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International audience; Processed meat intake is carcinogenic to humans. We have shown that intake of a workshop-made cured meat with erythorbate promotes colon carcinogenesis in rats. We speculated that polyphenols could inhibit this effect by limitation of endogenous lipid peroxidation and nitrosation. Polyphenol-rich plant extracts were added to the workshop-made cured meat and given for 14 days to rats and 100 days to azoxymethane-induced rats to evaluate the inhibition of preneoplastic lesions. Colons of 100-d study were scored for precancerous lesions (mucin-depleted foci, MDF), and biochemical end points of peroxidation and nitrosation were measured in urinary and fecal samples. In comparison with cured meat-fed rats, dried red wine, pomegranate extract, a-tocopherol added at one dose to cured meat and withdrawal of erythorbate significantly decreased the number of MDF per colon (but white grape and rosemary extracts did not). This protection was associated with the full suppression of fecal excretion of nitrosyl iron, suggesting that this nitroso compound might be a promoter of carcinogenesis. At optimized concentrations, the incorporation of these plant extracts in cured meat might reduce the risk of colorectal cancer associated with processed meat consumption.

International audience; The influence of four heat-processing regimes and a storage phase on the behaviour of Listeria monocytogenes in ground pork was studied. The effects of pH and water activity (aw) were also tested. During the heat process phase, aw, the heat-processing regime and its interactions with pH or aw, had a significant effect on the behaviour of L. monocytogenes. During the storage phase, all parameters tested and their interactions had significant effects. Nevertheless, the area in which the growth of L. monocytogenes was observed at the end of the experiment was not influenced by the heat-processing regime tested. On the contrary, pH, aw and their interactions had significant effects on Listeria behaviour. The boundary of the growth area delimited by environmental conditions where growth was higher than 1.0 Log CFU g)1 from those where growth was lower than this limit was correctly predicted by Augustin’s model.

This review is respectfully dedicated to the memory of Michel Ollivon, Research Director at CNRS (Châtenay-Malabry, France), outstanding physico-chemist specialist of lipid organization, recipient of the Hilditch Memorial Lecture award, who was the initiator of the network RMT LISTRAL. We are also sadly paying tribute to Jean-Luc Vendeuvre, Food Engineer at the French Pork and Pig Institute (IFIP, Maisons-Alfort, France), outstanding expert in meat products who participated actively in RMT LISTRAL and provided unpublished data for figures in the present review, who passed away during review submission. RMT LISTRAL: Mixed Technological Network combining academic and industrial partners, devoted to the enhancement and divulgation of knowledge regarding structured dietary lipids.; International audience; On a nutritional standpoint, lipids are now being studied beyond their energy content and fatty acid (FA) profiles. Dietary FA are building blocks of a huge diversity of more complex molecules such as triacylglycerols (TAG) and phospholipids (PL), themselves organised in supramolecular structures presenting different thermal behaviours. They are generally embedded in complex food matrixes. Recent reports have revealed that molecular and supramolecular structures of lipids and their liquid or solid state at the body temperature influence both the digestibility and metabolism of dietary FA. The aim of the present review is to highlight recent knowledge on the impact on FA digestion, absorption and metabolism of: (i) the intramolecular structure of TAG; (ii) the nature of the lipid molecules carrying FA; (iii) the supramolecular organization and physical state of lipids in native and formulated food products and (iv) the food matrix. Further work should be accomplished now to obtain a more reliable body of evidence and integrate these data in future dietary recommendations. Additionally, innovative lipid formulations in which the health beneficial effects of either native or recomposed structures of lipids will be taken into account can be foreseen.

The analysis of the aroma of a food product requires the extraction of its volatile compounds. As the composition of the extract obtained depends on the extraction method, it is important to verify that the odour actually extracted is representative of the product. This verification is particularly relevant in the case of cooked cured ham, as its odour is not very strong as compared to other cured products (dry cured ham or sausage). Extracts were obtained by four different vacuum distillation processes. A sensory comparison of the odour of these extracts with the reference product was performed by ten trained panelists. The odour similarity of the extracts with the reference was assessed in order to select the most representative one, upon defined descriptors. Direct vacuum distillation of ground ham suspended in water was selected as the most representative. Gas chromatography (GC)-olfactometry, a technique of choice to identify potent odorants in food products, was then planned. As one of the key point of this analysis is to correlate the Flame Ionization Detector (FID) detection to the sniffing one, a problem very often underestimated by authors, a GC-olfactometric study of a model mixture was first performed with three selected people. FID and sniffing detection of this model mixture were compared in terms of retention time reproducibility. Standard deviation of retention indices observed for sniffing and FID detection were found in the same range. Retention indices calculated with both detections differed within a confidence interval of ± 3 index values. FID and odour detection were found to be correlated within this interval.

Epidemiology suggests that processed meat is associated with colorectal cancer risk, but few experimental studies support this association. We have shown that a model of cured meat made in a pilot workshop promotes preneoplastic lesions, mucin-depleted foci (MDF) in the colon of rats. This study had two aims: to check if real store-bought processed meats also promote MDF, and to test if calcium carbonate, which suppresses heme-induced promotion, can suppress promotion by processed meat. A 14-day study was done to test the effect of nine purchased cured meats on fecal and urinary biomarkers associated with heme-induced carcinogenesis promotion. Fecal water from rats given hot dog or fermented raw dry sausage was particularly cytotoxic. These two cured meats were thus given to rats pretreated with 1,2-dimethylhydrazine, to evaluate their effect on colorectal carcinogenesis. After a 100-d feeding period, fecal apparent total N-nitroso compounds (ATNC) were assayed and colons were scored for MDF. Hot dog diet increased fecal ATNC and the number of MDF per colon compared with the no-meat control diet (3.0±1.7 vs. 1.2±1.4, P

International audience; Background: Processed meat intake has been associated with increased colorectal cancer risk. We have shown that cured meat promotes carcinogen-induced preneoplastic lesions and increases specific biomarkers in the colon of rats. Objectives: We investigated whether cured meat modulates biomarkers of cancer risk in human volunteers and whether specific agents can suppress cured meat-induced preneoplastic lesions in rats and associated biomarkers in rats and humans. Design: Six additives (calcium carbonate, inulin, rutin, carnosol, alpha-tocopherol, and trisodium pyrophosphate) were added to cured meat given to groups of rats for 14 d, and fecal biomarkers were measured. On the basis of these results, calcium and tocopherol were kept for the following additional experiments: cured meat, with or without calcium or tocopherol, was given to dimethylhydrazine-initiated rats (47% meat diet for 100 d) and to human volunteers in a crossover study (180 g/d for 4 d). Rat colons were scored for mucin-depleted foci, putative precancer lesions. Biomarkers of nitrosation, lipoperoxidation, and cytotoxicity were measured in the urine and feces of rats and volunteers. Results: Cured meat increased nitroso compounds and lipoperoxidation in human stools (both P < 0.05). Calcium normalized both biomarkers in rats and human feces, whereas tocopherol only decreased nitro compounds in rats and lipoperoxidation in feces of volunteers (all P < 0.05). Last, calcium and tocopherol reduced the number of mucin-depleted foci per colon in rats compared with nonsupplemented cured meat (P = 0.01). Conclusion: Data suggest that the addition of calcium carbonate to the diet or alpha-tocopherol to cured meat may reduce colorectal cancer risk associated with cured-meat intake. This trial was registered at clinicaltrials.gov as NCT00994526.

Revue réalisée en hommage à Michel Ollivon (Directeur de Recherche au CNRS, UMR8612, Châtenay-Malabry), décédé en juin 2007, qui a été à l’origine de la création du RMT Listral. Ce Réseau Mixte Technologique avec pour thématique les Lipides Structurés Alimentaires est coordonné par l’ACTIA et animé par Actilait. Les autres partenaires du réseau sont : F Sobolewski & JP Bodin (Enilia-Ensmic), K Duhem & JP Guyonnet (Cniel), JP Bergé & JP Gouygou (Ifremer Nantes), G Nassy (Ifip), Lebois & D Majou (Actia), P Gaborit & R Richoux (Actilait).; National audience; From the nutrition point of view, lipids are primarily considered as energy suppliers, their dietary intake having to be limited. In fact, lipids are sources of various fatty acids, and dietary recommendations include the required daily intakes in different fatty acids (fatty acid profile). Beyond these quantitative aspects, fatty acids are part of larger molecules, mainly triacylglycerols (TAG), that are organized in supramolecular structures as for example fat crystals and lipid droplets. Recent advances in nutrition research have demonstrated that these structures, and lipid organization in food matrices, influence digestibility and metabolism of fatty acids. Therefore, the members of the technological network Listral propose a synthesis of the knowledge about the influence of molecular and supramolecular structures of lipids on digestion and metabolic fate of dietary fatty acids originating from for the main food industry sectors. Fatty acids are mainly provided in the diet in the form of TAG, or phospholipids (PL) where they are esterified in external (sn-1, sn-3) or internal (sn-2) position of the glycerol backbone. They can also be found as ethyl esters (EE) in specific formulations. These molecular characteristics of the lipid molecules affect their hydrolysis and their absorption rate but also their metabolism in indifferent organs, as assessed in studies often using inter esterified fat sources. The results depend on the types of fatty acids (saturated or polyunsaturated fatty acids) but also on the model used for the studies: in vitro or in vivo studies ; animal model, human newborn or adult, either healthy or exhibiting some diseases. Among others, it was found that the crystal form and fat melting point as affected by the fatty acid profiles and the lipid molecular structures directly impact fatty acid absorption kinetics through modifications of lipolytic enzyme activities. However, in these studies, the relative effect of the thermal properties of lipids and the proportion of saturated fatty acids chains in sn-2 position were hardly distinguished. Supramolecular structures, namely type and size of the fat droplets and their interfacial composition, of lipids, either in their native forms or obtained after food processes, also affect the digestibility and absorption of lipids. This aspect is reviewed with specific focus on dairy, marine, meat, oil plant and egg products. The impact of other nutritional components present in these food matrices on the absorption of lipids is also discussed.

Processed meat intake is associated with colorectal cancer risk, but no experimental study supports the epidemiologic evidence. To study the effect of meat processing on carcinogenesis promotion, we first did a 14-day study with 16 models of cured meat. Studied factors, in a 2 × 2 × 2 × 2 design, were muscle color (a proxy for heme level), processing temperature, added nitrite, and packaging. Fischer 344 rats were fed these 16 diets, and we evaluated fecal and urinary fat oxidation and cytotoxicity, three biomarkers of heme-induced carcinogenesis promotion. A principal component analysis allowed for selection of four cured meats for inclusion into a promotion study. These selected diets were given for 100 days to rats pretreated with 1,2-dimethylhydrazine. Colons were scored for preneoplastic lesions: aberrant crypt foci (ACF) and mucin-depleted foci (MDF). Cured meat diets significantly increased the number of ACF/colon compared with a no-meat control diet (P = 0.002). Only the cooked nitrite-treated and oxidized high-heme meat significantly increased the fecal level of apparent total N-nitroso compounds (ATNC) and the number of MDF per colon compared with the no-meat control diet (P < 0.05). This nitrite-treated and oxidized cured meat specifically increased the MDF number compared with similar nonnitrite-treated meat (P = 0.03) and with similar nonoxidized meat (P = 0.004). Thus, a model cured meat, similar to ham stored aerobically, increased the number of preneoplastic lesions, which suggests colon carcinogenesis promotion. Nitrite treatment and oxidation increased this promoting effect, which was linked with increased fecal ATNC level. This study could lead to process modifications to make nonpromoting processed meat. Cancer Prev Res; 3(7); 852–64. ©2010 AACR.

International audience; A histological and ultrastructural study was conducted to characterize changes in the muscle fibre structure of three fresh sausage preparations, depending on meat composition, sodium chloride (NaCl) and potassium lactate (K-lactate) contents. After addition of 0.8% and 1.6% NaCl, 65% and 51%, respectively, of the area observed showed well preserved fibres (histological data). The altered regions presented a large disorganization of the myofilaments and a solubilization of the sarcolemma and of the Z lines. K-lactate addition had no marked effects on meat structure. The preparation containing some sheep meat was more sensitive to salt than the others containing only bovine meat. The level of alteration was much lower than those obtained in pork meat in another study. Technological conditions used to modify the internal muscle fibre structure during sausage processing depend on the species used. Therefore, the classification of the sausage preparation to "meat preparation" or "meat product" under the EU regulation (EC) No. 853/2004 (which assign meat preparations to meat if the product has undergone a process insufficient to modify the internal muscle fibre structure of the meat) must be systematically controlled when changing the meat sausage composition.

The role of sodium nitrite on phospholipid composition was studied during the processing of cooked cured ham. Evolution of the different classes of phospholipids in raw meat, cured meat with brine injected at 0, 50 and 100 mg of sodium nitrite/kg meat, and cooked meat, was determined as well as fatty acid content of phosphatidyl choline and phosphatidyl ethanolamine in raw and cooked meat. The major effect of sodium nitrite was observed on phosphatidyl ethanolamine whose content was significantly lowered in the presence of this salt. This effect was observed at the end of the curing process and was not modified by the cooking. The fatty acid content between raw meat and cooked cured eeat showed the strongest effect of sodium nitrite on arachidonic acid, for both phosphatidyl choline and phosphatidyl ethanolamine. This fatty acid was degraded preferentially in the presence of this salt, probably due to its high level of unsaturation. Known volatile odorant compounds typical from polyunsaturated fatty acid oxidation (hexanal, oct-1-en-3-ol,…) were observed in lower amounts in cooked meat cured with sodium nitrite. The content of these volatile compounds is usually measured in order to evaluate the lipid oxidation level in meat. In our study, nitrite treated meat contained less of these compounds concomitant with a lowered phosphatidyl ethanolamine content, especially for one of its major fatty acid, arachidonic acid. Further investigations are needed to understand the oxidation route of this polyunsaturated fatty acid in the presence of sodium nitrite.