title: Fibres as carriers for Lactobacillus rhamnosus during freeze-drying and storage in apple juice and chocolate-coated breakfast cereals.
abstract: The capability of different fibre preparations to protect the viability and stability of Lactobacillus rhamnosus during freeze-drying, storage in freeze-dried form and after formulation into apple juice and chocolate-coated breakfast cereals was studied. In freeze-drying trials wheat dextrin and polydextrose proved to be promising carriers for the L. rhamnosus strains: both freeze-drying survival and storage stability at 37 degrees C were comparable to the control carrier (sucrose). Using apple fibre and inulin carriers resulted in powders with fairly good initial freeze-drying survival but with poor storage stability at 37 degrees C. When fresh L. rhamnosus cells were added into apple juice (pH 3.5) together with oat flour with 20% beta-glucan the survival of the cells was much better at 4 degrees C and at 20 degrees C than with sucrose, wheat dextrin and polydextrose, whereas with freeze-dried cells no protective effect of oat flour could be seen. The stability of freeze-dried L. rhamnosus cells at 20 degrees C was higher in chocolate-coated breakfast cereals compared to low pH apple juice. Similar to freeze-drying stability, wheat dextrin and polydextrose proved to be better carriers than oat flour in chocolate-coated breakfast cereals. Regardless of their differing capability to adhere to fibre preparations the two L. rhamnosus strains studied gave parallel results in the stability studies with different carriers.
authors.affiliation: VTT, Biotechnology, P.O. Box 1000 (Tietotie 2), FI-02044 VTT, Finland. maria.saarela@vti.fi
authors.forename: Maria
authors.initials: M
authors.lastname: Saarela
authors.forename: Ilkka
authors.initials: I
authors.lastname: Virkajärvi
authors.forename: Liisa
authors.initials: L
authors.lastname: Nohynek
authors.forename: Anu
authors.initials: A
authors.lastname: Vaari
authors.forename: Jaana
authors.initials: J
authors.lastname: Mättö
mesh_terms: D001628:Beverages / Q000382:microbiology*; D002099:Cacao; D003912:Dextrins / Q000378:metabolism; D004043:Dietary Fiber / Q000382:microbiology; D002523:Edible Grain / Q000382:microbiology*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D005612:Freeze Drying; D005936:Glucans / Q000378:metabolism; D052201:Lacticaseibacillus rhamnosus / Q000254:growth & development*; D027845:Malus; D011309:Preservation, Biological; D019936:Probiotics; D012995:Solubility; D013696:Temperature; D013997:Time Factors
chemical_list: D003912:Dextrins; D004043:Dietary Fiber; D005936:Glucans; C033375:polydextrose