ABSTRACT: The sensory characteristics and consumer acceptability of beef soup with added glutathione (GSH) and/or monosodium glutamate (MSG) were investigated to examine the feasibility of GSH as a flavor enhancer. The sensory characteristics of beef soup samples, containing only GSH or MSG at different levels or a mixture of these, were examined by descriptive analysis. Principle component analysis was conducted to summarize the relationships between the beef soup samples and the attributes. In consumer testing, separate groups of consumers evaluated overall liking as well as the flavor intensities of beef, seasoning, and MSG. Partial least square regression was conducted to observe the relationships between the descriptive data and consumer data. The samples containing GSH had stronger “beef flavor,”“garlic flavor,” and “green onion flavor” while the samples containing MSG had stronger “salty taste,”“sweet taste,”“MSG taste,” and “potato flavor.” The consumers preferred samples containing both GSH and MSG, which had higher perceived flavor intensities of beef, seasonings, MSG. This study indicates that GSH has potential as a flavor enhancer, but more tests in different food systems with additions of GSH at varying levels are required to elucidate its effectiveness as a flavor enhancer more clearly.