Extracts and beverages containing 2, 5-piperazinedione, 3, 6-bis (phenylmethyl) -, (3s, 6s) -

摘要

Disclosed are extracts or beverages containing 2,5-piperazinedione,3,6-bis(phenylmethyl)-,(3S,6S)-, and having a pH of 5 and have a ratio between the content of 2,5-piperazinedione,3,6-bis(phenylmethyl)-,(3S,6S)-(unit:μg/100g)and Brix(Bx)is 6(μg/100g)/Bx or more. The extracts and beverages can be ingested continuously over a long period of time as foods and beverages useful for improvement of learning motivation.