Most would not associate soft off-white blocks of tofu with alcohol, but a research team from NUS Science has done exactly that. They have developed the world’s first tofu whey alcoholic beverage which also contains antioxidants that are beneficial for health. The production takes a zero-waste approach, creating a new beverage from a product otherwise discarded, and generating no waste in the process.
Tofu is popular in Asian cuisines, and is produced by coagulating freshly boiled soy milk, cooling it and pressing it into blocks with various levels of firmness. Tofu whey is a by-product from the pressing process and is usually discarded. Left untreated, the protein and soluble sugars in the disposed tofu whey can contribute to oxygen depletion in waterways.
Associate Professor Liu Shao Quan and his PhD student Chua Jian Yong, both from the Faculty’s Food Science and Technology Programme, began work on the beverage a year ago.
“The traditional way of manufacturing tofu produces a large amount of whey, which contains high levels of calcium and unique soya nutrients such as isoflavones and prebiotics. Hence, disposing tofu whey is wasteful. Very little research has been done to transform tofu whey into edible food and beverage products,” said Jian Yong.
Under Assoc Prof Liu’s tutelage, Jian Yong took about three months to create the recipe for generating an alcoholic beverage from tofu whey. During the process, Jian Yong also developed an original technique for fermenting tofu whey that utilises tofu whey completely, and enriches the drink with isoflavones, which are naturally occurring antioxidants.
“The health benefits associated with soy products, coupled with changing preferences towards vegetarian diets, have fueled the growth of tofu production. As a result, the amount of tofu whey has also increased proportionally. Alcoholic fermentation can serve as an alternative method to convert tofu whey into food products that can be consumed directly,” explained Assoc Prof Liu.
Jian Yong has given the beverage a Japanese-inspired name of ‘Sachi’, which means “blossoming wisdom”, given the drink’s “sake-like profile”, as he explained. Sachi has a pale yellow tint, tastes sweet with fruity floral notes, and more interestingly, has no hint of soy bean flavour. This is thanks to his novel fermentation process, which transforms the original taste and odour of tofu whey into a fruity, sweet flavour. It is a light alcoholic drink, with about 7 to 8 per cent alcohol content, which is lower than most wines and sakes.
Creating Sachi takes about three weeks — from making fresh soy milk from soybeans and using soy milk to make tofu, to collecting whey and fermenting it with a mixture of sugar, acid and yeast.
The NUS team has filed a patent for this novel beverage and is currently seeking opportunities for industry collaboration. Jian Yong is also working on fine-tuning his recipe and hopes to extend the shelf life of the drink beyond the current four months without using preservatives.
See press release.