Improved stability of sesame paste by peanut protein-flaxseed gum conjugation

The oil-water separation phenomenon in sesame paste poses a challenge for the storage of sauce products. In this study, soy protein isolate (SPI), peanut protein isolate (PPI) and flaxseed gum (FG) conjugates were prepared to stabilize the solid-liquid phases of sesame paste. The results indicated that the highest degree of grafting (25.07%) was observed in a ratio of PPI:FG=4:1 (PF2). The interaction between proteins and FG generated the extension of the protein molecule and increased structural disorder. PPI-FG conjugates exhibited the lower surface hydrophobicity and higher thermal stability. The addition of 4% PF2 to sesame paste led to a reduction of 5.06% oil separation rate and showed higher storage modulus (G'), loss modulus (G"), apparent viscosity, and hardness. A stable and continuous three-dimensional network was created to physically entrap the oil, resulting in a more uniform distribution of oil droplets and a reduced particle interaction of sesame paste.