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Malolactic bioconversion using a Oenococcus oeni strain for cider production: effect of yeast extract supplementation
Mónica Herrero1, Luis A García, Mario Díaz
1Department of Chemical Engineering and Environmental Technology, Faculty of Chemistry, University of Oviedo, C/Julián Clavería s/n, 33071 Oviedo, Spain.
Journal of Industrial Microbiology & Biotechnology
|January 10, 2004
Summary
Fermentation lees from cider can replace commercial yeast extract for malolactic starter cultures. Harvesting cells in the late exponential phase maximizes malic acid degradation for efficient cider fermentation.
Area of Science:
- Enology
- Food Microbiology
- Biotechnology
Background:
- Yeast extract enhances malolactic starter cultures for cider production.
- Commercial yeast extracts can be costly for industrial applications.
Purpose of the Study:
- To evaluate fermentation lees as a sustainable alternative to commercial yeast extract.
- To determine the optimal harvest time for malolactic starter cells based on enzymatic activity.
Main Methods:
- Malolactic enzymatic assays were performed on whole cells and cell-free extracts.
- Cells were harvested at different growth phases, focusing on the late exponential phase.
- Malic acid degradation was monitored during controlled cider fermentation.
Main Results:
- Fermentation lees effectively supported malolactic starter culture development.
- Cells harvested at the late exponential phase exhibited maximum specific malolactic activity.
- Malic acid degradation rates in fermentation media were lower than in enzymatic assays but showed industrial applicability.
Conclusions:
- Cider fermentation lees are a viable and cost-effective substitute for commercial yeast extract.
- Harvesting malolactic starter cells during the late exponential phase optimizes malic acid bioconversion.
- The study provides valuable insights for improving industrial cider fermentation processes.