SALT-SUST: Novel salt replacement strategy using an underexploited soy industry co-product

The SALT-SUST project is a collaboration between Queen Margaret University and several food companies (Macphie, Bells, Baxters, Peacock Salt, Shoda Sauces and Tai Hua). The project proposes a game-changing solution to significantly accelerate the reduction of salt consumption in the UK and its dramatic impact on health and the NHS. The strategy is based on the development of soy sauce cake (SSC), an underexploited by-product from the soy sauce industry, into a novel salt substitute.

Meeting Public Health England's Salt Reduction Targets for 2024 (GW-1435 publication) poses a number of challenges to the industry, as in addition to saltiness, salt is key to overall flavour, colour, texture, shelf-life and is inexpensive. There is currently no salt reduction strategy that meets all these challenges due to cost, acceptability (flavour loss, off-flavours, clean label issues) or health concerns.

A preliminary study carried out at QMU showed that SSC has the potential to meet these challenges. It is a natural material (solid residue obtained following mechanical pressing of fermented soybeans), its processing is cost-effective and it contains high levels of umami compounds providing flavour-enhancing properties which counterbalance flavour loss at reduced-salt levels.

The project aims to develop novel sustainable and cost-effective salt-reducing ingredient (Shoda Sauces) and blend (Peacock Salt), as well as competitive salt-reduced products meeting the 2024 salt level targets, including bakery mixes and savoury sauces for the catering and food service industries (Macphie), pastry and meat pies (Bells) and soups (Baxters).

This early-stage project will assess the feasibility of the strategy based on technical, sensory, sustainability, cost, legislative and logistical aspects. The reproducibility of the SSC material across the industry will be assessed by comparing SSC ingredients from Shoda Sauces (UK) and Tai Hua (Singapore).

The strategy is targeting commonly eaten products to ensure the health benefits are widely accessible and at affordable prices due to the cost-effectiveness of SSC. Such development will reduce the financial burden of (reduced high blood pressure and cardiovascular disease on the NHS.

The SALT-SUST project also proposes a game-changing solution to the dramatic environmental impact of SSC disposal as industrial waste. 110,000 tonnes pa is produced worldwide but only a fraction is used as low-value stream (animal feed, fertiliser) due to lack of systematic upcycling process.

The project will benefit the industry partners and will in turn create opportunities for wider industry to adopt the strategy, benefit economically and create jobs.