Prebiotics May Protect Probiotics

Scientists at the Technical Research Centre of Finland (VTT), Espoo, Finland, studied whether prebiotics are effective carriers for the probiotic strain Lactobacillus rhamnosus during freeze-drying, storage in freeze-dried form, and after formulation into apple juice and chocolate-coated breakfast cereals.

In freeze-drying trials, wheat dextrin and polydextrose proved comparable to the control carrier (sucrose), with similar freeze-drying survival and storage stability at 37°C.

Apple fiber and inulin carriers showed fairly good initial freeze-drying survival, but had poor storage stability at 37°C.

Oat flour had no protective effect on freeze-dried L. rhamnosus cells. However, when oat flour with 20% beta-glucan was added to apple juice (pH 3.5) with fresh L. rhamnosus cells, survival of the cells was much better at 4°C and at 20°C than with sucrose, wheat dextrin and polydextrose.

When tested in chocolate-coated breakfast cereals, wheat dextrin and polydextrose proved better carriers than oat flour.

Two strains of L. rhamnosus were studied: E-97800 (E800) and E-94522 (E522). They had parallel results in the stability studies, despite their different adhesion properties.

The complete study was published in the Nov. issue of the International Journal of Food Microbiologyhttp://www.sciencedirect.com/science/journal/01681605.