2014/01/01 by Didier Dupont, Dupont, Didier, Olivia Ménard +5
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #Protein Hydrolysis and Bioactive Peptides #Muscle metabolism and nutrition #Proteins in Food Systems
paper · doi:10.17180/tvsa-ks24
Little is known about the effect of the structure on the nutritional properties of food. The objective of this work was to determine if dairy gels of identical composition but obtained through different gelation process exhibited different protein kinetics of digestion and amino acid release in plasma. Using a heattreated milk (90°C/10 min), an acid and a rennet gel were manufactured. These two gels exhibited similar microstructure (mean pore diameter of 0.8μm) and rheological properties (identical loss factor tan δ). Multi-canulated (duodenum and jejunum) adult mini-pigs bearing blood catheters were fed these matrices. Milk protein kinetics of digestion were directly related to the time of residence of the matrices in the stomach that was driven itself by the gel structure. Acid gels showed a lower time of residence in the stomach than the rennet one. Number of peptides identified in the intestinal lumen throughout the 7h of digestion was 3 times higher for the acid gel (4349 vs 1443). The acid gel caused a fast and sharp increase of essential amino acids in the plasma. Rennet gel induced more satiety than acid ones. Supplementary data obtained in vitro and in silico showed a strong casein particle aggregation in the stomach for rennet gel leading to a higher time of residence and a contraction of the protein network followed by an expulsion of whey (syneresis) causing a rapid gastric emptying of the whey proteins.