Insight into the mechanism of ultrasound-assisted cold plasma alleviated the allergenicity of peanut protein with improved functional properties

Peanuts are classified as the major allergens worldwide. This study aimed to investigate the effects of ultrasound-assisted cold plasma treatment (UC) on the structure, functionality, safety, and allergenicity of peanut protein (PP). The research findings revealed that compared with untreated PP, UC treatment for 25 min (UC25) could facilitate the transition of α-helix to β-sheet in the secondary structure. At the same time, there was a 77% decrease in the fluorescence intensity of aromatic amino acids and a 32.83-fold increase in hydrophobicity. These structural changes contributed to an increase in the emulsifying and foaming capabilities of PP by 102% and 63%, respectively. In vitro allergenicity results indicated that compared with ultrasound treatment (UL) group, the strong oxidizing property of UC25 could disrupt both native and exposed allergenic epitopes, resulting in a 74% reduction in IgG binding capacity. The results of mouse experiments revealed the ability of UC25 treatment to restore the Th1/Th2 balance by promoting IFN-γ secretion (increased by 2.11-fold) and inhibiting IL-13 secretion (decreased by 46%), further confirming the significant alleviation of allergic symptoms by UC25. This study aimed to provide new insights for the development of novel hypoallergenic peanut products. • Ultrasound and cold plasma were applied for modifications of peanut protein (PP). • Combined treatments induced hydrogen bond rearrangement and exposed hydrophobic groups of PP. • Combined treatments reduced allergenicity, while enhancing emulsifying and foaming capabilities of PP. • Combined treatments restored the Th1/Th2 cellular balance.