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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, Min mice, and human volunteers (crossover study). Mucin-depleted foci were scored in rats, adenoma in Min mice. Biomarkers of lipoperoxidation were measured in the feces and urine of rats, mice, and volunteers. The organoleptic properties of marinated meat were tested. Fresh beef increased colon carcinogenesis and lipoperoxidation in rats and mice and lipoperoxidation in humans. Without an adverse organoleptic effect on meat, marinade normalized peroxidation biomarkers in rat and mouse feces, reduced peroxidation in human feces and reduced the number of Mucin-depleted foci in rats and adenoma in female Min mice. This could lead to protective strategies to decrease the colorectal cancer burden associated with red meat consumption. Cancer Prev Res; 11(9); 569–80. ©2018 AACR.

Supplementary figure, tables and results Supplementary Figure S1. Flowchart of the 6 studies Supplementary Table S1. Transitions and collision energies used for the quantification (Bold) and confirmation (Italic) of AAH on the triple quadrupole instrument. Supplementary Table S2. Active compounds (extract, molecule and family), used quantity and radical scavenger activity results of marinade used in the study 1. Supplementary Table S3. Effect of grape-olive marinade and of cooking on lipid peroxidation (TBARs) and on iron levels in fresh red meats. Data are presented as mean {plus minus} SD. a two-way ANOVA assessing marinade and cooking factors. Supplementary Table S4. Effect of meat, marinade and cooking on heme content and lipoperoxidation biomarkers in feces from rats fed a no-meat control diet or experimental red meats for 14 days. Data are presented as mean {plus minus} SD. a The effect of meat intake was evaluated by a one-way ANOVA and the effect of marinated and cooked meat intake by two-way ANOVA.

ScopeEpidemiological and experimental evidence reported that processed meat consumption is associated with colorectal cancer (CRC) risk. Several studies suggest the involvement of nitrite or nitrate additivesvia N-nitroso-compound formation (NOCs).Methods and resultsCompared to the reference level (120 mg/kg of ham), the effects of sodium nitrite reduction (90 mg/kg of ham), removal and replacement were analysed on ham characteristics and in a CRC rat model. Sodium nitrite removal and reduction induced a similar decrease in CRC preneoplastic lesions, but only reduction led to (i) an inhibitory effect onListeria monocytogenesgrowth comparable to that obtained using the reference nitrite level of 120 mg/kg and (ii) an effective control of lipid peroxidation. Among the three alternatives tested, none led to a significant gain when compared to the 120 mg/kg ham reference level: vegetable stock, due to nitrate presence, was very similar to this reference nitrite level, yeast extract induced a strong luminal peroxidation and no decrease in preneoplastic lesions despite the absence of NOCs, and polyphenol rich extract induced the clearest downward trend on preneoplastic lesions but the concomitant presence of nitrosyl iron in feces. Except vegetable stock, other alternatives were less efficient than sodium nitrite (≥ 90 mg/kg) in reducingL. monocytogenesgrowth.ConclusionNitrite reduction (90mg/kg) effectively reduced CRC risk through limiting NOC formation and lipid peroxidation, while mitigatingL. monocytogenesrisks from cooked hams. Going further in reduction should be possible if accompanied by antioxidants to limit lipid peroxidation and appropriate use-by dates.

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International audience; This article critically reviews the current state of knowledge on the quality of animal-source foods according to animal production and food processing conditions, including consumer expectations-behaviours and the effects of consumption of animal-source foods on human health. Quality has been defined through seven core attributes: safety, commercial, sensory, nutritional, technological, convenience, and image. Image covers ethical, cultural and environmental dimensions associated with the origin of the food and the way it is produced and processed. This framework enabled to highlight the priorities given to the different quality attributes. It also helped to identify potential antagonisms and synergies among quality attributes, between production and processing stages, and among stakeholders. Primacy is essentially given to commercial quality attributes, especially for standard commodity animal-source foods. This primacy has strongly influenced genetic selection and farming practices in all livestock commodity chains and enabled substantial quantitative gains, although at the expense of other quality traits. Focal issues are the destructuration of chicken muscle that compromises sensory, nutritional and image quality attributes, and the fate of males in the egg and dairy sectors, which have heavily specialised their animals. Quality can be gained but can also be lost throughout the farm-to-fork continuum. Our review highlights critical factors and periods throughout animal production and food processing routes, such as on-farm practices, notably animal feeding, preslaughter and slaughter phases, food processing techniques, and food formulation. It also reveals on-farm and processing factors that create antagonisms among quality attributes, such as the castration of male pigs, the substitution of marine-source feed by plant-based feed in fish, and the use of sodium nitrite in meat processing. These antagonisms require scientific data to identify trade-offs among quality attributes and/or solutions to help overcome these tensions. However, there are also food products that value synergies between quality attributes and between production and processing phases, particularly Geographical Indications, such as for cheese and dry-cured ham. Human epidemiological studies have found associations between consumption of animal-source foods and increased or decreased risk for chronic non-communicable diseases. These associations have informed public health recommendations. However, they have not yet considered animal production and food processing conditions. A concerted and collaborative effort is needed from scientists working in animal science, food process engineering, consumer science, human nutrition and epidemiology in order to address this research gap. Avenues for research and main options for policy action are discussed

International audience; In the elderly, oral functions are modified by changes in muscular force or saliva production among others, resulting in inadequate food fragmentation which potentially impacts on oral and gastrointestinal digestion. The purpose of this work was to evaluate the consequences of oral deficiencies on the starch and protein digestibility of bread. In vitro boluses were prepared with the AM 2 masticator using normal and deficient mastication programming. Normal mastication (NM) and deficient mastication in terms of force (DfM), saliva (DsM), and their combination (DfsM) were performed. Static in vitro digestion, simulating physiological conditions in the elderly, were carried out. Bolus particle size, starch and protein digestibility, Fourier-transform infrared (FTIR) spectroscopy, and microstructure after in vitro oral and gastrointestinal digestion were analysed. More compacted boluses were observed after deficient mastication combined with greater particle sizes. The poorly fragmented boluses obtained with deficient mastication affected the oral digestion of starch, probably due to lower saliva impregnation. Digesta from deficient mastication boluses exhibited lower D-glucose release and degree of protein hydrolysis. FTIR results in the carbohydrates region also revealed weaker initiation of oral digestion of starch in DsM and DfsM boluses. These results on bread demonstrate for the first time how oral deficiencies modify nutrient bioaccessibility and, therefore, stress the importance of designing foods for specific populations such as the elderly.

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.

International audience; The elderly population will increase sharply in the future, along with an emerging range of specific nutritional needs that include adapted food. We aimed to develop a workflow to study the fate of a food,objectify the bioavailability of nutrients in the case of the digestive physiology of the elderly, and modelthe fate of proteins in the stomach. Pork frankfurters were subjected to in vitro normal and deficient mastication and gastric digestion, mimicking adult and elderly food oral and digestive processing. Swallowablefood boluses were characterized for granulometric and rheological properties. Biochemical analyses wereconducted on the bolus and on the digesta. Macronutrients, label-free peptide quantification and identification were performed, and modeling was applied to protein digestion kinetics. After deficient mastication, the food bolus was harder with more large particles, lower free iron release and more protein oxidation. The amount of peptides released in the stomach progressively increased, but to a lower extent forthe elderly digestive condition and irrespective of masticatory efficiency. 592 peptides were identifiedfrom 67 proteins. Different trajectories were observed for adult and elderly digestive conditions, and twogroups of meat proteins were identified based on the rate of hydrolysis. Designing suitable foods requiresin vitro tools to evaluate the possible benefit for the elderly. Besides the well-known notion of Food OralProcessing (FOP), our work broadens the concept by extending oral activity to digestion when working ina nutritional context. This new concept is named Food Oral and Digestive Processing, FODP.

International audience; 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. Indeed, the physicochemical conditions of the stomach (oxygen pressure, low pH) favor oxidation. In that respect, digestive proteases may be affected as well. Yet, very little is known about the link between endogenous oxidation of digestive enzymes, their potential denaturation, and, therefore, food protein digestibility. Thus, the objective of this study is to understand how oxidative chemical processes will impact the pepsin secondary structure and its hydrolytic activity. The folding and unfolding kinetics of pepsin under oxidative conditions was determined using Synchrotron Radiation Circular Dichroism. SRCD gave us the possibility to monitor the rapid kinetics of protein folding and unfolding in real-time, giving highly resolved spectral data. The proteolytic activity of control and oxidized pepsin was investigated by MALDI-TOF mass spectrometry on a meat protein model, the creatine kinase. MALDI-TOF MS allowed a rapid evaluation of the proteolytic activity through peptide fingerprint. This study opens up new perspectives by shifting the digestion paradigm taking into account the gastric digestive enzyme and its substrate.

Nitrite and nitrate are added to cured meat for their bacteriological, technological and sensorial properties. However, they are suspected to be involved in the formation of nitroso compounds (NOCs), such as potentially mutagenic nitrosamines, nitrosylheme and nitrosothiols. Controlling the sanitary and sensorial qualities of cured meat products by reducing these additives requires elucidating the mechanisms involved in the formation of NOCs. To this end, we studied the dose-response relationship of added sodium nitrite and/or sodium nitrate (0/0, 80/80, 0/200, and 120/120 ppm) on the formation of NOCs in dry cured fermented sausages. The results showed a basal heme iron nitrosylation in the absence of NaNO2/NaNO3 due to starter cultures. This reaction was promoted by the addition of NaNO2/NaNO3 in the other conditions. Reducing the dose to 80/80 ppm still limits lipid oxidation without the formation of non-volatile nitrosamines. Conversely, the addition of NO2/NO3 slightly increases protein oxidation through higher carbonyl content. The use of 80/80 ppm could be a means of reducing these additives in dry-cured fermented meat products.

Collagen antioxidant peptides are being widely studied. However, no research has paid attention to biological parameters such as the age and anatomy of collagen-rich tissues, which can determine a change in tissue structure and composition, and then in bioactivity. Moreover, only few research works have studied and assessed peptides antioxidant activity on the food matrix. This work aimed to investigate the effect of bovine&rsquo, s bone age and anatomy, and of six different enzymes, on the antioxidant activity of collagen peptides. Collagen was extracted from young and old bovine femur and tibia, six different enzymes were used for peptides&rsquo, release. The redox potential, the quenching of stable free radicals, and the antioxidant capacity on bovine meat lipids and proteins was evaluated, under heating from ambient temperature to 80 &deg, C. Age and anatomy showed a significant effect, the influence of anatomy becomes most important with age. Each enzyme&rsquo, s effectiveness toward age and anatomy was not the same. The greatest amount of peptides was released from young bones&rsquo, collagen hydrolysed with papain. The antioxidant activity was higher at higher temperatures, except for meat proteins. Assessing the effect of age and anatomy of collagen-rich tissues can promote a better application of collagen bioactive peptides.

International audience; 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. At the end of the gastric and intestinal phase, global measurements of digestibility and antioxidant bioactivities were performed. The statistical analysis workflow developed allowed: (i) synthesizing the compositional and nutritional information of each protein extract by creating latent variables, and (ii) comparing them. The links between variables and similarities between protein extracts were visualized using a heat map. A hierarchical cluster analysis allowed reducing the 48 quantitative variables into 15 qualitative latent variables (clusters). The application of the k-means method on each cluster enable to classify the protein extracts by level. This defined level was used as categorical value. Multiple correspondence analysis revealed groups of protein extracts with varied patterns. This workflow allowed the comparison/hierarchization between protein extracts and the creation of a tool to select the most interesting ones on the basis of their nutritional quality.

International audience; 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. Bioinformatics tools (e.i. BIOPEP and Uniprot) permitted to orientate the choice of enzymes for generating abundant bioactive peptides from the four studied porcine products. With papain and subtilisin, the main bioactivities potentially released were ACE inhibitors, DPP4 inhibitors and antioxidant peptides. An in vitro validation study using papain and subtilisin demonstrated high DPP4 inhibitors and antioxidant bioactivities for the generation of peptides. This work allowed: i) the identification of all proteins that composed porcine heart, liver, lung and LD muscle that could be useful for the scientific community, ii) the development of a workflow to select most abundant proteins in a product while considering abundance factors and iii) the potential of porcine meat and offals to generate DPP4 inhibitors and antioxidant peptides. However, there is still a need in developing new tools in order to face limitations of mass spectrometry for the identification of peptides with less than six amino acids. Such a work may contribute to the development of the circular economy and the innovative creation of value-added products from animal production.

International audience; PSE-like muscle defect is of great importance in the cooked ham industry because of the economic losses it can cause. Although this muscle defect has been widely studied from a mechanistic angle, there is a lack of reliable and practical markers. This study proposes the use of chemometrics for the spectral fingerprinting of pig plasma to predict the PSE-like muscle defect in cooked hams. Both MALDI-TOF mass spectrometry and ATR-FTIR spectroscopy were used to obtain protein and chemical function fingerprints. Though the two approaches showed very good predictive capacity, MALDI-TOF mass spectrometry was found to be better suited to predicting normal hams, i.e. hams without the defect; while ATR-FTIR spectroscopy was found to be better suited to predicting the PSE-like muscle defect. These results demonstrated the feasibility of predicting the PSE-like defect using spectral fingerprinting and chemometrics approaches.

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, Min mice, and human volunteers (crossover study). Mucin-depleted foci were scored in rats, adenoma in Min mice. Biomarkers of lipoperoxidation were measured in the feces and urine of rats, mice, and volunteers. The organoleptic properties of marinated meat were tested. Fresh beef increased colon carcinogenesis and lipoperoxidation in rats and mice and lipoperoxidation in humans. Without an adverse organoleptic effect on meat, marinade normalized peroxidation biomarkers in rat and mouse feces, reduced peroxidation in human feces and reduced the number of Mucin-depleted foci in rats and adenoma in female Min mice. This could lead to protective strategies to decrease the colorectal cancer burden associated with red meat consumption. Cancer Prev Res; 11(9); 569–80. ©2018 AACR.

International audience; We studied the kinetics of peptide release during the gastric digestion of meat proteins in vivo, in view to predicting the release of bioactive peptides further on in the digestive tract. Six mini pigs fitted with gastric cannulas received a meal with cooked beef as protein source. Digesta was collected at regular time intervals up to 5½ h. The peptides generated by the gastric digestion of meat were identified and quantified using label-free LC MS, thereafter subjected to in silico digestion mimicking the action of intestinal enzymes. Three clusters of proteins presenting similar evolutions according to their dynamic hydrolysis were obtained. This study clearly improves the in silico prediction of the intestinal release of bioactive peptides by mapping meat protein degradation in the stomach in an in vivo model. Knowledge of the conformation of the peptides released in the stomach further improves this prediction.

Synchrotron radiation circular dichroism (SRCD) and Fourier transform infrared (FTIR) spectroscopy were used to examine the conformation evolution of micellar casein (MC) powder during storage and to determine whether the spectral changes could be related to their solubility evolution.; Results: A loss in intensity of SRCD spectra as a function of storage time has been observed. Quantification of secondary structures revealed losses of α-helix content during storage. Moreover, a redshift of the amide I band in the FTIR spectrum was demonstrated during the storage and was interpreted as a rearrangement of the secondary structure of the protein, which is in line with the SRCD results. The qualitative results obtained by FTIR clearly support the quantitative evolution of the secondary structure obtained by the analysis of SRCD spectra. Principal component analysis (PCA) of FTIR spectra permits a good separation of samples according to the storage time. PCA shows that the evolution of secondary structures and solubility loss are closely linked.; Conclusion: With the quantitative data provided by SRCD spectra, it was established that, whatever the storage conditions, a unique curve exists between loss of α-helix content and loss in solubility, showing that loss of α-helix content is a marker of solubility loss for the MC powders studied. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

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. Variability of physicochemical properties of collagen extracted from bovine bone by acetic acid was then investigated taking into account endogenous and exogenous factors. Endogenous: bovine’s bones age (4 and 7 years) and anatomy (femur and tibia); exogenous: thermal treatments (spray-drying and lyophilisation). Scanning electron microscopy, spectroscopy (EDS, FTIR, UV/Vis and CD), differential scanning calorimetry (DSC), centesimal composition, mass spectrometry, amino acids and zeta-potential analysis were used for the purpose. Age correlated negatively with yield of recovery and positively with minerals and proteoglycans content. Comparing the anatomy, higher yields were found for tibias, and higher stability of tibias collagen in solution was noticed. Whatever the age and the anatomy, collagens were able to renature and to self-assemble into tri-dimensional structures. Nonetheless thermal stability and kinetics of renaturation were different. Variability of natural collagen with bone age and anatomy, and drying methodology, may be a crucial advantage to conceive tailor-made applications in either the biological or technical sector.

International audience; Preparing a food bolus for swallowing is the first and major goal of oral processing ensured by mastication. To fulfill this goal, mastication is accurrately adjusted to the structure and texture of the food. Since the bolus is the main outcome of food oral processing, there is growing interest in improving understanding the food bolus and its features at the end of the masticatory sequence and throughout its formation. Although this step is trivial, its execution is somewhat more complex than it appears. Until now, the food bolus produced has not subjected to full analysis, mainly due to the lack of accessibility during in vivo oral processing. To overcome this difficulty, we developed a masticator apparatus, named AM2, on the basis of in vivo compression and shear stresses applied on food during oral processing. The apparatus was validated against particle size analyses of boluses produced by individuals presenting normal mastication. The present paper provides a comprehensive overview of the various potential uses of the AM2 apparatus to produce food boluses for a large range of scientific needs. The food bolus contains much valuable information regarding the progress of mastication, the completion of the function and its role in food disruption, the oral release of food compounds, changes and bioaccessibility, and finally its impact on nutrition. The AM2 apparatus can also be used to simulate mastication in specific populations, such as the elderly and children, and to address various objectives related to this initial step of digestion.

The ambition of the foresight on livestock farming was to rethink the place, the roles of livestock and how it should be transformed to fully contribute to the development of more sustainable agri-food systems. It was also to identify cross-disciplinary research themes that explore promising fronts of science or methodologies to solve knowledge locks. The foresight was managed by a group of 15 researchers and mobilized a hundred researchers. Based on an analysis of the context and the drivers for the evolution of the systems, we propose a new conceptual framework to think about innovations. Livestock farming must be part of circular agri-food systems in which it must contribute, beyond an increased efficiency of production factors, to the preservation of the quality of the resources and to the production of a food at an affordable price. Systems need to be rethought to be climate-smart and to respond to the health and welfare challenges of animals and people, rethink the linkages between livestock, crop production and territories to maximize recycling and rethink livestock linkages, processing and consumption of livestock products. Innovations should be based on the principles of agro-ecology supplemented by those of the circular economy and mobilizing levers of (bio) technologies and organizational innovation. The text describes 4 major scientific priorities with their research issues and produces recommendations for an action plan., L’ambition de l’Atelier de Réflexion Prospective sur l’élevage a été de repenser la place, les rôles de l’élevage et en quoi il doit se transformer pour contribuer pleinement au développement de systèmes agri-alimentaires plus durables ainsi que d’identifier des thématiques de recherches interdisciplinaires permettant d’explorer des fronts de science ou méthodologiques porteurs d’avenir pour lever les verrous de connaissances. La réflexion a été animée par un groupe de 15 chercheurs et en a mobilisé une centaine. À partir d’une analyse du contexte et des drivers d’évolution des systèmes nous proposons un nouveau cadre conceptuel et des voies de progrès pour penser l’élevage de demain. L’élevage doit s’inscrire dans le cadre de systèmes agri-alimentaires circulaires dans lesquels il doit contribuer, au-delà d’une efficience accrue des moyens de production, à la préservation de la qualité des ressources et à la production d’une alimentation à un prix abordable. Il faut repenser les systèmes pour qu’ils soient climato-intelligents et répondent aux enjeux de santé et du bien-être des animaux et des Hommes ; repenser les liens entre élevage, production végétale et territoire pour maximiser les recyclages et repenser les liens entre élevage, transformation et consommation des produits de l’élevage. Les innovations doivent être basées sur les principes de l’agroécologie complétés par ceux de l’économie circulaire et par la mobilisation des leviers des (bio)technologies et de l’innovation organisationnelle. Le texte décrit quatre grandes priorités scientifiques avec leurs enjeux de recherche et produit des recommandations pour un plan d’action.

International audience; 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. This study focused on muscle destructuration using imaging and label-free quantitation. Oxidative stress and apoptotic processes were found to be linked to the specific evolution of the PSE-like destructuration zone, namely ‘inner’, within hams. Four m/z values were found to be related to the specific localization of the PSE-like defect, and a mass shift of 27 Da suggested a possible connection with oxidation. These potential markers of the PSE-like area in ham provide a new perspective to sort raw material based on the possible development of PSE-like areas.

International audience; 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. This new paper completes the previous one by focusing on the endogenous heme iron nitrosylation. Low nitrosylation due to nitrate initially present in meat and to ammonia oxidation in the stomach was observed in the digestive tract even in conditions in which no nitrite was added to the model. The endogenous addition of nitrite (1 mM) considerably increased heme iron nitrosylation while a significant decrease was observed with prior meat cooking (30 min at 60 and 90 °C).

International audience; Livestock generates high quantities of residues, which has become a major socioeconomic issue for the meat industry. This review focuses on the identification of bioactive peptides (BPs) in animal byproducts and meat wastes. Firstly, the main bioactivities that peptides can have will be described and the methods for their evaluation will be discussed. Secondly, the various origins of these BPs will be studied. Then, the techniques and tools for the generation of BPs will be detailed in order to discuss, in the final part, how peptides could be used and assimilated. BPs possess diverse biological activities and can be strategic candidates for substituting synthetic molecules. In silico potentiality studies are a helpful tool to understand and predict BPs released from proteins and their potential activities. However, in vitro validation is often required. Although BP use is compelled by strict regulations in relation to the field of application, they are also limited by their low bioavailability and bioaccessibility. Therefore, it is important to test peptide stability during gastrointestinal digestion. Protective strategies have been discussed since their use could improve the stability and effectiveness of BPs.

Background: Cooking may impair meat protein digestibility. When undigested proteins are fermented by the colon microbiota, they can generate compounds that potentially are harmful to the mucosa. Objectives: This study addressed the effects of typical cooking processes and the amount of bovine meat intake on the quantity of undigested proteins entering the colon, as well as their effects on the intestinal mucosa. Methods: Male Wistar rats (n = 88) aged 8 wk were fed 11 different diets containing protein as 20% of energy. In 10 diets, bovine meat proteins represented 5% [low-meat diet (LMD)] or 15% [high-meat diet (HMD)] of energy, with the rest as total milk proteins. Meat was raw or cooked according to 4 processes (boiled, barbecued, grilled, or roasted). A meat-free diet contained only milk proteins. After 3 wk, rats ingested a 15N-labeled meat meal and were killed 6 h later after receiving a 13C-valine injection. Meat protein digestibility was determined from 15N enrichments in intestinal contents. Cecal shortand branched-chain fatty acids and hydrogen sulfide were measured. Intestinal tissues were used for the assessment of protein synthesis rates, inflammation, and histopathology. Results:Meat protein digestibility was lower in rats fed boiled meat (94.5%6 0.281%) than in the other 4 groups (97.5%6 0.0581%, P < 0.001). Cecal and colonic bacterial metabolites, inflammation indicators, and protein synthesis rates were not affected by cooking processes. The meat protein amount had a significant effect on cecal protein synthesis rates (LMD > HMD) and on myeloperoxidase activity in the proximal colon (HMD > LMD), but not on other outcomes. The ingestion of bovine meat, whatever the cooking process and the intake amount, resulted in discrete histologic modifications of the colon (epithelium abrasion, excessive mucus secretion, and inflammation). Conclusions: Boiling bovine meat at a high temperature (100C) for a long time (3 h) moderately lowered protein digestibility compared with raw meat and other cooking processes, but did not affect cecal bacterial metabolites related to protein fermentation. The daily ingestion of raw or cooked bovine meat had no marked effect on intestinal tissues, despite some slight histologic modifications on distal colon.

International audience; Huge amounts of animal by-products are generated along processing for human consumption. This material adds up to 50% of the animal weight, representing a serious economic and environmental concern. Scope and approach: A shift to a molecular level of utilisation of those residues could be a viable and cost-effective option, where the biomolecules recovered would be applied outside the agricultural sector. In this regards, the structural fibrous proteins collagen, elastin and keratin, and respective hydrolysates and small peptides, can be recovered from fisheries, poultry and red meat slaughter residues and employed in high-priority fields such as food, biomedicine and pharmaceutics, and in highly profitable areas such as cosmetics. Bones (from fish and meat), skin (from pig and fish) and fish scales are a source of collagen; ligaments (from cattle, pig and poultry) are a source of elastin while keratin could be recovered from poultry feathers and pig hair. Beside the documented relevance of collagen, elastin and keratin in cosmetic and pharmaceutics, and of gelatine in the food and photographic industry, a number of new applications can look at them as promising ingredients. Key findings and conclusions: The spontaneous self-assembly of the native alpha-helix of collagen, elastin and keratin allows conceiving biomaterials, emulsions, foams, stable colloids, as well as micro- and nano capsules. Alongside this, the biological activities of small peptides, such as the antihypertensive, antimicrobial, antioxidant, wound-healing, osteogenic, haemostatic and chelating capacity, give the possibility to look at animal by-products as a remarkable source of functional compounds, whose application will contribute to the agro-food industry sustainability.

International audience; In humans, meat ensures the supply of proteins with high nutritional value and indispensable amino acids. The main goal of the present study was to compare the degradation of meat proteins in adult and elderly digestive conditions. Cooked meat was subjected to in vitro digestion in the dynamic multi-compartmental TIM (TNO gastroIntestinal Model) system. Digestibility and bioaccessibility were determined using nitrogen balance and digestion products were identified using mass spectrometry. The TIM model was adapted according to in vivo data to mimic the specific digestive conditions of elderly people. Meat protein digestibility and bioaccessibility were around 96 and 60% respectively and were not influenced by age (P > 0.05). As much as 800 peptides were identified in the duodenal and jejunal compartments issued from 50 meat proteins with a percentage of coverage varying from 13 to 69%. Six proteins, mainly from the cytosol, were differentially hydrolyzed under the adult and elderly digestive conditions. Pyruvate kinase was the only protein clearly showing a delay in its degradation under elderly digestive conditions. This study provides significant insights into the understanding of meat protein dynamic digestion. Such data will be helpful to design in vivo studies aiming to evaluate dietary strategies that can attenuate muscle mass loss and more generally maintain a better quality of life in the elderly population.

Introduction et but de l’etude Le vieillissement peut s’accompagner d’une baisse du flux salivaire et du nombre de dents entrainant une moindre consommation de viande avec un risque de denutrition et de fonte musculaire. Ainsi, pour augmenter la consommation de proteines chez les seniors, il est important de proposer des aliments carnes adaptes a leurs capacites orales. Dans ce contexte, le but de ce travail est d’objectiver le confort en bouche lors de la prise d’aliments developpes specifiquement chez deux populations seniors a l’etat buccodentaire contraste. Materiel et methodes Deux groupes de sujets (> 65 ans et vivant a domicile), 36 (18H, 18F) presentant une bonne dentition (BD, âge = 73 ± 5, UFP (unites fonctionnelles posterieures)= 8 ± 1) et 36 (15H, 21F) une mauvaise dentition (MD, âge = 74 ± 5, UFP = 3 ± 1) ont ete choisis. Les deux groupes sont sans risque de denutrition (MNA = 27,4 ± 0,3). Ils ont un flux salivaire stimule (FSS) non different entre BD et MD et de moyenne globale 1,8 ± 0,7 mL/min. Deux matrices, bœuf (Bo) et poulet (Po), elaborees selon un meme procede, ont ete evaluees (bouchee de 6 g) deux fois au moyen d’un questionnaire sensoriel divise en 5 parties [1] , [2] : confort en bouche et facilite a manger, facilite a former un bol, douleurs ressenties, texture et flaveur. Les donnees ont ete traitees par ANCOVA (2 facteurs categoriels [(Bo, Po) et (BD, MD)] + 1 facteur continu [FSS]). Resultats et analyse statistique Exprimes sur une echelle de 0 a 100, les resultats montrent que les sujets MD jugent les 2 matrices plus confortables en bouche que les sujets BD (75 ± 1,8 et 71 ± 1,8, F = 6,1, p La comparaison entre les matrices souligne que Po est juge plus confortable que Bo (77 ± 1,8 et 68 ± 1,8, F = 10,7, p Il n’y a pas d’effet significatif du FSS sur l’evaluation du confort. Conclusion Le resultat remarquable de cette etude est que les sujets avec un mauvais etat bucco-dentaire jugent les produits plus confortables et plus faciles a manger que les sujets normo-dentes. Globalement, les procedes de fabrication permettent d’obtenir deux viandes confortables en bouche, la matrice de poulet etant jugee encore plus confortable que celle de bœuf. La suite de ce travail portera sur les caracteristiques structurales et biochimiques du bol alimentaire forme par la mastication pour ces deux groupes de seniors et sur leur lien avec la perception du confort et la digestibilite des deux matrices carnees.

International audience; 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. Peptides and proteins from gastrointestinal digestion were identified by high-resolution LC-MS/MS mass spectrometry. The results showed a dynamic digestion pattern of meat proteins according to their cellular localization. A combined effect of the digestive compartment and the addition of nitrite was established for the first time on peptides profile, linking the nitrosation of proteins and their digestibility.

International audience; The gelatin used for the hard capsules manufacturing must meet strict dissolution specification to ensure the delivery of drugs at right time in the digestive tract. However, the environment of production and storage time affect the quality of gelatin dissolution. This study aimed to identify the mechanisms underlying the geographical environment of production and aging impact on the gelatin dissolution rate. Gelatins from 3 different origins of production (A, B & C), whose dissolution rate had been previously characterized, were analyzed by Raman microspectroscopy before and after aging. The principal component analysis (PCA) clearly separated the aged gelatins from non-aged ones. The spectra interpretation suggested the denaturation of gelatin triple-helices. In addition, the formation of cross-links such as dityrosine, glucosyl-galactosylhydroxylysinonorleucine and proteoglycan-like sugar adducts was strongly suspected. Whatever the gelatin aging state, PCA systematically separated the B-gelatins from A and C-gelatins. Pentosidine cross-link was likely to vary depending on the production origin. Finally, the quality of dissolution was discriminated for aged gelatins of A-origin: the non-compliant gelatins exhibited higher lipid content than the compliant ones.

International audience; Fruit and vegetables (F&V) polyphenols have numerous positive health effects, ascribed either to their antioxidant activity within the gastrointestinal tract (GIT) or to bioactivity of their absorbed metabolites. The effect of the F&V matrix on the gastrointestinal bioaccessibility of polyphenols was investigated along with its possible interaction with protein digestion. Minipigs were fed a complete meal with either cubed F&V (apple, plum, artichoke) added, or the corresponding phenolic extract (PE). Gastric and ileal chymes were kinetically collected over the postprandial period. The overall polyphenol bioaccessibility in the stomach was found to be 1.5% and 3.1% after F&V and PE consumption, respectively. The lower release rate from artichoke than from apple showed evidence of a plant effect. Flavanol monomers and glucoside conjugates were not recovered in the ileum in agreement with their absorption in the upper GIT. Interestingly, PE, but not F&V, significantly decreased the speed and efficiency of dietary protein digestion.

In the elderly, masticatory function often presents failure in certain oral tasks due to impairment such as decline in muscular force, jaw or tongue motility, neuro-muscular coordination, tooth damage, malocclusion and saliva production. Great disparity is observed in the various and potentially cumulative oral declines that occur with ageing. Such difficulties may have an impact on food consumption and nutritional status. To obtain better understanding of the consequences of several oral deficiencies, a series of swallowable boluses were prepared in vitro with the AM2 masticator apparatus with normal and deficient programming. Physiological normal mastication (NM) was simulated using in vivo data from healthy subjects. Chewing deficiencies were reproduced by alteration of NM programming to perform different levels and combinations of force loss, lack of saliva and decrease in the motility of oral elements. Poultry meatballs were used as test-food. Particle size distribution in the food bolus was measured by sieving and rheological features (hardness, cohesiveness and elasticity) were assessed with a TPA test. Compared to the NM outcome, significant and gradual deterioration of the food bolus was observed and associated with alteration in force, saliva and motility. Combinations of several failures led to greater or cumulative deficiencies in swallowable bolus properties. For the elderly presenting a high prevalence of various oral injuries, tailoring textured food cannot be ignored as a solution for remedying deficiencies and favoring the formation of a safe-swallowable bolus, which is an essential vector of nutrients. Knowing the impacts of oral injuries on the food bolus is obviously a requisite for developing diet strategies, including nutritional items for specific populations.

International audience; Chemical changes that occur during the storage and processing of food can affect its nutritional content. During digestion, the exposure of food to considerable variations of pH and high oxygen and peroxide concentrations also participates in the deterioration of nutrients, with a negative impact on the nutritional value of the diet and harmful consequences for human health. Iron plays a key role in gastrointestinal chemistry. Haem iron, which exists only in meat, and non-haem iron, present in most foods, are catalysts of most of the reactions implicated in the deterioration of nutrients. Disintegration of food matrix due to mechanical forces and enzymatic hydrolysis favour this endogenous process. This paper provides a review of what is known in the literature concerning the mechanisms and kinetics of endogenous reactions catalysed by iron. The main consequences on nutrient bioavailability are reported and protective strategies against the deleterious effect of iron are discussed.