Study on the interaction of sweet protein (thaumatin) with key aroma compounds in passion fruit juice using electronic nose, ultraviolet spectrum, thermodynamics, and molecular docking

As a high-intensity sweetener and flavor enhancer, thaumatin has received a lot of attention from the industry with the increasing demand for sugar reduction. Also as a protein, it can interact with volatiles to influence the overall consumer perception of the product. This work was the first to explore the interaction between sweet protein and aroma. Volatile substances were analyzed using SPME and SBSE. 24 volatiles were identified as key aroma compounds in passion fruit juice by AEDA in combination with OAV. The electronic nose result that there were differences in aroma between the juices after adding different concentrations of thaumatin. In addition, the adsorption capacity experiments showed that thaumatin had an adsorption effect on furfural, dihydro-beta-ionone, and geraniol, and release effect on ethyl hexanoate and limonene. Ultraviolet spectrum analysis showed that furfural, dihydro-beta-ionone, and geraniol can interact with thaumatin. The thermodynamic and molecular docking results further indicated that these interactions were mainly guided by hydrophobic, hydrogen bonds, and electrostatic interactions.