Digestion study of proteins from cooked meat using an enzymatic microreactor

International audienceA semi automatic flow procedure with photometric detection was developed for the study of meat protein digestion. This system comprised two independent flow pathways, gathered by two compartments. The gastric compartment was simulated by an ultrafiltration cell fitted with a 10 KDa cut off membrane and the intestinal compartment was simulated by a 1 KDa cut off dialysis membrane. The pathways were filled with solutions simulating digestive conditions. The proposed system was employed in digestion studies of whole protein extracts from raw and cooked (100°C) meat. A mathematical modelling for the determination of the digestive kinetic constants was established. The results show that meat cooking leads to an important decrease of protein digestibility by proteases of the digestive tract

Effect of I199V polymorphism on prkag3 gene on carcass and meat quality traits in slovenian commercial pigs

International audienceThe effect of I199V polymorphism at the PRKAG3 gene on carcass and meat quality of commercial pigs was studied independently from PRKAG3 200Q or RYR1 "n" allele, known to decrease meat quality, i.e., animals were genotyped for RYR1 R615C, PRKAG3 I199V and R200Q substitutions, and only pigs without 200Q and "n" were retained for the analysis of carcass and meat quality traits (n = 274). Genotype frequencies were 12.0, 57.7 and 30.3% for I/I, I/V and V/V, respectively. The I199V polymorphism affected significantly fat thickness and drip loss and tended to affect ultimate pH. Interestingly, I/V were the fattest and significantly different from V/V, with I/I pigs being intermediate. The ultimate pH of I/I was higher than the one of I/V or V/V pigs. Regarding drip loss, significant difference was detected between I/I and V/V pigs. The heterozygous I/V pigs were intermediate with differences to I/I or V/V tending toward significance

Electronarcose des volailles : quels paramètres techniques ?

National audienc

Technological and sensory pork quality in relation to muscle and drip loss protein profiles

International audienceFifteen meat samples collected from pigs (Neckar hybrid line) were selected from 75 animals on the basis of their technological quality traits, and the samples were classified as normal, PSE, and acid meat. Sensory analysis was performed on the three meat categories. Total meat protein and drip loss protein were analyzed by electrophoresis (SDS-PAGE), mass spectrometry, and image analysis. From a sensory point of view, PSE meat was characterized by lower color intensity, and acid meat was characterized by the lowest score of juiciness. Certain soluble proteins derived from the drip loss were associated with meat quality, especially phosphoglucomutase and the B chain of hemoglobin in the case of PSE and acid meat. Low quantities of myofibrillar proteins (myosin LC1, troponin T (TnT) and troponin C (TnC)) in meat with high glycogen levels and low pH levels resulted in a higher rate of proteolysis of myofibrillar proteins due to higher enzymatic proteolysis activity in the meat. The results of this study showed that the TnC/TnI ratio may be a pertinent marker of postmortem muscle metabolism and that this ratio is related to textural properties

Effect of modified atmosphere packaging on color stability and on microbiology of turkey breast meat

International audienc

New quality assessment techniques

International audienc

Effect of modified atmosphere packaging on color stability and on microbiology of turkey breast meat

International audienc

Dry-cured ham Kraski prsut seasoning losses as affected by PRKAG3 and CAST polymorphisms

International audienceAssociation between polymorphisms on PRKAG3 (Ile199Val) and CAST (Lys249Arg and Ser638Arg) genes and dry ham seasoning losses was studied. A total of 724 green hams (same pig crossbreed, same pig producer) were selected, genotyped (PCR-RFLP) and processed according to the rules of consortium for dry-cured ham Kraski prsut. Weight losses after each processing phase were recorded. We observed significant effect of interaction between gene polymorphism and dry ham producer on seasoning losses, indicating that the effect of studied genes differ in relation to manufacturing practice or product type, despite narrow consortium constraints. The analysis was thus made separately for each producer; in case of producer B, PRKAG3 affected salting, resting and overall losses (Val/Val higher than Ile/Ile or Ile/Val) but in case of producer A, the effect of PRKAG3 was significant only for salting losses (Ile/Val lower than Ile/Ile or Val/Val). Effects of CAST polymorphisms were significant only in case of producer A; CAST249 Arg/Arg hams showed the highest first salting, drying, and overall seasoning losses, whereas CAST638 Arg/Arg hams had the highest drying, ripening, and overall seasoning losses. In conclusion, PRKAG3 and CAST polymorphisms were associated with seasoning losses, important from economic viewpoint, but also for salt intake and product quality

Quantification of peptides released during in vitro digestion of cooked meat

International audienceWe aimed to identify and quantify the peptides generated during in vitro digestion of cooked meat by liquid chromatography coupled with high resolution mass spectrometer. A total of 940 non-redundant peptides in the gastric compartment and 989 non-redundant peptides in the intestinal compartment were quantified and identified. Among the 71 different proteins identified, 43 meat proteins were found in the two digestive compartments, 20 proteins were specific to the gastric compartment and 8 proteins to the intestinal compartment. In terms of estimation, the proteins involved in muscle contraction and structure were preferentially enzymatically hydrolyzed in the small intestine. The effect of cooking provided different but less clear patterns of digestion. To the best of our knowledge, this constitutes the highest number of peptides identified in beef meat digests and provides a comprehensive database for meat protein digestion associated with cooking conditions. Such quantitative and qualitative differences may have important nutritional consequences

Modeling of pepsin digestibility of myofibrillar proteins and of variations due to heating

International audienceDigestibility of myofibrillar proteins by pepsin was determined by in vitro trials and mathematical modelling. A primary model was developed to predict in vitro digestion kinetics, and a secondary model based on the mechanisms of protein denaturation was then added to take into account the effect of meat heating. Model predictions agreed with measurements in the pH and pepsin concentration ranges 1.8–3.8 and 6–50 U mg 1 respectively. The utility of the model is illustrated by a simple example where meat is assumed to be heated homogeneously, and myofibrillar proteins to be directly in contact with pepsin. The combined effects of heating time, temperature, enzyme concentration and pH modified the digestibility value, which also depends on residence time in the stomach