Survival and bone-active properties of bovine lactoferrin supplemented into stirred yoghurt

Bovine lactoferrin dosed at up to 0.15% (w/w) into stirred yoghurt and added either prior to, or immediately following, fermentation with a common commercial starter strain containing Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, retained both structural integrity and in vitro bone bioactivity, and had no apparent deleterious effect on some basic physical and sensory properties of yoghurt. Furthermore, the yoghurt could be stored for up to 21 days at 4 °C with no apparent change in lactoferrin structure as demonstrated by immunochemical assays and spectrophotometric iron-binding assays. Importantly, it has been demonstrated that lactoferrin can be supplemented into yoghurt and the yoghurt maintained for at least 21 days at 4 °C without lactoferrin losing its osteogenic activity as measured in primary bone-forming cell cultures.