Enrichment of Vanillin in Barley Malt by Hydrolysis in High Temperature and High Pressure Steam

Malted barley was treated with saturated steam at temperatures ranging from 180 to 220 °C, that is, high temperature and high pressure steam (HHS), and a control sample exposed to saturated liquid water in the same temperature range. The malt treated in steam was extracted with water (70 °C) for 15 min after drying. Vanillin which gave beer preferable flavor was detected in all malt extracts, both after treatment with steam and in effluent from malt exposed to liquid water. Hydrolysis of ingredients in the malt occurred even in steam. The treatment of natural products in HHS could be a new thermal technique to provide a special ingredient for food industry, for example, malt for beer.