ARTICLE INFO

ABSTRACT

Received 23 May 2018
Revised 15 Jun 2018

Accepted 03 Aug 2018

The effect of germination process on α–galactosidase activities, oligosaccharides and reducing sugars contents in soybean seeds was investigated. Soaked soybean seeds were germinated at 25^oC in dark condition for 72 hours. Samples were collected every 12 hours during germination for analyzing the α–galactosidase activities, which was monitored with a synthetic substrate ρ-nitrophenyl-α-D-galactopyranoside (ρNPGal). The freeze-dried samples were prepared for determination of raffinose, stachyose, sucrose by thin layer chromatography, and reducing sugars were assayed by reaction with nitro salicylic acid. After soaking, the activity of α–galactosidase increased1.84 times compared to that in the soybean seeds and reached maximum value (164.3±2.5 U/100g, db) after 12 hours of germination. The increase in α–galactosidase activity led to the decrease in raffinose and stachyose contents during soaking and germination. In addition, the degradation of these undesirable components followed the first order exponential equation (R² = 0.97–0.99). Sucrose content remained after soaking and up to 12 hours of germination and reduced significantly after that. The final result of the hydrolysis of raffinose, stachyose and sucrose was significant increase in reducing sugars that can be used as energy-source during germination of soybean seeds.

KEYWORDS

α–galactosidase, germination, oligosaccharides, soybeans, thin layer chromatography

Cited as: Lien, D.T.P., Tram, P.T.B., Trung, T.S. and Toan, H.T., 2018. Changes in α–galactosidase activity and oligosaccharides during germination of soybean seeds. Can Tho University Journal of Science. 54(Special issue: Agriculture): 8-15.