Effect of Complexing Agents on Whey Protein Precipitation

Chitosan and pectin are natural complexing agents that exert different effects on protein precipitation from cheese whey. The authors compared them as individual complexing agents to develop an economically and technologically feasible method for processing secondary dairy raw materials. The study focused on the effect of process parameters (pH, temperature, precipitant concentration, and process time) on protein extraction from reconstituted cheese whey with 6.0% solids. Chitosan gel achieved a maximum protein precipitation efficiency of 26.51% under the following conditions: pH 4.5, 10–20 °C, 1.0–1.5% chitosan, and 20–80 min. Neutralized chitosan gel and lower temperatures improved process efficiency. Citrus pectin demonstrated a higher performance (19.28%) than apple pectin (15.66%). However, both pectins were inferior to chitosan in terms of precipitation capacity. Precipitating whey proteins with natural complexing agents proved feasible under mild temperatures. They required no high-temperature treatment, which is critical for reducing energy consumption in industrial applications. Further research will investigate the synergistic effect of chitosan and pectin on selective protein fractionation, as well as provide a techno-economic comparative analysis with existing industrial whey processing methods.