Stability, bioavailability and antifungal activity of reuterin during manufacturing and storage of stirred yoghurt

• Published in: International dairy journal 2021-10, Vol.121, p.105141, Article 105141
• Main Authors: Pilote-Fortin, Hélène, Ben Said, Laila, Cashman-Kadri, Samuel, St-Gelais, Daniel, Fliss, Ismail
• Format: Article
• Language: English
• ISSN: 0958-6946; 1879-0143
• DOI: 10.1016/j.idairyj.2021.105141

High purity reuterin was produced by bioconversion of glycerol using Lactobacillus reuteri and was tested for its bioavailability and antifungal activity in milk and stirred yoghurt. Natamycin was used as a control. In whole milk (3.25% fat) reuterin showed significant inhibition of Rhodotorula mucilaginosa, Aspergillus niger, Penicillium chrysogenum and Mucor racemosus by agar diffusion assay. Minimal inhibitory concentrations ranging from 1.89 mm to 7.58 mm for reuterin and from 0.005 mm to 0.16 mm for natamycin were obtained using the microtitration assay. The inhibitory activity of reuterin was shown to be fungicidal; that of natamycin was fungistatic. In stirred yoghurt kept at 4 °C, addition of reuterin at 10 mm allowed total inhibition of M. racemosus and R. mucilaginosa within 1 week and reduced A. niger counts by 3 log cycles over 4 weeks. The addition of reuterin increased the final pH of the stirred yoghurt and decreased the acidity.