Whey Protein-Pectin Conjugate by Wet-Dry Heating: Optimization usingResponse Surface Methodology with Box-Behnken Design

The recent progress in glycation of proteins utilizing saccharides through the Maillard reaction has garneredsubstantial attention, with a specific emphasis on Whey Protein Concentrate (WPC). Conjugation mode isfrequently intricate and poses challenges when scaling up for large-scale production. Consequently, thisinvestigation sought to optimize the conditions of the WPC-pectin conjugation process using ResponseSurface Methodology (RSM) in conjunction with Box-Behnken design (BBD). The experimentation wasexecuted employing a cabinet dryer, incorporating both wet and dry heating procedures to yield a WPC-pectinconjugate exhibiting favorable functional properties. The independent variables investigated encompassedpectin concentration (ranging from 0 to 1%), pH (ranging from 6 to 8), and drying time (ranging from 2 to 6hours), The measured responses encompassed the emulsion stability index (ESI), emulsifying activity index(EAI), and solubility. Analyzing the experimental data underwent scrutiny for model sufficiency throughdiagnostic plots, and a second-order polynomial equation was fitted through multi-response regressionanalysis, resulting in a high coefficient of determination (R2) value. The most effective parameters wereidentified as a pectin concentration of 0.49%, pH 6.7, and a drying duration of 4.12 hours, yielding a peakESI of 452.267 minutes, EAI measuring 49.95 m2g-1, and solubility reaching 48.09%. Further experimentswere conducted to validate these outcomes, and the presence of the Maillard reaction was confirmed usingFourier Transform Infrared Spectrum (FTIR). The et-dry method demonstrated efficacy in producing WPC-pectin conjugates with commendable functional properties