Optimizing red sorghum malt quality when Bacillus subtilis is used during steeping to control mould growth

Tawaba, J.B. and Béra, F. and Thonart, P. (2012) Optimizing red sorghum malt quality when Bacillus subtilis is used during steeping to control mould growth. Journal of the Institute of Brewing. pp. 1-10.

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Previous work has shown that Bacillus subtilis-S499-based biocontrol treatments applied without aeration at the steeping stage of red sorghum malting offer good mould reduction, but yield malts with low levels of key hydrolytic enzymes. Thus we attempted to raise these levels by aerating the steeping liquor, varying the steeping time (from 8 to 40 h) and temperature (from 25 to 35 °C), and combining a biocontrol treatment with prior steeping in 0.2% NaOH. Aeration proved particularly important whenever B. subtilis cells were present in the steep liquor. The optimal temperatures for α- and β-amylase were 30 and 25 °C, respectively. By increasing the steeping time, it was possible to improve the α-amylase activity, but the β-amylase activity peaked sharply between 16 and 20 h, depending on the steeping medium. A good compromise was steeping in a biocontrol medium for 14–16 h at 30 °C. Combination steeping treatments (0.2% NaOH for 8 h followed by biocontrol for 8 h) yielded malts of a quality approaching that afforded by dilute alkaline treatment. Copyright © 2012 The Institute of Brewing & Distilling

Item Type: Article
Additional Information: The authors thank the Conseil de Recherche of Gembloux Agrobiotech, for financial support to Jean-Claude Bwanganga in the framework of his thesis.
Uncontrolled Keywords: red sorghum; biocontrol; mould reduction; malt quality; amylases; Bacillus subtilis
Author Affiliation: Gembloux AgroBioTech, University of Liege, Passage des Déportés 2, Gembloux, Belgium, University of Kinshasa, Agricultural Faculty, BP 14071 Kinshasa 1, Democratic Republic of Congo
Subjects: Plant Protection
Crop Improvement
Divisions: Sorghum
Depositing User: Mr. SanatKumar Behera
Date Deposited: 19 Sep 2012 10:40
Last Modified: 19 Sep 2012 10:41
Official URL: http://dx.doi.org/10.1002/jib.36
URI: http://eprints.icrisat.ac.in/id/eprint/7986

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