Small Peptides Hydrolyzed from Pea Protein and Their Maillard Reaction Products as Taste Modifiers: Saltiness, Umami, and Kokumi Enhancement

Pea protein was used to prepare the Maillard reaction products (MRPs) through enzymatic hydrolysis and further thermal reaction with reducing sugar. A pronounced saltiness improvement in NaCl solution was observed by the addition of hydrolysates and their MRPs. Low-molecular-weight pea peptides had the strongest effect of saltiness and umami enhancement. The saltiness-enhancing effect of MRPs derived from hexoses was higher than that from pentoses. Molecular weight distribution and amino acid content of MRPs prepared under different time revealed that the hydrolysis of peptides and the initial Maillard reaction of hydrolysis products were dominant at 1 h of thermal reaction. With the extension of heating time, further reaction of small tasty peptides led to a decrease in the saltiness enhancement. The kokumi attribute was mainly contributed by the MRPs of small peptides. When the dosage of MRPs was 0.7% coupled with 0.4% NaCl, the saltiness of the solution was higher than that of the control (0.5% NaCl), which meant that the saltiness was not weakened even when the NaCl concentration was reduced by 20%. The results of the electronic tongue analysis were consistent with that of the sensory evaluation.