Retention profile on the physicochemical properties of maize cooking by-product using a tight ultrafiltration membrane

Maize cooking water is a common by-product of the agro-food processing industries. Such by-product is a current case of study for the research community. The present study analyzed the physicochemical properties of the extract during the ultrafiltration process at different weight reduction factor (WRF) values using a tight pore size membrane. The permeate samples coming from the filtration process were analyzed in terms of total soluble solids (TSS), total solids content (TSC), turbidity, pH, electrical conductivity, total polyphenols, total carbohydrates, and total organic carbon (TOC). At the end of the ultrafiltration process (WRF = 5), the retention efficiencies were of 100.0%, 78.4%, 30.5%, 32.6%, 43.8%, 75.9%, 79.9%, and 1.9% for TSS, TSC, turbidity, pH, conductivity, carbohydrates, TOC, and polyphenols, respectively. In this regard, it can be noticed that a significant quantity of the polyphenols contained in the initial extract was recovered in the permeate stream. According to the results, the selective filtration of this by-product by membrane technology represents a potential alternative for the recovery of its high-added value compounds. Finally, the highlighted results on polyphenol recovery are analyzed and discussed based on the separation process, molecule and membrane characteristics, and some other phenomena occurred in the recovery.