Amount of Collagen in the Meat Contained in Japanese Daily Dishes and the Collagen Peptide Content in Human Blood after Ingestion of Cooked Fish Meat

Objectives of the present study were to evaluate amounts of collagen in Japanese daily dishes and contents of food-derived collagen peptides in human blood. The meat in one serving of most Japanese daily dishes contains 0.2–2.5 g of collagen, except for beef tendon, eel with skin, and skinned shark tail (7.6–13.3 g). After ingestion of cooked shark meat, nine collagen di- and tripeptides were detected in plasma and the area under the curve of most peptides, except for Hyp-Gly and Pro-Hyp-Gly, was ∼30% of that after ingestion of collagen hydrolysate containing an equivalent amount of collagen. Likewise, only ∼30% of the total collagen in the meat was liberated into solution by pepsin and pancreatin digestion. Thus, ingestion of collagen-rich meat increases the collagen peptides in blood, which depends on not only the collagen content in the meat but also the susceptibility of the collagen/gelatin to digestive endoproteinases.