Influences of appearance characteristics on consumer perception of ‘gu-soo’ in fermented soybean paste (doenjang)

Doenjang, one of the representative soybean-fermented foods in Korea, is a widely consumed food ingredient of stew, soup, and sauce/dip. In Korea, the term ‘gu-soo’ is widely used to describe sensory characteristics of doenjang. Previous studies have reported that appearance characteristics such as colour, moisture content, and bean-to-paste ratio may affect consumer perception of gu-soo in doenjang. The purpose of this study was to determine effects of appearance characteristics such as colour and bean-to-paste ratio on consumers' perception of gu-soo in doenjang. A total of nine doenjang samples with three different colours and three different bean-and-paste ratios (0%, 25%, and 50%) were prepared. Consumer (N = 101) tests were conducted to measure consumer perception and acceptance of nine samples. Check-all-that-apply (CATA) test on sensory characteristics perceived by each doenjang was also conducted. As a result of the CATA test, doenjang samples made of the same type of doenjang were perceived to have similar sensory characteristics. Having high levels of beans in the paste did not affect the liking attribute or consumer perception of ‘gu-soo’ in doenjang (P > 0.05). Overall, consumers' perception of gu-soo were influenced by the colour of doenjang (P < 0.05). This study found out that the colour of doenjang was more important in consumer perception of ‘gu-soo’ in doenjang than bean content in the paste.