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 buf fer, 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 pr oteins. Within the acid soluble fraction, some proteins and polypeptides we re more readily degraded than the others. In the acid insoluble fraction, e xcept for the loss of a 70, 000 Dalton polypeptide no other major changes w ere observed. Changes in protein composition were more rapid at 150C heatin g than at 125C heating. These data suggest that the proteins of the acid so luble fraction are highly sensitive to heating and thus may have a role in flavor volatile production during roasting of the peanut.