Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2024

Prebiotic potential of Davidsonia pruriens in yoghurt: An in-vitro investigation focussing on product quality and the human gut microbiota (#45)

Thomas Leadbetter 1 , Senaka Ranadheera 1 , Said Ajlouni 1
  1. University of Melbourne, Parkville, VIC, Australia

Davidsonia pruriens, commonly known as Ooray is an Australian native tree from north-eastern Queensland, that produces small purple fruits. These fruits have been linked to positive health effects in human and animal models. Furthermore, these fruits are high in anthocyanins and fibre leading to researchers believing that there is a potential for prebiotic effect. To show that additions of D. pruriens would not affect the physico-chemical properties or microbiological shelf life of yoghurt, comprehensive physico-chemical testing and selective media were used. In addition to this, use of in-vitro­ digestion and colonic fermentation were completed to show that the additions of D. pruriens could increase the length of viability of L. acidophilus in the colon. Pure D. pruriens powder had significant effects on the acidity, pH, and total solids measurements of the yogurt whilst microbiological shelf life was not. Viable counts of L. acidophilus during a colonic fermentation increased 2 log compared to the control faecal homogenate. D. pruriens in concentration of 5% (w/v) in yoghurt at 48 hours of colonic fermentation had a significantly (p=0.024) higher viability count compared to the faecal homogenate. Results from this study show that the addition of D. pruriens into yoghurt as a fruit adjunct remains a viable option. Most importantly, the results showed that 5% (w/v) D. pruriens was able to help L. acidophilus remain viable for longer in a simulated colonic fermentation. Further research to elucidate compounds created from the fermentation of D. pruriens by the human gut microbiome should be completed.