Potato Protein Concentrate: Enhancing Quality Through Sustainable Phenolic Reduction Method

Introduction: Potatoes are a worldwide staple food and a valuable source of high-quality protein. Potato fruit juice (PFJ), a by-product of starch production, contains protein with a complete essential amino acid profile rivaling eggs. However, high concentrations of phenolics in PFJ can impact the taste and other sensory qualities of potato protein concentrate (PPC), making the protein undesired by humans. This study aimed to improve the quality of PPC for human consumption using novel adsorption resins to selectively remove phenolics from PFJ.

Methods: The resins were evaluated for binding phenolics in both pure solutions and PFJ. Resins were categorized as Strong Anion Exchange (SAX), Weak Anion Exchange (WAX), Reverse Phase (RP), and Weak Cation Exchange (WCX). Potato protein was precipitated from resin-treated PFJ using acid and heat, and the total phenolic content (TPC) of the PPC was measured using the Folin–Ciocalteu spectrophotometric method.

Results: The resins demonstrated varying degrees of effectiveness in binding phenolics, with SAX resins showing superior performance. The most effective SAX resin reduced the TPC in PFJ by approximately 3.5 times compared to the control. WAX resins also exhibited notable phenolic reduction capabilities, decreasing TPC by up to 2 times. However, a trade-off between phenolic reduction and PPC yield was observed. The most effective phenolic-binding resin resulted in a lower PPC yield compared to the control, while a moderately effective WAX resin achieved a higher yield, ranging from 60 to 90% of the control.

Conclusions: SAX resins demonstrated superior performance in lowering phenolic content in both PFJ and PPC through adsorption. The findings demonstrate the feasibility of using these specialized resins to enhance the quality of PPC for human consumption. Employing this sustainable method can unlock the full potential of potato protein as a nutritious food ingredient, which can contribute to the development of a more sustainable protein source.