Structure and physical stability of plant-based food gel systems: Impact of protein (mung bean, pea, potato, soybean) and fat (coconut, sunflower)

Abstract

Despite their popularity, plant-based food gel systems (GS) sometimes have suboptimal texture compared to animal-based products. Therefore, 4 commercial plant proteins (from mung bean, pea, potato and soybean) and 2 commercial plant fats (sunflower oil and coconut fat) in 2 contents (7.5 wt% and 17.5 wt%) were evaluated towards their contribution to structure and physical stability a lean (LGS, no fat) and an emulsified GS (EGS). Generally, protein source had a larger effect on structure and physical stability than fat source and content. Unheated, GS with soybean protein showed most structure and highest physical stability. Heated till 94 °C, the structure of GS increased drastically, but EGS showed less structure than LGS, attributed to low solid fat contents (SFC), hence low rigidity, of the incorporated oil droplets at 94 °C. Cooled till 5 °C all GS showed an additional increase in structure, for GS with mung bean and pea protein accompanied with an increase in physical stability. Overall, EGS with sunflower oil showed less structure and lower stability than EGS with coconut fat, likely due to their different SFC. At 5 °C, Peak force of GS with potato protein was highest. Across protein sources, EGS displayed a higher Peak force with coconut fat than with sunflower oil, again likely due to different SFC, hence, rigidity of the oil droplets. Physical stability of GS did not vary significantly between protein sources, fat sources nor fat contents, after a freeze-thaw cycle, nor during prolonged cold storage.