Optimum roasting and extraction conditions and flavor characteristics of roasted malt extract

Abstract

Malt was roasted at 235, 245, or 255°C and extracted at 75, 85, or 95°C in hot water for 10, 20, or 30 min. Optimum roasting and extraction conditions were chosen using response surface methodology based on sensory and physicochemical properties. Sensory properties of roasted malt extract produced at optimum conditions were compared with those of roasted barley extract and of commercial barley tea using quantitative descriptive analysis. Flavor compounds in roasted malt extract were identified by gas chromatography (GC) and mass spectroscopy (MS). Correlation between sensory and GC-MS data were calculated. Roasting malt at 240°C and extracting at 75°C for 28 min were found to be optimum conditions for roasted malt extract. The results of sensory and GCMS data indicated that the most dominant flavor compounds in roasted barley and malt were aldehydes and pyrazines.