Characteristics of soybean sprout locally cultivated in the Jeonju region, used for Bibimbap and Kongnamul-gukbap

Background: Jeonju has been named by United Nations Educational, Scientific and Cultural Organization (UNESCO) as a Creative City of Gastronomy since 2012. The title was awarded based on foods and traditional culture. Jeonju's homemade food preparation style, which has been passed down for thousands of years, was highly praised. Jeonju bibimbap and kongnamul-gukbap are the representative foods of Jeonju city. Soybean sprout cultivated locally in the Jeonju region is famous for being one of the “Jeonju 10 delicacies”, and is one of the essential food ingredients in Jeonju bibimbap and kongnamul-gukbap. This study was conducted to provide basic data on why Jeonju soybean sprout has been famous nationwide for a long time. Methods: The analyses of proximate components, minerals, vitamin C content, and sensory evaluation using quantitative descriptive analysis were conducted on raw soybeans and soybean sprouts cultivated using groundwater from Jeonju, along with raw domestic soybeans, and Chinese soybeans from other regions. Results: Soybean sprouts cultivated with groundwater from the Jeonju region resulted in a sweeter taste and a more delicious and crunchier texture. It also resulted in a less undesirable ‘beany’ flavor. As a result, these soybean sprouts are superior overall compared with those grown in other regions regardless of the fact whether the origin of the raw material was domestic or from China (p < 0.001). Even though the soybean sprouts cultivated from Chinese soybeans were very good in the overall acceptability, they had a grassy and bean-like flavor because of a high linolenic acid content. Conclusion: Soybean sprouts cultivated using Chinese soybeans in Jeonju were better in the overall acceptability than those grown in other regions because the Jeonju product contained two to three times less amino acids, such as leucine, tyrosine, and phenylalanine, than the other regional products, which tasted bitter. The cultivating water may affect the free amino-acid content of soybean sprouts and their taste.