Drivers of the In-Mouth Interaction between Lupin Protein Isolate and Selected Aroma Compounds: A Proton Transfer...

Area of Science:

• Food Science
• Sensory Science
• Analytical Chemistry

Background:

• Plant proteins often have undesirable off-notes, requiring aroma addition to improve palatability.
• Previous *in vitro* studies indicated that proteins can bind aroma compounds, limiting their release and perception.

Purpose of the Study:

• To investigate *in vivo* interactions between plant proteins and aroma compounds within the human mouth.
• To understand how these interactions influence the release and sensory perception of key aroma molecules.

Main Methods:

• Utilized *in vivo* proton transfer reaction-time-of-flight-mass spectrometry (PTR-ToF-MS) to measure aroma release in the nose space.
• Employed dynamic sensory evaluation (time intensity) to assess the perceived intensity of "green" attributes and specific aroma compounds (hexanal, nonanal, 2-nonanone).
• Investigated the effect of protein addition and structural variations in aroma compounds on their release and perception.

Main Results:

• Enlarging aldehyde chains or relocating the keto group in aroma compounds significantly reduced their maximum perceived intensity.
• Protein addition markedly decreased the maximum perceived intensity of tested aroma compounds, confirming protein-aroma interactions.
• Sensory evaluation showed lower perceived intensity with protein addition, and aroma lingering correlated with compound volatility and hydrophobicity.

Conclusions:

• Protein-aroma interactions significantly impact the release and perception of aroma compounds in a food matrix.
• Combining PTR-ToF-MS and time intensity analysis provides valuable insights into in-mouth food behavior.
• Understanding these interactions is crucial for designing palatable plant-based food products with customized flavor profiles.