Effects of sodium nitrite reduction, removal or replacement on cured and cooked meat for microbiological growth, food safety, colon ecosystem, and colorectal carcinogenesis in Fischer 344 rats

Epidemiological and experimental evidence indicated that processed meat consumption is associated with colorectal cancer risks. Several studies suggest the involvement of nitrite or nitrate additives via N-nitroso-compound formation (NOCs). Compared to the reference level (120 mg/kg of ham), sodium nitrite removal and reduction (90 mg/kg) similarly decreased preneoplastic lesions in F344 rats, but only reduction had an inhibitory effect on Listeria monocytogenes growth comparable to that obtained using the reference nitrite level and an effective lipid peroxidation control. Among the three nitrite salt alternatives tested, none of them led to a significant gain when compared to the 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 in rats despite the absence of NOCs, and polyphenol rich extract induced the clearest downward trend on preneoplastic lesions in rats but the concomitant presence of nitrosyl iron in feces. Except the vegetable stock, other alternatives were less efficient than sodium nitrite in reducing L. monocytogenes growth

Development of meat models with fiber enrichment adapted to masticatory deficiency in Elderly

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Redox Potential and Antioxidant Capacity of Bovine Bone Collagen Peptides towards Stable Free Radicals, and Bovine Meat Lipids and Proteins. Effect of Animal Age, Bone Anatomy and Proteases—A Step Forward towards Collagen-Rich Tissue Valorisation

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’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’ 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 °C. Age and anatomy showed a significant effect; the influence of anatomy becomes most important with age. Each enzyme’s effectiveness toward age and anatomy was not the same. The greatest amount of peptides was released from young bones’ 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

Consequences of oral deficiencies on intestinal bioaccessibility of nutrients in elderly QuaPA, UNH, and DTA Teams

International audienceFood transformation starts during mastication, which combined with salivation, reduces particle size and form swallowable boluses. In elderly, oral functions are modified by changes in muscular force or saliva production, among others, providing an inadequate food fragmentation potentially impacting on oral and gastrointestinal digestions. This work aimed to evaluate the consequences of oral deficiencies on glucose release and protein digestibility of bread. 1. BACKGROUND This work demonstrates the impact of oral deficiencies on nutrients bioaccessibility and stresses the importance of designing foods for elderly

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

International audienceEscherichia 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

Oral impairments decrease the nutrient bioaccessibility of bread in the elderly

International audienceIn 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

The impact of processing and aging on the oxidative potential, molecular structure and dissolution of gelatin.

International audienceGelatin is a biopolymer produced worldwide through its dissolution rate is variable. During the manufacturing process, gelatin is exposed to high temperatures known to be responsible for cross-link formation. Moreover, bleaching agents such as hydrogen peroxide are added to lighten the gelatin, leading to oxidation reactions that form cross-links. Cross-links have been reported in the literature to be formed between amino acids and related to decreased gelatin dissolution. The variability of gelatin dissolution is important since gelatin is used in the pharmaceutical industry to make hard capsules which have to satisfy strict dissolution specifications. The objective of this study was to determine how the oxidative potential of gelatin may explain the variability of its dissolution. Amino acid composition was assessed by HPLC and gelatin chemical composition was studied with HRMAS-NMR. Iron and aldehyde contents were also measured. Cross-links involving aldehyde functions were strongly suspected to be formed with aging, as were desmosine-like and dityrosine cross-links. All these cross-links were formed during oxidation reactions that are also strongly suspected to occur during aging. In addition, the origin of production affects the oxidative potential of gelatins when considering their iron content. The amount of aldehyde functions, which reflects the oxidation state of gelatins, differed as a function of their origin of production. The dissolution rate of gelatins could be linked to their oxidative potential (iron content) and the aldehydic products of lipid oxidation. Interestingly, the causes for differences in dissolution varied as a function of their origin of production

Cooking temperature is a key determinant of in vitro meat protein digestion rate: Investigation of underlying mechanisms

International audienceThe present study aimed to evaluate the digestion rate and nutritional quality of pig muscle proteins in relation to different meat processes (aging, mincing, and cooking). Under our experimental conditions, aging and mincing had little impact on protein digestion. Heat treatments had different temperature-dependent effects on the meat protein digestion rate and degradation potential. At 70 °C, the proteins underwent denaturation that enhanced the speed of pepsin digestion by increasing enzyme accessibility to protein cleavage sites. Above 100 °C, oxidation-related protein aggregation slowed pepsin digestion but improved meat protein overall digestibility. The digestion parameters defined here open new insights on the dynamics governing the in vitro digestion of meat protein. However, the effect of cooking temperature on protein digestion observed in vitro needs to be confirmed in vivo

Chicken meat quality: genetic variability and relationship with growth and muscle characteristics

Abstract Background The qualitative properties of the meat are of major importance for poultry breeding, since meat is now widely consumed as cuts or as processed products. The aim of this study was to evaluate the genetic parameters of several breast meat quality traits and their genetic relationships with muscle characteristics in a heavy commercial line of broilers. Results Significant levels of heritability (averaging 0.3) were obtained for breast meat quality traits such as pH at 15 min post-slaughter, ultimate pH (pHu), color assessed by lightness L*, redness a* and yellowness b*, drip loss, thawing-cooking loss and shear-force. The rate of decrease in pH early post-mortem and the final pH of the meat were shown to be key factors of chicken meat quality. In particular, a decrease in the final pH led to paler, more exudative and tougher breast meat. The level of glycogen stored in breast muscle estimated by the Glycolytic Potential (GP) at slaughter time was shown to be highly heritable (h2 0.43). There was a very strong negative genetic correlation (rg) with ultimate meat pH (rg -0.97), suggesting a common genetic control for GP and pHu. While breast muscle weight was genetically positively correlated with fiber size (rg 0.76), it was negatively correlated with the level of glycogen stored in the muscle (rg -0.58), and as a consequence it was positively correlated with the final pH of the meat (rg 0.84). Conclusion This genetic study confirmed that selection should be useful to improve meat characteristics of meat-type chickens without impairing profitability because no genetic conflict was detected between meat quality and meat quantity. Moreover, the results suggested relevant selection criteria such as ultimate pH, which is strongly related to color, water-holding capacity and texture of the meat in this heavy chicken line.</p