Comparison of gelatin and low-molecular weight gelatin hydrolysate ingestion on hydroxyproline (Hyp), Pro-Hyp and Hyp-Gly concentrations in human blood

Iwasaki Y, Nakatogawa M, Shimizu A, Sato Y, Shigemura Y · Food Chemistry

Intact gelatin raised plasma Pro-Hyp to 15.5 nmol/mL at 2 h and Hyp-Gly to 2.3 nmol/mL at 1 h. The low-MW hydrolysate did better on both, but ordinary gelatin hydrolysate did NOT significantly beat plain gelatin on Hyp-Gly peak or AUC. The authors conclude gelatin is useful as a functional food as effectively as hydrolysate — which matters because home-cooked stock yields gelatin, not peptides.

Population

Healthy human volunteers, crossover

Intervention

Intact gelatin, gelatin hydrolysate, or low-molecular-weight gelatin hydrolysate

Comparator

The three preparations against each other

Limitations

Very small (n=9) acute pharmacokinetic study with surrogate endpoints only; free hydroxyproline absorption WAS significantly lower from gelatin than from either hydrolysate, so the preparations are not fully equivalent.