03050naa a2200265 a 450000100080000000500110000800800410001910000180006024500850007826000090016352021800017265000290235265000160238165000130239765000220241065000090243265300150244170000190245670000120247570000220248770000170250970000240252670000210255077302130257119714082015-11-03       2013    bl uuuu     u00u1 u    #d1 aBENEDETTI, S.  aRecovery and concentration of isoflavones of tofu whey using the nanofiltration.  c2013  aThe tofu is a nutritious food produced from the hydro soluble extract of soybean. Among the production steps, a large volume of whey is eliminated during the pressing step. The tofu whey is characterized by high values of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD), considerable protein content, substantial sugars and minerals (coagulants) concentrations , besides presenting low molecular weight molecules as peptides, lipids, and some functional compounds such as isoflavones and oligosaccharides. The objective of this study was the use of tofu whey, using nanofiltration (NF) for concentration of isoflavones. Initially, the influence of pressure, temperature and tangential velocity during the process was evaluated. The experiments were carried out in duplicate at 6 bar, 28 °C and 0.3 ms-1 until reaching a volume reduction factor (VRF) of 4.5. The VRF was calculated as the ratio between the initial volume (L) of the tofu whey used in the feed and the final volume (L) of the concentrate after NF. The quantification of isoflavones was performed using High Performance Liquid Chromatography (HPLC) with photo diode array detector (Model 996) and automatic sample injector (Model 717 Plus) of WATERS ® (Milford, USA). It was used a reverse phase column (YMC Pack ODS-AM ®, 250 mm x 0.4 mm diameter) [1]. Throughout the nanofiltration process of tofu whey, a reduction in the permeate flux with time was observed, typical of membrane separation processes. Concerning the concentration of isoflavones, it can be observed through Figure 1 a significant increase (p &lt0.05) in the concentration of the ?-glycosides and malonyl glycosides isomers. This behavior was also observed by other authors [2] in the concentration of tofu using a nanofiltration membrane. Regarding aglycones, no increase of its concentration in the retentate was noticed. Overall, there was high retention of isoflavones, showing that nanofiltration was effective for concentration of these bioactive compounds. Therefore, the tofu whey has a potential use on the recovery of isoflavones, and that the nanofiltration process is an effective alternative for this purpose.  aFood and Human Nutrition  aIsoflavones  aSoybeans  aNutrição humana  aSoja  aIsoflavona1 aFOGAÇA, L. A.1 aZIN, G.1 aPRUDÊNCIO, E. S.1 aLEITE, R. S.1 aMANDARINO, J. M. G.1 aPETRUS, J. C. C.  tIn: MEMBRANE SEPARATION PROCESSES SYMPOSIUM, 2.; WORKSHOP ON GAS SEPARATION, 1.; WORKSHOP ON IONS SEPARATION AND PRE-TREATMENTS, 1., Rio de Janeiro, 2013. [Abstracts...]. Rio de Janeiro: UFRJ, 2013. 1 CD-ROM.