電子レンジによるグルタミン酸脱炭酸酵素の失活について  [in Japanese] Studies on Thermal Inactivation of Glutamate Decarboxylase by Electromicrowave Irradiation  [in Japanese]

電子レンジにより熱処理したカボチャ,西洋ニンジンのグルタミン酸脱炭酸酵素の活性を測定し,従来の加熱調理方法と比較検討した。その結果,カボチャ,西洋ニンジンいずれの場合も,蒸調理した場合は大部分の酵素活性が保持されているのに対し,電子レンジにより加熱処理した場合には,その活性がほとんど矢なわれることが認められた。これらのことから電子レンジによる調理方法は,従来の加熱調理に比べ,スピーディーに本酵素を失活せしめ,従って,うま味成分であるグルタミン酸の保持という点から,望ましい調理方法であると考察された。終りに,電子レンジを利用させていたゞきました本学調理学研究室の皆さんに,又実験に協力して下さった本学44年度,栄養学特殊研究生 大村茂子,重住江里子両嬢に謝意を表します。

It has been found that cooking of carrot and pumpkin in electronic range destroys the glutamate decarboxylase activity extensively while that by steam heating remains greater parts of the enzyme active. Carrot and pumpkin were cut into slices and steamed or irradiated by electromicrowave in a commercial electronic range for 2 minutes. The heated samples were homogenized in a medium containing 0.1M phosphate buffer (pH 5.8) and the homogenates centrifuged at 3000rpm for 20 minutes. The resultant supernatants were used as the enzyme solutions and the activities were determined by estimating colorimetrically the amounts of γ-aminobutyric acid formed on incubation with glutamic acid. Results of the experiments showed that in both carrot and pumpkin the steam heating remained major parts of the enzyme active (more than about 85%) whereas the electromicrowave irradiation destroyed the enzyme nearly completely. It may be concluded that for retaining glutamic acid, a flavor enhancer, in fresh vegetables during cooking, use of an electronic range is preferable to that of steam cooker.