Identification of heat sensitive proteins during roasting of peanut seed

Peanut (Arachis hypogaea L) seed were heated at 125C and 150C between 0 to 24 min and the seed proteins were extracted with 0.1 M sodium phosphate buffer, pH 2.5. The soluble and insoluble proteins were analyzed to determine changes in protein and polypeptide composition during heating. Acid soluble proteins were more susceptible to thermal breakdown than acid insoluble proteins. Within the acid soluble fraction, some proteins and polypeptides were more readily degraded than the others. In the acid insoluble fraction, except for the loss of a 70, 000 Dalton polypeptide no other major changes were observed Changes in protein composition were more rapid at 150C heating than at 125C heating. These data suggest that the proteins of the acid soluble fraction are highly sensitive to heating and thus may have a role in flavor volatile production during roasting of the peanut.