Protein source and starter culture shape the sensory, structural, and metabolic profiles of plant-based yoghurt analogues

Faba bean ( Vicia faba L.) and oat ( Avena sativa L.) represent promising sources for ingredients for plant-based dairy alternatives, yet their functional performance and impact on sensory and physicochemical properties remain underexplored. This study developed plant-based yoghurt analogues (PBYAs) using faba bean flour and oat protein concentrate, assessing how raw material composition and lactic acid bacteria (LAB) starter cultures influence product characteristics. PBYAs were produced by enzymatic starch hydrolysis of faba bean and oat formulations to generate fermentable sugars and limit excessive starch gelation. After fermentation with selected LAB cultures, a low pH was reached and a yoghurt-like texture and acidic flavour was achieved. PBYAs were examined for their properties and appraised sensorially by a quantitative descriptive analysis, while metabolomic profiles were determined by nuclear magnetic resonance (NMR) spectroscopy. The inclusion of oat protein concentrate significantly altered the product matrix, leading to reduced viscosity, lower whiteness index, and a grainier texture compared to pure faba bean PBYAs. While raw material choice was the primary driver for sensory characteristics, the choice of bacterial culture was the primary driver of the differences in metabolomic profile. The results demonstrate that faba bean and oat can be used to produce PBYAs with desirable yoghurt-like properties. However, the functional limitations of oat protein and its impact on sensory characteristics remain key challenges. Future research should focus on improving structural properties and evaluating consumer acceptance of faba bean- and oat based PBYA.