Rheological and textural properties of heat-induced gels from pulse protein isolates: Lentil, mungbean and yellow pea

Abstract

The molecular structure and conformation of the plant-based proteins dominate their gelation behaviour. These aspects have been mostly overlooked for underutilised pulse proteins such as lentils and mungbean that differ structurally with soy and pea proteins. Rheological and textural properties of heat-induced gels of lentils (LPIs) (green, red and black lentils), mungbean (MBPI) and yellow pea (YPPI) were compared with commercial soy (CSPI) and pea (CPPI) protein isolates. On investigation of the dynamic rheological parameters, the critical protein concentration (CPC) of MBPI was the lowest (14% w/v) followed by LPIs (18% w/v) and YPPI (22% w/v). Also, vicilin-rich MBPI showed a lower gelation temperature (Tgel 77 °C) and developed stronger gels compared to LPIs and YPPI. On the other hand, commercial isolates with larger particle size, water holding capacity and denatured state showed lower CPC (CPPI, 14% w/v) than their folded and more soluble counterparts (YPPI 22% w/v). Hence, the study of thermo-rheological properties of pulse proteins with distinct molecular and conformation characteristics has yielded a structure-gelation paradigm. These findings support the development of plant protein-gelled products not limited to meat and dairy analogues.