Oyster mushroom mycelium lifts okara protein to 30% in an NTU Singapore study

What Happened

Nanyang Technological University researchers grew oyster mushroom mycelium on okara, the soybean-pulp by-product, by solid-state fermentation. Protein rose to 27.7–30.2% by dry weight, glucose rose 2.8 to 6.4 times and umami compounds rose several-fold. Sourness fell, but some samples turned more bitter and dry. The work was published in Food Chemistry: X.

Why It Matters

Okara is produced in large volumes by tofu and soy-milk plants, but its fibre content, short shelf life and weak flavour have limited its use. Upgrading it with a low-input fungal step could turn a waste stream into an ingredient. The researchers say energy use, food safety, storage stability, sensory testing and economics still have to be assessed before commercialization.

Tofu's leftover pulp climbs to 30% protein, with a bitter aftertaste to solve.

FET's Takeaway

The 11-day incubation to full coverage on fresh okara is the commercial sticking point. Residence time drives fermenter or tray capacity and therefore cost per kilo. The rise in bitterness and dryness also means this is more likely to go into blended or savoury applications than be used as a neutral protein.