Recent research finding
Taste improvements of herb medicine and health tea by cyclodextrins

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Ilex kuden gcha Tseng (KUNDEN TEA) is a traditional medicinal plant in China known for 2000 years, and as for the medicinal effect, it is paid attention from of old, and the recent research is reported to various actions like prevention, the therapeutic gain, and the effect etc. of the hyperlipemia treatment of improving the antioxidative effect and the immune function on cancer. However, KUNDEN TEA is usually remarkable the person because of the peculiar bitterness and remarkable for drinking. A for drinking method and the beverage that decreases bitterness because various medicinal effects are known are demanded. It is known that there is a sugar absorption controlling effect by the intestinal tract moreover, the extraction thing of Gimnema sylvesta (GS) that is the plant that belongs to the Asclepiadaceae department that grows similarly naturally in India and China has bitterness with the astriction though it is effective for the obesity prevention and the diabetes prevention.

The effect of the decrease of bitterness of making cyclodextrin (CD) coexist with effective herbal medicine and healthy tea for such a health maintenance in addition was examined by five stage evaluation at the bitterness level by the panelist. It turned out that only γCD was KUNDEN TEA, the Gimnema sylvesta extraction thing, and in any case effective in α, β, and γCD.

Reduction of bitter taste of Gymnema Sylvestre (GS)

Reduction of bitter taste of GS by α, β or γ cyclodextrin

Reduction of bitter taste of GS by the γCD

Concentration-dependent reduction effect of bitter taste of GS by α, β or γCD

Reduction of bitter taste of Guava tea Extract (GT)

Reduction of bitter taste of GS by α, β or γCD

Reduction of bitter taste of GS by the γCD

Reduction of bitter taste of KUNDIN TEA Extract (KT)

Reduction of bitter taste of KT by α, β or γCD

method : 7.5g of KT was added to 500g of water(80℃), and extracted for 10 minutes. After filtered, the KT tea was obtained. 1.5g of α, β or γCD was added in 100mL KT tea respectively. Control meant that cyclodextrins were not added in the tea.

5 panelists taste each sample and select the bitterness from the numbers (0, 1, 2, 3, 4, 5)
0: not bitter taste → 5: strong bitter taste

Added CD αCD βCD γCD Control
Panelist A 5 5 1 5
Panelist B 5 5 1 5
Panelist C 5 5 2 5
Panelist D 5 4 1 5

Reduction of bitter taste of KUNDIN TEA Extract (KT) by γ cyclodextrin

Method: 1.5g, 1g, 0.5g or 0.25g of γ cyclodextrin was added in 100 mL KT tea respectively. Control meant that cyclodextrins were not added in the tea.

6 panelists taste each sample and select the bitterness from the numbers (0, 1, 2, 3, 4, 5)
0: not bitter taste → 5: strong bitter taste

Amount of γCD 1.5g 1g 0.5g 0.25g Control
Panelist A 1 1 2 1 5
Panelist B 1 1 2 2 5
Panelist C 1 2 3 3 5
Panelist D 1 2 2 3 5
Panelist E 1 1 2 2 5
Panelist F 1 1 1 2 5

Discussion

Bitterness of the tea of Gymnema sylvestre and KUNDIN TEA was perfectly improved by the addition of equal amount of γCD.
It was necessary for perfect improvement of bitterness to add of equal amount of γCD to the active substance of Gymnema sylvestre extraction.
Harsh taste of Guava tea extract was also improved by the addition of γCD.
αCD and βCD do not have any effect for taste modification.
Because of improvements of taste by the addition of γCD, triterpenoids and the related substances in the herb tea content were formed the inclusion complexes by γCD.