Foam-templating strategy for structuring edible fat analogs using fractionated black bean protein and xanthan gum

Abstract: 
As more consumers are adopting healthier plant-based foods and recognizing the large environmental costs of animal production, there has been a growing need for sustainable plant-based fat mimetics that can effectively simulate animal fats and replace commonly used highly saturated tropical oils in alternative protein and dairy products.  Black beans (Phaseolus vulgaris) are affordable, protein-rich crops that are relatively underutilized in the alternative foods space.  In this study, bean protein fractions (concentrate and isolate) obtained using a solvent-free extraction method were prepared into freeze-dried foams in combination with a stabilizing hydrocolloid (xanthan gum) under optimized pH conditions.  The freeze-dried foams were used as templates to absorb and structure canola oil into semi-solid oleogels.  Properties of the foam templates and their oleogels were dependent on protein composition, with bean protein concentrate forming slightly denser foams with lower oil capacity and retention compared to bean isolate.  Oleogels prepared with bean isolate displayed significantly lower firmness, cohesiveness, springiness, and gumminess than bean concentrate oleogels by texture analysis, likely due to the less compact, more brittle structure of their foam templates.  Rheological tests demonstrated that both isolate and concentrate oleogels maintained elastic-dominated viscoelastic behavior with no melting-like transition when heated up to 100°C, and recovered their structure after cooling back to 20°C.  This work demonstrates the potential for using black bean protein-polysaccharide systems to structure vegetable oil-based fat analogs, as well as tailoring their composition to improve functionality for different food applications, to promote the development of more sustainable, healthy plant-based food products.