Dynamic rheological properties of peanut protein isolate and aggregation suspension and acid-induced gel

Abstract

The dynamic rheological properties of peanut protein isolate (PPI) aggregation suspension and acid-induced PPI gels were studied. The strain sweep, frequency sweep, steady state shear flow test, and the time sweep were carried out on PPI aggregation suspension (23%–27%) and acid-induced PPI gel (14%–22%) separately. The frequency sweep curve fits the Power Law model very well, and the G′ of PPI aggregation suspensions and PPI gel were shown a greatly frequency dependence within the frequency range of 0.1Hz to 10Hz. The steady-state shear curve indicated well matched with the Carreau and Power Law model, which figured a shear-thinning behavior of the concentrations, and the constants estimated empirically showed shear rate dependence. The acid-induced PPI gel showed a Type I behavior (thinning of the strain), which the chains of acid-induced PPI consisted of a protein entanglement in the linear viscoelastic region (LVR), where the modulus is constant. With the strain rising, the protein chains disentangle and then correspond with the flow region. It was easily broken down and protein gel molecules have small opportunity to re-establish the entanglement.