ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
As part of a program to reduce the flatulence-inducing tendency of soy milk, a method for the enzymatic removal of galacto-oligosaccharides by means of an enzyme preparation from Aspergillus saitoi was investigated. It was found that a partially purified preparation possessing both α-galactosidase and invertase, yet free from protease, could be obtained easily from a commercial A. saitoi acid-protease product by means of a simple molecular sieving procedure. The α-galactosidase exhibited its optimum pH between 5.0 and 5.5, and seemed to be stable between pH 4.0 and 8.0. The optimum temperature was found at about 55°C; however, the enzyme itself was inactivated by maintaining it at 70°C for 30 min. These properties appeared suitable for the enzymatic treatment of soy milk. p-Chloromercuribenzoate, N-bromosuccinimide, HgCl2, AgNO3 or CuCl2 showed strong inhibitory effects on the enzyme. The presence of 1 x 10-2M galactose caused only slight inhibition. Km value of the enzyme with melibiose as a substrate was found to be 3.11 x 10-3M and the molecular weight of the enzyme estimated to be about 290,000 on the basis of a gel filtration technique. Investigations by means of thin-layer chromatography indicated that the addition of small amounts of this enzyme preparation to soy milk resulted in complete hydrolysis of galacto-oligosaccharides. The practicability of the present method was also discussed from an economic viewpoint.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1970.tb04836.x
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