presence of bile salts. The addition of nitrite and ascorbate in the digestion medium led to a decrease in strain survival. During digestion, a release of free iron was observed, which was accentuated in the presence of the CM454 strain. In addition, the strain modified the Fe²⁺/Fe³⁺ ratio, in favor of Fe²⁺ compared to the noninoculated meat sample. In the presence of nitrite, nitroso compounds such as nitrosamines, nitrosothiols, and nitrosylheme were formed. E. coli O157:H7 CM454 had no impact on N-nitrosation but seemed to decrease S-nitrosation and nitrosylation.

A review on the food digestion in the digestive tract and the used in vitro models

It is crucial to replicate or mimic the human digestive system conditions closely in model systems to have the food digestion-related data as accurate as possible. Thus, the data obtained could contribute to studies like those on the relationship between health and nutrition. This review aims to express the human digestion system's role in food digestion and compare the capability of the models used in simulations, especially the dynamic in vitro models. Activities of the human digestive system governing food digestion and the food matrix's disintegration mechanism in the digestive system were discussed. Dynamic in vitro models and their relevance to the human digestive system were described. Advancements in the last 20 years, as well as limitations of those artificial systems, with prospects, were discussed. Extensive use and improvement on these models will extend our knowledge of the food matrix and digestive system's complex interaction. Thus, it will be possible to design next-generation foods with improved health benefits.

Iron supplementation and iron-fortified foods: a review

About one-third of the world population is suffering from iron deficiency. Delivery of iron through diet is a practical, economical, and sustainable approach. Clinical studies have shown that the consumption of iron-fortified foods is one of the most effective methods for the prevention of iron deficiency. However, supplementing iron through diet can cause undesirable side-effects. Thus, it is essential to develop new iron-rich ingredients, iron-fortified products with high bioavailability, better stability, and lower cost. It is also essential to develop newer processing technologies for more effective fortification. This review compared the iron supplementation strategies used to treat the highly iron-deficient population and the general public. We also reviewed the efficacy of functional (iron-rich) ingredients that can be incorporated into food materials to produce iron-fortified foods. The most commonly available foods, such as cereals, bakery products, dairy products, beverages, and condiments are still the best vehicles for iron fortification and delivery.Scope of reviewThe manuscript aims at providing a comprehensive review of the latest publications that cover three aspects: administration routes for iron supplementation, iron-rich ingredients used for iron supplementation, and iron-fortified foods.

Hemin Prevents Increased Glycolysis in Macrophages upon Activation: Protection by Microbiota-Derived Metabolites of Polyphenols

Meat consumption plays a critical role in the development of several types of cancer. Hemin, a metabolite of myoglobin produced after meat intake, has been demonstrated to be involved in the cancer initiation phase. Macrophages are key components of the innate immunity, which, upon activation, can prevent cancer development by eliminating neoplastic cells. Metabolic reprogramming, characterized by high glycolysis and low oxidative phosphorylation, is critical for macrophage activation. 3,4-dihydroxyphenylacetic acid (3,4DHPAA) and 4-hydroxyphenylacetic acid (4HPAA), both microbiota-derived metabolites of flavonoids, have not been extensively studied although they exert antioxidant properties. The aim of this study was to determine the effect of hemin on the anticancer properties of macrophages and the role of 3,4DHPAA and 4HPAA in metabolic reprogramming and activation of macrophages leading to the elimination of cancer cells. The results showed that hemin inhibited glycolysis, glycolytic, and pentose phosphate pathway (PPP) enzyme activities and hypoxia-inducible factor-1 alpha (HIF-1α) stabilization, which interferes with macrophage activation (evidenced by decreased interferon-γ-inducible protein 10 (IP-10) release) and their ability to eliminate cancer cells (via cytotoxic mediators and phagocytosis). Hemin also reduced the mitochondrial membrane potential (MMP) and mitochondrial mass in macrophages. 3,4DHPAA and 4HPAA, by stimulating glycolysis and PPP, prevented the impairment of the macrophage anticancer activity induced by hemin. In conclusion, 3,4HPAA and 4HPAA administration could represent a promising strategy for preventing the reduction of macrophage activation induced by hemin.

Electrostatically Fabricated Three-Dimensional Magnetite and MXene Hierarchical Architecture for Advanced Lithium-Ion Capacitors

Conversion-type magnetite shrewdly shows abundance, nontoxicity, and high lithium storage capacity. However, either pristine magnetite or nanocomposites with two-dimensional materials cannot prevent restacking, pulverization, and poor structural homogeneity simultaneously because of a lack of universal interfacial interactions. Here, an electrostatic self-assembly strategy is uncovered between hollow Fe₃O₄/C microspheres (with H⁺-induced quasi-intrinsic positive charge) and few-layer MXenes (with intrinsic negative charge from terminating functionalities). This strategy realizes the uniform and interconnected architecture of Fe₃O₄/C@MXene that favors fast Li⁺ diffusion, easy electron/charge transfer, and suppressed pulverization. Specifically, after the long-term cycling, an undegraded specific capacity of 907 mA h g^-1 remains at 0.5 A g^-1. Further adoption of such superior anode in 4.0 V lithium-ion capacitors results in a high energy density of 130 W h kg^-1, a maximum power density of 25,000 W kg^-1, and excellent cycling stability. This work thus sheds light on a generic self-assembly process where intrinsic electrostatic interaction plays an essential role.