Potato Protein Concentrate: Improving Quality Using a More Effective and Sustainable Method

One ton of potatoes processed to starch yields 5 to 12 m3 of potato fruit juice (PFJ), containing 30–41 wt% per dry matter protein with a high nutritional value that is comparable to eggs and has all essential amino acids. However, high levels of phenolics reduce potato protein concentrate (PPC) quality and taste. This study deployed a sustainable method evaluating novel adsorption resins to bind phenolics in PFJ and improve the PPC. Resins exhibited aqueous phenolic binding capacities ranging from 317 ± 0.5 mg to 606 ± 0.9 mg of Gallic Acid bound per mL of resin. The best performing resin, Strong Anion Exchanger (SAX) 002, significantly reduced PFJ total phenolic content (TPC) from 295 ± 0.6 μg/mL to 84 ± 0.1 μg/mL (Gallic Acid Equivalent (GAE)). Weak Anion Exchanger (WAX) 007 and 008 also decreased TPC to 155 ± 0.2 μg/mL GAE and 154 ± 0.3 μg/mL GAE, respectively. However, the most effective phenolic-binding resin resulted in a lower PPC yield versus control. In contrast, WAX 003 showed moderate phenolic removal but resulted in a higher yield (60 ± 0.69% to 90.1 ± 0.1% of control), demonstrating a trade-off between phenolic reduction and PPC recovery. SAX resins are superior in lowering PFJ and PPC phenolic content through adsorption. The results show the possibilities of using specialized resins to improve PPC quality for human consumption.