| title: | Selection strategies for dairy starter cultures |
|---|---|
| reg no: | ETF6715 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.8. Molecular Biology 1.9. Genetics, Physiology and Microbiology 2.7. Biotechnology, Food and Drink Technology |
| status: | accepted |
| institution: | TTU Faculty of Chemistry and Materials Technology |
| head of project: | Kaarel Adamberg |
| duration: | 01.01.2006 - 31.12.2009 |
| description: | Hundreds of years dairy products were made with spontaneous fermentation. Nowadays high hygienic standards do not allow to use undefined starters in modern technologies where controlled and standardized processes are needed. Especially it failures cheese manufacturing as local microflora gives the characteristic taste and texture to cheeses of specific regions. Nowadays trends require the healthy functional products. One way is addition of probiotic bacteria to dairy products that seems to be the best carrier for these pro-active microorganisms. It has been shown that some bacteria have health-supporting effect to human stabilizing gut microflora, inhibiting the growth of pathogenic bacteria, having immunostimulatoral effects etc. However, the effects of growth stages of bacteria (exponential growth, lag or stationary phases)on the probiotic properties of bacteria (acid and bile tolerance, adhesion to epithelial cells etc.) are not thoroughly studied. We made hypothesis that exponential phase culture is orientated to growth and is not able to quickly adapt stress conditions. It might be crucial in processes where probiotic cultures cannot grow up before stress conditions as other starter bacteria have several times faster growth rate (ex. yoghurt production). Stationary phase culture or heat shock culture might give advantages as in these stages stress protein expressions are activated and probably these bacteria are better to adapt in gut conditions remaining probiotic activites. The aim of this project is 1) to determine the effect of physiological state of bacteria on the probiotic properties, 2) to study the effect of technologically important environmental conditions on the metabolism of bacteria and 3) to select strains suitable for use as adjunct starters, which have probiotic potential. To determine the growth characteristics and select pro-active bacteria we use original accelerostat cultivation technologies and single fermenter gastrointestinal tract simulator. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Kaarel Adamberg | Tallinna Tehnikaülikooli Keemia- ja materjalitehnoloogia teaduskond | ||
| 2. | Signe Adamberg | |||
| 3. | Ingrid Sumeri | |||