Impact of oxidoreduction potential and of gas bubbling on rheological properties of non-fat yoghurt

Use of gases to improve survival of Bifidobacterium bifidum by modifying redox potential in fermented milk

“…Milk is an oxidizing medium when in contact with air; nitrogen, which is neutral, can be used to remove oxygen from milk. Even so, the milk E h remains oxidizing, whereas hydrogen provides a reducing E h (below 0 mV; Martin et al, 2010). The production of lyophilized probiotic bacteria (Lactobacillus casei) was previously tested with an increase in survival during storage (Cachon et al, 2008).…”

Redox Potential: Monitoring and Role in Development of Aroma Compounds, Rheological Properties and Survival of Oxygen Sensitive Strains During the Manufacture of Fermented Dairy Products

“…In yoghurt, solid particles include milk proteins, lactic acid bacteria and their EPS. Indeed, the gel of yoghurts produced under N2 -H2 conditions is weaker despite greater EPS production [23]. It is a common assumption that EPS produced by bacteria contribute to the rheological properties of yoghurt [31][32][33] but, as reported by Hassan et al [34], van Marle [35] and Martin et al [23], no correlation between the viscosity of yoghurt and EPS concentrations was found.…”

“…In a second step, the authors proposed studying the extent to which lactic acid bacteria affect acid milk gelation under different Eh conditions [23]. Indeed, oxygen modifies the growth capacity of bacteria and the formation of end products.…”

“…So, Eh may contribute to the quality of fermented products [2,24,25]. Martin et al [23] wanted to determine the effects of Eh on yoghurts made under various gaseous conditions. In this study they focused on exopolysaccharide production and gel structure ( Table 2).…”

“…Whey separation of yoghurts produced under different Eh conditions over 28 days of storage was then studied [23] (Table 2). Concerning GDL-gels, whey separation of yoghurts occurred from the very first day of storage and the volume of whey separation was relatively constant over the 28 days of storage.…”