Research Article
Valeria Sagheddu*, Marina Elli
Abstract
The ability of probiotics to survive the gastric transit to the low pH value of the stomach represents one of the key features associated to their effectiveness. Two strains of L. rhamnosus were evaluated for their ability, when supplied through diverse food matrices, to survive the exposition to four different simulated gastric juices. Probiotics were cultured in MRS broth medium, used as conventional control, as well as in carrot juice, rice cream and cow’s milk in order to define the protecting role of the food matrix to the harsh gastric conditions. Fermented cow’s milk was chosen as a reference for its well-known protective role towards probiotics. Matrices of vegetable origin were evaluated for their potential in preserving probiotic viability following ingestion. Results obtained were promising since fermented carrot juice should be considered as a potential alternative to dairy-based products. On the contrary, rice cream offered less protection to probiotics bacteria when exposed to simulated gastric juices and its effect was strain-dependent. Our preliminary work offers new insights to elucidate the role of food matrix in protecting probiotics when exposed to challenging conditions with particular reference to special dietary conditions like deprivation of dairy-based products and/or vegetarian/vegan regimens.