Beta 1


Title Bakterier in syrnede mælkeprodukter
Author Dehli, Tore Ibsen (BioScience and Technology, BioCentrum-DTU, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Nordvang, Rune Thorbjørn (BioScience and Technology, BioCentrum-DTU, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Supervisor Westermann, Peter (BioScience and Technology, BioCentrum-DTU, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Bachelor thesis
Year 2007
Abstract På det danske marked findes en række syrnede mælkeprodukter og naturlægemidler, der hævder at have en gavnlig effekt på brugeren, som følge af et indhold af mælkesyreproducerende bakterier. Flere mælkesyreproducerende bakteriestammer er klassificerede som probiotika. Denne betegnelse gennemgås i rapporten og kan muligvis anvendes til at give et overblik over disse gavnlige produkter. Det er undersøgt om betegnelsen probiotika er beskrivende for bakterieindholdet i udvalgte produkter. Det er i høj grad er tilfældet. Alligevel rejser rapporten spørgsmålstegn ved anvendeligheden af den nuværende definition af probiotika. I dette projekt er ni forskellige produkter, med et påstået bakterieindhold, udvalgt og bakterieindholdets art og mængde er undersøgt, for at afgøre om produkterne lever op til deres varedeklaration. De opnåede data er sammenholdt med et litteraturstudie af de pågældende bakterier, for at afgøre om produkterne kan gavne brugeren. Det er generelt tilfældet. Med de, i projektet, anvendte metoder har det vist sig muligt at gro alle bakteriearter i produkterne og derved bestemme hvilke, og hvor mange, levedygtige bakterier de indeholder. Artsbestemmelsen er sket ved en databasesøgning med 16S rDNA-sekvenser fra produkterne, der er opnået ved at amplificere og sekventere bakteriernes 16S rRNA-gen. Mængden af bakterier i produkterne er bestemt ved anaerob udpladning, inkubering og optælling af kolonier på definerede faste medier. Undersøgelsen viser, at majoriteten af produkterne overholder, hvad de angiver i varedeklarationen. Otte af ni produkter kan betegnes som probiotiske.
Abstract A number of fermented milk products and natural medicinal products, claiming to have a positive effect on the user due to their contents of lactic acid producing bacteria, are present on the Danish market today. Several strains of lactic acid producing bacteria have been classified as probiotics. This designation is reviewed in the report and might be applicable to give an overview of these beneficial products. It is examined whether the designation probiotic is descriptive for the bacterial contents of selected products. This is the case to a great extent. Even so, the report questions the applicability of the current definition of probiotics. Nine different products, claiming to have a bacterial content, have been selected and examined with regard to amounts and species of bacteria, to decide whether they live op to their informative label or not. The acquired data has been compared to at literature study of the bacteria under review, in order to decide if the products can be beneficial to the user. This is generally the case. With the applied methods we have been able to grow all bacterial species present in the products and thereby determine which, and how many, viable bacteria they contain. The species determination is carried out through a database search with the 16S rDNA sequences from the products, which have been obtained be amplifying and sequencing the bacteria’s 16S rRNA gene. The amount of bacteria in the products has been determined by anaerobic plating, incubation and counting of colonies on defined solid media. The study shows that the majority of products contain what is stated on the informative label. Eight of nine products can be designated as probiotic.
Imprint Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Pages 71
Admin Creation date: 2010-07-01    Update date: 2010-07-01    Source: dtu    ID: 264528    Original MXD