Rheological Properties of Mixed Gel Based on Lepidium perfoliatum seed gum and Lathyrus sativa protein isolate

In this research, the gelation and interaction between Lepidium perfoliatum seed gum (LPSG) and Lathyrus sativa protein isolate (LSPI) were determined using dynamic rheology. Sequence of experimental sweeps of time-temperature, frequency, and strain were applied for LSPI-LPSG mixtures in the ratio of 20:1, 10:1, 5:1, 2:1 & 1:2. Rheological behavior of protein isolate was found to be different from that of LPSG and gelling point was raised during the heating period. By increasing LSPI concentration, storage and loss moduli were increased and gel point was determined at about 80 °C, which was dependent of concentration and occurred during cooling period. Upon heating-cooling process, mixed gels showed a biphasic profile: the first phase, characterized by a sharp increase in the storage modulus where protein gelling occurred and the second phase showing an increase in the storage modulus, corresponded to the build-up of a LPSG network. The results of the strain sweep test for mixing gels at the end of the temperature sweep test supported the above hypothesis. In addition, FTIR of mixed gel showed a bicontinuous network in which LPSG dispersed in LSPI continuous phase.