| abstract |
The present invention includes a 2,5-piperazindioone, 3,6-bis (phenylmethyl)-, (3S, 6S)-which is a useful substance having an improvement effect on learning motivation, in an easy form and high concentration. It is aimed at providing an extract or a beverage. The content between 2,5-piperazindione, 3,6-bis (phenylmethyl)-, (3S, 6S)-(in μg / 100 g) and Brix (Bx) is 6 (μg / 100 g) Extracts or beverages above / Bx may be consumed over a long period of time as foods and beverages useful for improving learning motivation. |