• The Korean Journal of Food And Nutrition
• /
• v.11 no.5
• /
• pp.561-564
• /
• 1998

The stabilizatio of amaylolytic enzyme such as $\beta$-amylase of barley, $\beta$-amylase of wheat, $\beta$-amylase of sweet potato, $\alpha$-amylase of Bacillus licheniformis, $\alpha$-amylase of Aspergillus sp. and $\alpha$-glucosidase of Aspergillus awamori was attained by modification with periodate-oxidized soluble starch. The pH stability of modified enzyme was increased at pH 9 for $\beta$-amylase of sweet potato, pH 3~5 and 8~11 for $\beta$-amylase of barley, pH 2~3 and 7~12 for $\beta$-amylase of wheat and pH 6 for $\alpha$-glucosidase of Aspergillus awamori. Thermal stability increased 17.6% for $\alpha$-amylase of Aspergillus sp. at 6$0^{\circ}C$ for 10min, 30% for $\alpha$-amylase of Bacillus licheniformis at 10$0^{\circ}C$ for 5min and 4.5% for $\alpha$-amylase of sweet potato at 6$0^{\circ}C$ for 10min compared with those of native enzymes.

• The Korean Journal of Food And Nutrition
• /
• v.13 no.4
• /
• pp.348-352
• /
• 2000

The stabilization of wheat $\beta$-amylase( Himaltosin GL, Hankyu-Bio) was attained by modification wish periodate-oxidized soluble starch. The specific activities of modified enzyme at pH 9.7 and pH 8.0 were 17% and 96%, respectively, compared with that of native enzyme. The pH stability of modified enzyme was increased at pH 2~5 and 6~12 in the presence of $\alpha$-cyclodextrin( $\alpha$-CD) compared with that of native enzyme, and optimum pH of the enzyme was changed from pH 5.0 to pH 7.0 by the modification. Thermal stability of the modified enzyme was increased. After treatment at 6$0^{\circ}C$ for 10min, the activity remained 8% for the enzyme modified at pH 8.0 in the presence of $\alpha$-CD and tested in the presence of $\alpha$-CD, 5% for the native enzyme. The native enzyme and modified enzyme showed one peak in HPLC. The molecular weight of the modified enzyme was slightly increased in HPLC analysis.