The role of oxygen in the liquid fermentation of wheat bran.
The extensive use of wheat bran as a food ingredient is limited due to its bitter taste and hard texture. To overcome these, some preprocessing methods, such as fermentation with yeast and lactic acid bacteria or enzymatic treatments have been proposed. The current work studied microbial communities, acidification, ethanol formation and metabolite profile of wheat bran fermented in either aerated or anaerobic conditions. In aerated conditions, yeasts grew better and the production of organic acids was smaller, and hence pH was higher. In anaerobic conditions, lactic acid bacteria and endogenous heterotrophic bacteria grew better. Aeration had a large effect on the sourdough metabolite profile, as analyzed by UPLC-qTOF-MS. Anaerobic conditions induced degradation of ferulic and caffeic acids, whereas the amount of sinapic acid increased. Aeration caused degradation of amino acids and hydroxycinnamic acid derivatives of polyamines. The results suggest that the control of oxygen could be used for tailoring the properties of bran sourdough.
Institute of Public Health and Clinical Nutrition, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland. Electronic address: otto.savolainen@chalmers.se.
Otto I
OI
Savolainen
VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT Espoo, Finland; Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari, Via G. Amendola 165/a, 70126 Bari, Italy.
Rossana
R
Coda
VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT Espoo, Finland.
Katja
K
Suomi
VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT Espoo, Finland.
Kati
K
Katina
VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT Espoo, Finland.
Riikka
R
Juvonen
Institute of Public Health and Clinical Nutrition, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
Kati
K
Hanhineva
Institute of Public Health and Clinical Nutrition, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT Espoo, Finland.
Kaisa
K
Poutanen
D000332:Aerobiosis; D001419:Bacteria / Q000378:metabolism*; D001939:Bread / Q000032:analysis* / Q000382:microbiology; D004043:Dietary Fiber / Q000032:analysis* / Q000378:metabolism / Q000382:microbiology*; D005285:Fermentation; D010100:Oxygen / Q000032:analysis* / Q000378:metabolism; D014908:Triticum / Q000737:chemistry / Q000382:microbiology; D015003:Yeasts / Q000378:metabolism*
D004043:Dietary Fiber; D010100:Oxygen
Aeration; Bioprocessing; Mass spectrometry; Sourdough; Wheat bran