Use of Response Surface Methodology to Investigate the Effectiveness of Commercial Enzymes on Buckwheat Malt for Brewing Purposes
Blaise P. Nic Phiarais1,3, Beatus D. Schehl1,3, Jorge C. Oliveira2 and Elke K. Arendt1,4
1 Department of Food and Nutritional Sciences, National University of Ireland, University College Cork, College Road, Cork, Ireland.
2 Department of Process and Chemical Engineering, National University of Ireland, University College Cork, College Road, Cork, Ireland.
3 Biotransfer Unit, National University of Ireland, University College Cork, College Road, Cork, Ireland.
4 Corresponding author. E-mail: e.arendt@ucc.ie
J. Inst. Brew. 112(4), 324–332, 2006 | VIEW ARTICLE
ABSTRACT
The influence of two factors, total concentration and fraction of three pairs of commercial enzymes, which showed statistical significance (Biocellulase W with Hitempase 2XL, Biocellulase W with Amylo 300 and Amylo 300 with Hitempase 2XL), were studied for their overall effect on buckwheat wort quality using response surface methodology (RSM). This study revealed that the addition of increasing levels of Hitempase 2XL to the buckwheat mash increased colour, extract levels, wort filtration, fermentability and total fermentable extract (TFE), along with decreasing viscosity values. Results also determined a high level of fermentability when an enzyme combination of 30% Biocellulase and 70% Hitempase was added to the mash. The addition of increasing levels of Amylo 300 to buckwheat mashes resulted in increases in fermentability and total fermentable extract (TFE), along with increases in total soluble nitrogen (TSN), free amino nitrogen (FAN) and Kolbach index (KI). With regard to the proposed optimal regime, although no synergistic effect was found when the three enzymes were used together, the optimum conditions for the production of buckwheat wort with lowest viscosity, highest extract and optimal fermentability were achieved using a joint model. Overall, the findings of this study demonstrate the feasibility of producing wort suitable for the brewing of glutenfree beer from 100% malted buckwheat with careful optimization of enzyme types and dosage levels.
Key words:
Buckwheat, enzyme activity, response surface methodology, wort quality.
Publication no. G-2006-1308-459 ©2006 The Institute & Guild of Brewing