Enhancing saltiness perception by chemosensory interaction: an fMRI study

Area of Science:

• Neuroscience
• Sensory Science
• Food Science

Background:

• Flavor perception and reward are modulated by interactions between taste and odor stimuli.
• Understanding these interactions is crucial for developing healthier food options, like reduced-sodium products.
• Neuroimaging techniques offer insights into the brain regions involved in processing complex sensory information.

Purpose of the Study:

• To investigate how cheddar cheese odor and monosodium glutamate (MSG) influence the perception and preference of saltiness in sodium chloride (NaCl) solutions.
• To identify the brain regions activated by the interaction of odor and taste stimuli using functional magnetic resonance imaging (fMRI).

Main Methods:

• A sensory experiment was conducted to evaluate the effects of cheddar cheese odor and MSG on NaCl solutions.
• fMRI was employed to study brain activity in response to various odor-taste combinations.
• Participants rated the saltiness and preference of NaCl solutions under different conditions.

Main Results:

• Sensory tests revealed that the combination of MSG and cheddar cheese odor significantly enhanced the saltiness and preference of NaCl solutions.
• fMRI data indicated that increased saltiness perception activated the rolandic operculum.
• Enhanced preference correlated with activation in the rectus, medial orbitofrontal cortex, and substantia nigra.

Conclusions:

• Odor-taste interactions, specifically involving cheddar cheese odor and MSG, can effectively enhance saltiness perception and preference.
• The study identified key brain areas, including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), temporal pole, and amygdala, involved in processing these combined sensory inputs.
• Findings suggest potential applications in food product development for creating palatable low-salt alternatives.