Transglutaminase Mediated Cross-linking of Peanut Protein and Casein Pretreated by Dual Frequency Ultrasound and Its Functional Properties
The enzymatic cross-linking of peanut protein and casein mediated by transglutaminase (TG)using dual frequency ultrasound pretreatment were investigated in the present study.Firstly,the cross-linking parame-ters were optimized by single factor experiments and orthogonal experiments.Further,the effects of non-enzymatic cross-linking,conventional enzymatic cross-linking and ultrasonic-assisted enzymatic cross-linking on the functional characteristics,secondary-microstructures of the protein were compared.The results indicated that the optimal ultrasound parameters were ultrasonic treatment time of 15 min,ultrasonic power density of 40 W/L,dual-frequency ultrasonic working time ratio 50 s:10 s (25 kHz:40 kHz),and ultrasonic temperature of 50 ℃ at a certain crosslinking condition (peanut protein isolates∶casein of 4∶3 (g:g),pH of 6.0,temperature of 50 ℃,enzyme dosage of 1％ and time of 2 h).Compared to the non-enzymatic crosslinking and the common enzymatic crosslinking,the degree of crosslinking (DC)increased by 75.41％ and 39.70％,respectively.The oil absorp-tion,foaming stability,emulsifying stability and water holding capacity (WHC)of gels were 7.17％,43.99％,15.10％ and 9.93％ higher than those of the non-enzymatic crosslinking,respectively;however,the WHC,foa-ming capacity and emulsifying capacity decreased by 7.83％,40.38％ and 5.72％,respectively;whereas the solubility decreased at pH 3.0-12.0 to different degrees.The secondary structure analysis results indicated that the β-sheet decreased by 4.34％ while theβ-Turn increased by 5.33％ in comparison with the non-enzymat-ic crosslinking.
dual frequency ultrasoundproteinenzymatic crosslinkingfunctional characteristicsstructural properties
万方数据
维普
