Optimization Method And Analysis For Water-soluble Bioactive Substances Content In Soybean Products

The methods for the detection of isoflavone and oligosaccharide by the High Performance Liquid Chromatography (HPLC) were optimized in this paper. And it also analyzed the content of the active factors, such as peptide, isoflavones, saponin and oligosaccharide, in kinds of frequently used soybean products. The main conclusions are followings:1. The best detecting conditions of isoflavone were included by a UV detector, a C18column (150mm×4.6mm,5.0μm), mobile phase A containing0.1%(v/v) acetic acid in ultrapure aqueous, mobile phase B containing0.1%(v/v) acetic acid in methanol, a gradient mobile phase at260nm, a flow rate of0.8mL/min., the four different kinds of isoflavones can be well separated and detected, which showed good linearities and the correlation coefficient of Daidzin, Genistin, Daidein, Genistein were0.9992,0.9991,0.9993,0.9994respectively.2. The best detecting conditions of raffinose and stachyose were included by a refractive index detector, α4.6×250mm,5μm NH2column with a detection temperature of35℃, the flow velocity of1.0mL/min, and the acetonitrile/water ratio of65:35. Under this condition, the detection range of raffinose and stachyose were2.00-10.00mg/mL and4.00～40.00mg/mL, and the average recoveries were95.68%and95.08%, respectively.3. Analysis for water-soluble bioactive substances content in different soybean products. The sequence of water-soluble peptide content in different soybean products was:soy peptides powder>fermented bean curd>lobster sauce>soy protein powder> soya-bean milk> soymilk> thin sheets of bean curd> tofu; the sequence of water-soluble isoflavone content in different soybean products was:soya-bean milk>soy protein powder> soymilk> fermented bean curd> lobster sauce> tofu> soy peptides powder>thin sheets of bean curd; the sequence of water-soluble soyasaponone content in different soybean products was:tofu> thin sheets of bean curd>soy protein powder> lobster sauce> soymilk>fermented bean curd> soy peptides powder> soya-bean milk; the sequence of water-soluble oligosaccharides content in different soybean products was: tofu>soy peptides powder> thin sheets of bean curd>soya-bean milk>soymilk>soy protein powder> lobster sauce> fermented bean curd.4. Analysis for water-soluble bioactive substances content in different soybean products. The sequence of water-soluble peptide content in different soya-bean milk was: flavor soya-bean milk>sweet soyabean milk>reducing sugar soya-bean milk>KFC soya-bean milk; the sequence of water-soluble isoflavone content in different soya-bean milk was:KFC soya-bean milk> flavor soya-bean milk> sweet soyabean milk> reducing sugar soya-bean milk; the sequence of water-soluble soyasaponone content in different soya-bean milk: flavor soya-bean milk> sweet soyabean milk>reducing sugar soya-bean milk; the order of water-soluble oligosaccharides content in different soya-bean milk: flavor soya-bean milk> sweet soyabean milk>reducing sugar soya-bean milk>KFC soya-bean milk.5. The content of water-soluble protein, water-soluble peptide and water-soluble isoflavone in homemade soya-bean milk by non-genetically modified soybeans were higher than which in homemade soya-bean milk by genetically modified. However water-soluble soyasaponone and oligosaccharides content were lower than which in homemade soya-bean milk by genetically modified.