| Nanofiltration (MWCO 150-300 Da) was evaluated for the recovery of phenolic compounds from the wastewater of the production of yellow mustard protein isolates. High rejections were observed; however, under alkaline pH lower average rejections were shown (0.70) than acidic conditions (0.87). Fluxes of 51.3 L/hm2 and 28.8 L/hm2 were registered under alkaline and acidic conditions, respectively. At low pH, 77% of the phenolic compounds fed to the process were recovered in the retentate. Diafiltration was beneficial only when processing at low pH. The permeate from the nanofiltration process presented a total phenolic content of less than 100 ppm, which suggests the possibility of recycling these effluents to the production of yellow mustard protein isolates. p-Hydroxybenzoic acid was the major phenolic compound found in the waste effluent, and in the products of nanofiltration processing. Sinapic acid constituted a secondary fraction, and derivatives of quercetin and kaempferol were detected. |
