Optimization of the malting process of oat (Avena sativa L.) as a raw material for fermented beverages

Abstract

The influence of the three malting parameters (germination time, germination temperature, and degree of steeping) on the quality of two oat (Avena sativa L.) cultivars was investigated applying response surface methodology. Each predictor variable was tested at three levels, germination of 6 to 8 days; germination temperatures of 12, 15, or 18°C; and degrees of steeping of 43%, 45% or 47%. All analyses were based on methods described in EBC or MEBAK. The oats used were obtained in 2007 from Nordsaat Saatzucht GmbH, Böhnshausen, Germany. A series of malt quality attributes were evaluated including extract, apparent attenuation limit, Kolbach index, α-aminonitrogen, color, β-glucan, and viscosity. Oat malt was optimized based on barley malt specifications, which are considered appropriate in the beverage production industry for optimal processing. For cv. Ivory, the optimal malting program was achieved after 8 days of germination with moisture content of 46%, and at 17°C. Similarly, cv. Typhon required a germination period of 8 days, a moisture content of 47% and temperature of 16°C. The models showed that the value of R2 was high and p- value was significant. Therefore it can be said that the model is highly significant. This project demonstrates that oat is an alternative cereal with potential to be used as raw material in malting and brewing purposes.