Scientific gastronomy: On the mechanism by which garlic juice and allicin (thio-2-propene-1-sulfinic acid S-allyl ester) stabilize meringues

Garlic juice (GJ) contains allicin, a bioactive that stabilizes egg white (EW) foams without potassium bitartrate (cream-of-tartar), meeting the aim to identify clean-label ingredients that alter foam characteristics. 0.001 wt% allicin in EWs forms stiff foams with the highest overrun (∼800 %) and delayed drainage (60 min). Whipping EW with GJ or allicin changes the disulfide-bridge conformation of the EW foam from 56, 44, and 0% gauche-gauche-gauche (SSg-g-g), trans-gauche-trans (SSt-g-t), and trans-gauche-gauche (SSt-g-g) to 11, 52, and 37%. Raman microspectrometry (RM) found higher relative percentages of SSg–g–g disulfide bonds coincide with rapid foam collapse, while the tyrosine I850/I830 band ratios, a measure of tyrosine surface exposure, remained constant. These changes in spectra illustrate that polypeptide chain displacement and protein unfolding are essential in stabilizing bubble interfaces. Few clean-label functional compounds alter foam stability and functionality, and compounds such as allicin could lead to entirely new culinary techniques and dishes.