Leveraging Neurospora crassa in Co-culture fermentations: Modulating the taste, aroma, and enhancing fatty aroma profiles in fermented soybean products

Fermented soybean products offer nutritional benefits and complex flavour profiles shaped by microbial interactions. This study investigates the potential of Neurospora crassa (NC) in co-culture fermentations to enhance the sensory qualities of soybean-based products. After 72 hours, significant growth was observed across all strains, with peak times varying by species. Moulds peaked at 72h, yeasts at 48h in monoculture but extended to 72h in co-culture, while lactic acid bacteria (LAB) strains peaked at 48h but showed enhanced growth when paired with NC. Sugar analysis revealed significant sucrose reductions in NC, Rhizopus oryzae (RO), and Kluyveromyces marxianus (KM) monocultures due to invertase activity, with further depletion in NC co-cultures. Free amino acid (FAA) levels were highest in mould-fermented samples, especially RONC, due to strong proteolysis. E-tongue analysis showed distinct taste profiles, with RO, RONC, and NC- Lacticaseibacillus casei (LC) samples exhibiting enhanced umami intensity. Fatty acid analysis revealed elevated levels in NC, RO, and RONC, linked to de novo synthesis. Volatile analysis indicated reduced beany notes and the emergence of ‘meaty,’ ‘savoury,’ and ‘fatty’ aromas. Overall, NC-based co-cultures improve flavour, umami, and nutritional quality, supporting their use in developing palatable, protein-rich, plant-based foods. • Neurospora crassa cocultures reduce off-flavours in fermented soybeans • N. crassa–Rhizopus oryzae coculture boosts umami and fatty aromas • N. crassa–Lactiplantibacillus plantarum raises acetoin and ethyl acetate • Cocultures generate complex and balanced aroma in soy-based products • N. crassa provides a novel route for flavour-optimized fermentation