Research On Preparation Process Of Soybean Oligosaccharide From Tofu Yellow Slurry Water

This paper studied the tofu yellow sourry water as raw material, suing ultrafiltration membrane to extract soybean oligosaccharides, decoloring and desalting purification processing, eventually get liquid soy oligosaccharides, realized the tofu into yellow pulp wastewater.First of all, the main components of the tofu yellow slurry water were tested, including tofu yellow slurry waters solids content of 1.84 %, the content of total sugar of 0.9 %, ash of 0.33 %, nitrogen content of 0.28 %, the content of isoflavones was 0.16 %, the content of saponin was 0.1 3%. Using ultrafiltration process to separate whey of tofu yellow, the best condition of extraction of soybean oligosaccharides was: 10000 intercept molecular weight, temperature 55 ℃, pressure 0.2Mpa, concentration ratio 5 times, under the condition, protein entrapment ratew was 82 %, the oligosacchride through rate of 96 %.And decolorization by active carbon declolring process for raw sugar liquid experiment, single factor experiment and orthogonal experiment ultimately determine the best declolring procss condition was: temperature 50 ℃, p H4.0, 1.5 % of active carbon, decoloring time 40 min, the decolorization rate was 89.21 %.This paper combined electrodialysis and ion exchange resin reaction desalination rate and loss rate of total sugar and to the difficulty of the reaction process as well as to the requirmemnts of the equipment, selected the most appropriate method of desalination. The best desalination technology for ino exchange resin was: desalination rate of 95.89 %, total sugar retention rate of 89.02 %. Best electrodialysis desalination process was: raw sugar liquid dilute 15 times, flow of 60 L/h, the voltage of 15 V, desalination rate of 97.15 %, oligosaccharides retention rate of 85.23 %. This experiment selected electrodialysis desalination. After processing the decolorizing and desalting technology can get clear fluid of soybean oligosacchrides. Soybean oligosaccharide detection using high performance liquid chromatography(HPLC) method, the mobile phase( acetonitrile: water = 70:40) flow rate of 1 m L/min, column temperature 30 ℃, the cell of 35 ℃ environment, three components of soybean ligosaccharides can be separatde effectively, and has godd linear relationship. At the same time to measure the content of total sugar of 7.21 mg/m L, the cottonseed sugar 1.12 mg/m L, stachyose 2.32 mg/m L, sucrose 3.77 mg/m L. Experiments of soybean oligosaccharides fluid of low polyose content is 72.1 %, the conttonseed Sue sugar and stachyose sugar content is 47.7 %, more than the national standard.The functional components in the soy oligosaccharides for cottonseed sugar and stachyose sugar, these functional ingredients can promote intestinal bifidobacterium proliferation, and improve constipation, immunity, anti-cancer effect, ect.