Analysis of volatile compounds in rice porridge of different japonica rice varieties in Northeast China

Japonica rice is a widely cultivated and consumed cereal globally. There are many studies on the aroma of japonica rice, but few are on japonica rice porridge. Electronic nose and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) techniques combined with sensory evaluation were used to analyze the volatile compounds of 21 kinds of japonica rice porridges from Northeast China. The results of electronic nose analysis showed that different varieties of rice porridges had distinct aromas, and principal component analysis effectively distinguished between them. A total of 69 volatile compounds were identified by GC-MS, including 19 hydrocarbons, 17 aldehydes, 9 alcohols, 3 ketones, 3 phenols, 5 esters, 4 ethers, 4 acids, and 5 other compounds. Then the odor activity value (OAV) was calculated to determine the contribution of each aroma compound to the overall aroma of rice porridge. Finally, it is found that the key aroma compounds of japonica rice porridge were hexanal, octanal, nonanal, decanal, (E)-2-nonenal, naphthalene, (E, E)-2,4-decadienal, butylated hydroxytoluene, 1-dodecanol, and 2-pentadecanone. This study preliminarily determined the key aroma substances and aroma attributes in japonica rie porridge, which can provide a valuable theoretical basis for selecting rice raw materials in the japonica rice porridge processing industry.