DBPapers
DOI:10.5593/SGEM2013/BF6/S25.020

PHYSICOCHEMICAL MONITORING OF THE FERMENTATION OF MIXED CEREAL-BASED SUBSTRATE TO OBTAIN A FUNCTIONAL BEVERAGE

M. L. Pacala, L. Brudiu, E. Lengyel, D. Stegarus, M. Begea
Tuesday 6 August 2013 by Libadmin2013

References: 13th SGEM GeoConference on Nano, Bio And Green – Technologies For A Sustainable Future, www.sgem.org, SGEM2013 Conference Proceedings, ISBN 978-619-7105-06-3 / ISSN 1314-2704, June 16-22, 2013, 211 - 218 pp

ABSTRACT

In this article was monitorized the fermentation of mixed cereal-based substrate by analyzing the main physical-chemical characteristics (pH, total and volatile acidity, alcohol concentration, dynamic viscosity, total dry matter and colour) of the fermented mashe obtained from ground debranned white millet (Panicum miliaceum), degermed extra corn flour (Zea mays var. amylacea), whole Spelta wheat (Triticum spelta), Caraamber barley malt (Weyermann Specialty Malting, Germany) and fine common wheat (Triticum aestivum) bran and water. Cereals grinding was done at 0.1 mm disc gap for debranned millet and to 0.4 mm for barley malt and wheat. The ratio between of used grist quantities (in the order shown above) to obtain the mash was 3:1:1:3:2 w/w/w/w/w. Initial dilution was 1:12 w/w and final dilution was 1:9 w/w. Before fermentation was added 10% w/w white crystalline sugar and sweet mashes were inoculated with single and mixed starter cultures represented by wheat beer yeast and mesophilic lactic acid bacteria (LAB), incubated at 30 ºC for 13 h and then stored at 6ºC for 70 h. All determinations have made in triplicate and data are shown as mean ± SD. It was found that fermentation with LAB, comparative with wheat yeast, determine more pronounced decrease of pH, but total acidity is higher when using unique starter culture of yeast, for both series. Alcoholic concentration of cereal-based beverages was significantly higher when the inoculum contains yeast. For both series of fermentation is recommended the mixed starter cultures and of these the one with lower inoculum; dynamic viscosity is significantly influenced by alcoholic concentration for lower inoculum.

Keywords: cereal substrate, yeast, lactic acid bacteria, fermentation, beverage