Recent research finding

No.43 Protective effect against inactivation of protease in fruits by α-cyclodextrin



Protease in fruits can promote digestion and gastrointestinal absorption of the hydrolyzed proteins which are contained in meat.

But the use of the protease to the food processing is difficult, because the activities are reduced when they are heated more than 60℃.

In this study,
we explored the stabilization of the kiwi protease in kiwi juice and kiwi powder with cyclodextrin.

Fig 1 The effect of CD to enzymatic activity of kiwi juice.

The color of Kiwi juice turned to brown and the enzymatic activity was reduced by oxidation with two days storage.

Inactivation of kiwi protease was not observed by addition of CDs, especially αCD.

Fig 2 Powderization of kiwi juice

Powderization of kiwi juice shows some advantages, for example delaying the corruption and easy handling.

Fine powder of kiwi juice was easily prepared by addition of αCD or γCD.

Fig 3 Thermo stability of kiwi powder in the presence of CDs.

Inactivation of protease in kiwi powder by heating (70℃・5min).

αCD powder was more stable than other kiwi powder samples in high temperature condition.


αCD and γCD can make kiwi powder finely from kiwi juice.
The highest thermostability of kiwi protease was observed in the case of kiwi juice with αCD and kiwi-αCD powder.

These results showed that αCD can be stabilizing reagent of protease in kiwi, and can apply it to food processing