Taguchi-Grey relational optimization of spray drying conditions for production of galactooligosaccharides rich paneer whey powder

Paneer whey, a by-product of paneer manufacturing contains high levels of lactose and low concentration of soluble whey protein, is suitable substrate for the preparation of galactooligosaccharides (GOS), a lactose-based prebiotic. In this study, the spray drying parameters were optimized to produce GOS-containing paneer whey powder using a Taguchi experimental design. GOS-enriched hydrolyzed paneer whey was generated using a dual enzyme hydrolysis, and then subjected to spray drying. The optimized conditions—20% gum arabic, 50% feed solids, and 70 °C outlet temperature—yielded powder with low moisture content (1.87 ± 0.09%), acceptable insolubility index (0.5 ± 0.01 mL), high drying yield (51.50 ± 2.54%), and GOS retention (52.43 ± 0.48%). The study highlights the effectiveness of the Taguchi–Grey relational approach in optimizing spray drying parameters and demonstrates the potential of paneer whey as a lactose rich substrate for producing prebiotic rich functional ingredients.