Changes in volatile aroma profiles of soybean, rice, and wheatkojiduring fermentation using stir bar sorptive extraction followed by gas chromatography‐mass spectrometry and descriptive sensory analysis

Abstract

AbstractDoenjang, a fermented soybean paste, is a traditional food ingredient in Korea. While the flavor ofdoenjangis heavily dependent onkoji, studies on the aroma characteristics ofkojiremain limited. This study aimed to determine the changes in the aroma profiles of soybeankoji(SBK), ricekoji(RK), and wheatkoji(WK). Aroma analysis was performed using stir bar sorptive extraction followed by gas chromatography‐mass spectrometry (GC‐MS) and descriptive sensory analysis. In SBK, bean‐associated aroma was strongly developed due to the lipid‐derived compounds, whereas in RK, sweet aromas were relatively strong at 72 h due to the sweet‐smelling ester compounds. In WK, the nutty cracker attribute was significantly strengthened during fermentation due to the high concentration of aldehydes. The results showed that the aroma profile ofkojiwas influenced by main ingredient, and this finding is useful in improving aroma development with the use ofkojiin the fermented food industry.Practical ApplicationKojiis one of the key ingredients utilized in commercializeddoenjangmaking process in Korea, in order to accelerate the fermentation process. In this study, influences of raw materials ofkojiin the aroma development ofdoenjangwere investigated using descriptive sensory analysis and instrumental flavor analysis using GC‐MS. Raw material‐driven aroma compounds were documented in differentkojisamples, in which influences the aroma characteristics ofdoenjangmade withkojimade with different raw materials. Finding from this study can aiddoenjangmanufacturers for versatile aroma development of commercializeddoenjang.