Effect of phenolic compound removal on rheological, thermal and physico-chemical properties of soybean and flaxseed proteins

This study aimed to investigate the effect of removal of phenolics on physico-chemical properties of protein isolates obtained from flaxseed and soybean. Proteins were isolated (I) from full-fat (F) and defatted (D) soybean (s) and flaxseed (f) using isoelectric precipitation. Free and bound phenolics were removed from the protein isolates. Thermal and gelation properties of protein isolates before and after removal of phenolics were investigated. Protein isolates from defatted soybean after removal of free and bound phenolics were showed a decrease in thermal stability of glycinin. For protein isolate from full-fat soybean, the results showed the removal of free phenolics increase thermal stability of glycinin with increase water holding capacity (WHC) and produce more viscous and less elastic gels as compared to protein isolate after removal of bound phenolics. Removal of free and bound phenolics from flaxseed protein isolates decrease thermal stability, WHC and viscoelastic properties as compared to protein isolate after removal of free phenolics.