The positive health effects  of probiotics are why Associate Professor Liu Shao Quan, who is part of the National University of Singapore’s (NUS) Food Science and Technology Programme, has dedicated part of his research to developing new probiotic foods and drinks that could appeal to more people and expand the options for a healthier diet.

Over the past few years, he and his students have created probiotic beer – a first in the market – and two other probiotic beverages made with durian pulp and okara respectively. Okara is soy pulp that is leftover from the production of soy products such as soy milk and tofu.

The probiotics problem

At this year’s Vitafoods Asia 2018 conference, which will take place on Sept 11 and 12 at Singapore’s Marina Bay Sands Expo and Convention Centre, Prof Liu will speak about the difficulties of keeping probiotics alive in foods and drinks, and his research to improve their survival chances.

Prof Liu’s talk is titled “Improving the Viability of Probiotics in Food”. He explained: “Many foods and beverages are acidic, and acids inhibit probiotics’ survival and activity. Besides, when foods and beverages are stored at elevated temperatures, probiotics can grow and produce more acids. This will lead to the probiotics’ death and decrease the health benefits of the foods and beverages.”

He noted that some microorganisms can help to protect probiotics and improve their odds of survival, but the mechanisms of the process are not well-understood. He and his students experimented with different probiotic strains, yeasts and cultures in creating their beverages.

“Beers contain hop acids that prevent the growth and survival of probiotics, but we successfully developed a beer with live probiotics. Our probiotic durian beverage and probiotic okara beverage also have high cell counts of live probiotics,” he said.

Breakthroughs in probiotics

To create the beer, the team experimented with six probiotic strains and varied factors such as the temperature and amount of ingredients during the brewing process. They eventually succeeded with the Lactobacillus paracasei L26 probiotic strain. The beer is also unfiltered and unpasteurised to maintain the live probiotic counts.

Every 100 millilitre of the drink contains 1 billion probiotic organisms, which is the minimum number per serving recommended by the International Scientific Association for Probiotics and Prebiotics to unlock maximum health benefits.

Prof Liu’s research also found that a type of yeast called Williopsis saturnus can be used to significantly improve the survival of the Lactobacillus casei probiotic strain during the fermentation of durian pulp to create durian-based probiotic beverages.

“Using the yeast also produces much higher levels of volatile compounds, including alcohols and acetate esters, which positively contributes to the flavour notes,” he added.

Furthermore, both the probiotic beer and durian beverage are non-dairy products, unlike most probiotic drinks on the market. This means that the NUS scientists’ creations can be consumed safely by people who are lactose-intolerant.

Such flavours are important in the region, where durian is a very popular fruit, and where such ingredients appeal to populations that don’t typically consume milk, such as Thailand and Japan.

Prof Liu said: “When you look at the health benefits that some probiotic strains can confer to humans, mainly in the area of gut health and immunity enhancement, we should try to develop new foods and drinks that can deliver them to people.”

The Asia-Pacific region is now the largest regional market for dietary supplements and vitamins. Across the region, consumers are buying products that are enriched with locally-sourced compounds and functional ingredients.