Comparison of quality characteristics of tofu made from three soybean cultivars grown in different regions of Korea

This study examined the physicochemical properties, flavor, and quality characteristics of tofu made from three Korean soybean cultivars (Daewonkong, Seonpung, Seonyu2ho) grown in three different regions (Suwon, Gimje, Daegu) using instrumental analyses. To assess factors impacting tofu’s taste, aroma, and texture, we analyzed the amino acid and fatty acid compositions of the soybeans, along with the taste and aroma characteristics of tofu. Results revealed a correlation between soybean protein content and tofu hardness, with significant compositional differences based on cultivation region; soybeans from Gimje, in particular, showed a higher crude fat content. Using an electronic nose, 41 to 57 volatile compounds were identified across tofu samples, with 2-methylbutane and acetaldehyde as dominant components. Correlation analysis showed positive associations between acetaldehyde and palmitic acid and between 2-methylbutane and oleic, eicosanoic, total, and unsaturated fatty acids. SPME-GC-MS analysis identified 37 volatile active compounds, including alcohols, aldehydes, esters, furans, hydrocarbons, and ketones, with 1-hexanol and 1-octen-3-ol present at significantly higher levels across samples. Among the SPME-GC-MS results, Seonyu2ho-tofu samples exhibited notably higher alcohol levels. Both cultivar and environmental factors substantially influenced tofu’s physicochemical quality and sensory attributes. Since sensory panel evaluations were not conducted, future studies should incorporate panel assessments to further explore correlations between sensory perceptions and instrumental measurements.