Kokumi Substance Obtained from Vegetable Protein Hydrolysates through Salt-Free Processing

Area of Science:

• Food Science and Technology
• Sensory Science
• Molecular Gastronomy

Background:

• Enzymatic hydrolyzed vegetable protein (EHVP) is known to possess flavor-enhancing properties.
• The specific compounds responsible for the 'kokumi' taste sensation, characterized by mouthfulness and richness, are not fully understood.
• Understanding kokumi substances can lead to novel flavor development in food products.

Purpose of the Study:

• To isolate and characterize the kokumi substance present in EHVP.
• To evaluate the sensory impact of the isolated kokumi substance on taste perception, specifically mouthfulness and astringency.
• To determine the structural components responsible for the kokumi activity.

Main Methods:

• Isolation of kokumi substance from EHVP using ultrafiltration and chromatography.
• Sensory evaluation of EHVP and its fractions using beef extract solutions.
• Chemical characterization of the isolated kokumi substance and its analogs.

Main Results:

• EHVP significantly enhanced mouthfulness and astringency in beef extract solutions.
• The kokumi substance was identified as a glycopeptide composed of a tetrapeptide and a seven-sugar N-linked glycan.
• The glycopeptide exhibited an exceptionally low taste threshold (1 ng/g) for enhancing mouthfeel and astringency in the presence of other taste compounds.

Conclusions:

• The peptide portion of the glycopeptide is the primary structure responsible for the kokumi effect.
• The glycan moiety enhances the kokumi activity of the peptide component.
• This research identifies a potent, low-threshold kokumi substance with potential applications in the food industry for flavor enhancement.