Stinky tofu might smell like it belongs in a back alley, but to fans, its funk is pure flavour gold. Love it or hate it, its intense aroma and taste highlight how microbial fermentation can sculpt unique sensory experiences. Still, what if the same process behind stinky tofu could be tuned to create soy-based products that smell cleaner, taste richer and still deliver the same umami goodness with wider appeal?
To turn bland into bold and funky into refined, researchers at the A*STAR Singapore Institute of Food and Biotechnology Innovation (A*STAR SIFBI) have uncovered how some novel microbial strains can transform the aroma and taste of fermented soybean products.
“We want to create new sensory experiences that make these plant-based foods a flavourful, everyday choice for people, regardless of their dietary preferences,” said Yvonne Chow, an A*STAR SIFBI Principal Scientist and study leader.
The team—which included A*STAR SIFBI Senior Research Officer Xin Hui Chin, former Research Fellow Hosam Elhalis and Senior Scientist Aaron Thong—worked with Shao Quan Liu from the National University of Singapore to examine several bacterial and fungal strains not typically associated with soybeans, but well-known for producing savoury and umami notes in meats and cheeses.
“The idea was to adapt flavour chemistry from traditionally-fermented animal products to plants, using microbial strains already recognised as safe for human consumption,” said Chin.
The team found that a carefully-controlled environment was needed as some of the most promising flavour-producing candidates required highly specific conditions, while naturally-present Bacillusmicrobes could disrupt fermentation and their desired flavour outcomes.
Through aroma analysis conducted via an A*STAR SIFBI analytical platform, the team also found that under the right conditions, certain strains significantly enhanced the soy base’s depth of flavour. For example, Rhizopus oryzae drove an eight-fold increase in free amino acids, correlating with a marked boost in umami intensity.
“The strain that stood out most to us, both scientifically and sensorially, was Neurospora crassa,” said Chin, highlighting a mould used in the traditional production of oncom: a fermented peanut or soy waste staple of Javanese cuisine. “We found that its ability to produce methionine—a sulphur-containing amino acid linked to ’meaty’ and ’broth-like’ notes—added a depth and umami complexity often missing in plant-based products.”
Chin added that text here Penicillium mould species such as P. nalgiovense and P. camemberti—familiar from cured meats and cheeses—also adapted surprisingly well to a plant-based matrix, forming blooms typically seen on animal-based products. These strains generated high lipase activity levels which added to more complex aromas and enhanced mouthfeel.
Encouraged by these outcomes, the team have since experimented with co-cultures and uncovered new flavour combinations that led to a recent patent. They are also pursuing advances in bioprocess engineering and environmental control to scale up their promising discoveries to a full production line, aiming to tackle consistency issues in microbial performance.
“Ultimately, our work shows that plant-based substrates, when paired with the right microorganisms, can become a rich canvas for flavour innovation,” Chin said.
The A*STAR-affiliated researchers contributing to this research are from the A*STAR Singapore Institute of Food and Biotechnology Innovation (A*STAR SIFBI).
