Changes in volatile compounds of waxy rice and gangjeong (a traditional Korean oil-puffed snack) under different steeping conditions

Abstract

Effects of steeping temperature (15, 25, and 35°C) and steeping period (1, 11, and 21 days) on volatile compounds isolated from waxy rice and gangjeong made using steeped waxy rice were evaluated. Six acids, 4 alcohols, 2 carbonyls, 1 furan, and 2 hydrocarbons were detected in waxy rice. Acids and alcohols accounted for the majority of isolated compounds. Compositions of volatile compounds differed according to steeping temperature and time, probably due to changes in microorganisms and enzymes. Forty volatile compounds were isolated from gangjeong made using steeped waxy rice, including 3 acids, 7 alcohols, 10 carbonyls, 1 furan, 10 terpene hydrocarbons, 5 aliphatic hydrocarbons, 2 sulfur-containing compounds, and 2 miscellaneous compounds. Most volatiles were generated via lipid oxidation and decomposition. 2-Pentyl furan was the major volatile compound in gangjeong. Volatile aroma compounds from waxy rice and gangjeong made using steeped waxy rice varied according to steeping conditions and frying processes.