Kokumi Taste Active Peptides Modulate Salt and Umami Taste.

Area of Science:

• Food Science
• Sensory Science
• Neuroscience

Background:

• Kokumi taste substances, like γ-glutamyl and Maillard peptides, are known to modulate salt and umami sensations.
• The precise mechanisms underlying kokumi peptide action on taste perception remain largely unelucidated.

Purpose of the Study:

• To investigate the effects of peptide fractions from mature (FIIm) and immature (FIIim) Ganjang on salt and umami taste responses.
• To delineate the mechanism of action for kokumi taste substances on taste nerve responses in rodents and taste perception in humans.

Main Methods:

• Isolation of peptide fractions (500-10,000 Da) from mature and immature Ganjang.
• Electrophysiological recordings of rat chorda tympani (CT) nerve responses to lingual stimulation with NaCl and glutamate.
• Human sensory panel evaluation of taste intensity with varying concentrations of peptide fractions.

Main Results:

• Mature Ganjang peptide fraction (FIIm) exhibited a biphasic effect on rat CT responses to NaCl and benzamil (a Na+ channel blocker).
• FIIm synergistically enhanced NaCl-induced CT responses with elevated temperature and significantly increased salt taste intensity in humans.
• FIIm at a higher concentration enhanced glutamate-induced CT responses in rats and umami taste in humans.

Conclusions:

• FIIm modulates amiloride-insensitive salt taste at specific concentrations in rodents and humans.
• FIIm enhances umami taste perception in humans and glutamate response in rodents.
• These findings suggest distinct concentration-dependent mechanisms for FIIm's modulation of salt and umami tastes.