Publications by authors named "Thierry Sayd"

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.

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Wheat proteins can trigger immunogenic reactions due to their resistance to digestion and immunostimulatory epitopes. Here, we investigated the peptidomic map of partially digested bread samples and the fingerprint of epitope diversity from 16 wheat genotypes grown in two environmental conditions. Flour protein content and composition were characterized; gastric and jejunal peptides were quantified using LC-MS/MS, and genotypes were classified into high or low bread protein digestibility.

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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 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.

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The influence of partial replacement of animal protein by plant-based ingredients on the protein digestibility of beef burgers was investigated. Beef burgers were supplemented with fava bean protein concentrate (FB) or a mixture of FB and flaxseed flour (FBFS), both processed by extrusion, at different levels: 0 (control), 10, 15, and 20 % (w/w). A pilot sensory analysis was conducted to select the percentage of flour inclusion for further assays: control, 10 % FB, and 10 % FBFS.

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Mass spectrometry has become the technique of choice for the assessment of a high variety of molecules in complex food matrices. It is best suited for monitoring the evolution of digestive processes in vivo and in vitro. However, considering the variety of equipment available in different laboratories and the diversity of sample preparation methods, instrumental settings for data acquisition, statistical evaluations, and interpretations of results, it is difficult to predict a priori the ideal parameters for optimal results.

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digestions of dry-cured sausages formulated with four different rates of added sodium nitrite and sodium nitrate (NaNO / NaNO, in ppm: 0/0; 80/80; 120/120; 0/200) were performed with a dynamic gastrointestinal digester (DIDGI®). The chemical reactivity of the potentially toxic nitroso-compounds (NOCs), oxidation reactions products and different iron types were evaluated over time. No nitrite nor nitrate dose effect was observed on NOCs' chemical reactivity.

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The protein degradation of alfalfa hay after tannin supplementation was monitored during wethers digestion. Three rumen-cannulated wethers were infused a tannin solution, and water for control, through the cannula. The digestion time-points samples were collected in the rumen and in the abomasum, and the small intestine compartments.

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The aim of this study was to characterize the effects of tannins on plant protein during sheep digestion using a digestomic approach combining (rumen) conditions and an digestive system (abomasum and small intestine). Ruminal fluid from wethers infused with a tannin solution or water (control) was introduced into the digester, and protein degradation was followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Tannin infusion in the rumen led to a clear decrease in protein degradation-related fermentation end-products, whereas ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo) protein was more abundant than in control wethers.

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The marketing of poultry livers is only authorized as fresh, frozen, or deep-frozen. The higher consumer demand for these products for a short period of time may lead to the marketing of frozen-thawed poultry livers: this constitutes fraud. The aim of this study was to design a method for distinguishing frozen-thawed livers from fresh livers.

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Food processing affects the structure and chemical state of proteins. In particular, protein oxidation occurs and may impair protein properties. These chemical reactions initiated during processing can develop during digestion.

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Purpose: Objective markers of usual diet are of interest as alternative or validating tools in nutritional epidemiology research. The main purpose of the work was to assess whether saliva protein composition can reflect dietary habits in older adults, and how type 2 diabetes impacted on the saliva-diet correlates.

Methods: 214 participants were selected from 2 European cohorts of community-dwelling older adults (3C-Bordeaux and Seniors-ENRICA-2), using a case-control design nested in each cohort.

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The objective of the study is to develop a workflow to screen protein extracts and identify their nutritional potential as high quality nutritional culinary aids for recipes for the elderly. Twenty-seven protein extracts of animal, vegetable, and dairy origin were characterized. We studied their fate by monitoring static in vitro digestion, mimicking the physiological digestion conditions of the elderly.

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Food-derived bioactive peptides have generated an increasing interest in the field of health and well-being research. They can act either against the metabolic syndrome, participate in regulating the oxidation balance or act on the immune system. The aim of this study is to develop a workflow to generate bioactive peptides from three porcine offals namely, heart, liver, and lung and one muscle the Longissimus Dorsi, by combining in silico and in vitro approaches.

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The International Agency for Research on Cancer recently classified cured meats as carcinogenic for humans and red meats as probably carcinogenic. Mutagens can be formed during meat process or digestion. In a previous study, we used a dynamic artificial digestive system (DIDGI®) to investigate protein oxidation and N-nitrosation during bovine meat digestion.

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Obesity induced by overfeeding ultimately can lead to nonalcoholic fatty liver disease, whereas dietary fiber consumption is known to have a beneficial effect. We aimed to determine if a supplementation of a mix of fibers (inulin, resistant starch and pectin) could limit or alleviate overfeeding-induced metabolic perturbations. Twenty female minipigs were fed with a control diet (C) or an enriched fat/sucrose diet supplemented (O + F) or not (O) with fibers.

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Nitrosation can occur during meat digestion due to the physicochemical conditions of the stomach (low pH and reducing conditions). The aim of the present study was to elucidate the link between the nitrosation of proteins from beef meat and their digestibility by comparing cooked meat digested with and without the addition of nitrite. To do this, a dynamic in vitro artificial digestive computer-controlled system (DIDGI®) was used to reflect human gastro-intestinal conditions.

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PSE-like technological defect in the meat industry is of great importance due, to the economic loss it can cause. It has been studied from the biochemical perspective but very few studies have focused on tissular characterization. This study proposes innovative approaches that combine mechanistic elucidation and the discovery of potential biomarkers.

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Red meat is probably carcinogenic to humans (WHO/IARC class 2A), in part through heme iron-induced lipoperoxidation. Here, we investigated whether red meat promotes carcinogenesis in rodents and modulates associated biomarkers in volunteers, speculating that an antioxidant marinade could suppress these effects via limitation of the heme induced lipid peroxidation. We gave marinated or non-marinated beef with various degrees of cooking to azoxymethane-initiated rats, mice, and human volunteers (crossover study).

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The chemical changes (oxidation/nitrosation) of meat proteins during digestion lead to a decrease in their nutritional value. Moreover, oxidized and nitrosated amino acids are suspected to promote various human pathologies. To investigate the mechanisms and the kinetics of these endogenous protein modifications, we used a dynamic artificial digestive system (DIDGI®) that mimics the physicochemical conditions of digestion.

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Natural collagen is easily available from animal tissues such as bones. Main limitations reported in the use of natural collagen are heterogeneity and loss of integrity during recovery. However, its natural complexity, functionality and bioactivity still remain to be achieved through synthetic and recombinant ways.

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This paper deals with the extraction and emulsifying properties of proteins from Chlorella vulgaris. Solubilisation of proteins has been achieved using high pressure cell disrupter under pH=7 or pH=12. The higher solubilisation yield (52±3%w/w) was obtained using a combination of alkaline conditions and mechanical treatments (2.

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Background & Aims: Postprandial lipemia has been associated with inflammation, oxidative stress and vascular dysfunction. This metabolic disturbance represents a complex process only partly understood. The purpose of this study was to identify variations in plasma proteome after a high-fat challenge in healthy middle-aged men.

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The aim of the study was to delineate and compare the proteomic maps of two muscles of dry-cured ham: the biceps femoris and the semimembranosus. For this purpose, we used two-dimensional electrophoresis on a subcellular muscle fraction: insoluble protein in low ionic strength buffer. After protein identification by MALDI-TOF mass spectrometry and bioinformatic analyses, we found differences in expression levels in the two muscles.

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Proteomics allows studying large numbers of proteins, including their post-translational modifications. Proteomics has been, and still are, used in numerous studies on skeletal muscle. In this article, we focus on its use in the study of livestock muscle development and meat quality.

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Within a population of Charolais young bulls, two extreme groups of longissimus thoracis muscle samples, classified according to Warner-Bratzler shear force (WBSF) of 55 degrees C grilled meat, were analyzed by 2D-electrophoresis. Muscle analyses were performed on 4 bulls of the "tender" group (WBSF=27.7+/-4.

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