Seminar: "A scalable method for preparing whey protein isolate-galactooligosaccharide conjugates and application in encapsulating epigallocatechin-3-gallate" -Nanxi Li

"A scalable method for preparing whey protein isolate-galactooligosaccharide conjugates and application in encapsulating epigallocatechin-3-gallate"

Nanxi Li, Ph.D. Student

Rutgers University Department of Food Science

Whey protein isolate (WPI) glycation via Maillard reaction has gained increasing interest as the conjugation can improve WPI characteristics (heat, pH, and ionic strength stability) substantially. In this study, a novel method was developed via wet heating combined with molecular crowding effect and water activity adjustment, and provided a potential approach to produce whey protein isolate-galactooligosaccharide (WPI-GOS) conjugates with high grafting degree (DG, 67.11%) and low browning at industrial scale. Effects of parameters including temperature, pH, heating time, protein and carbohydrate concentrations, and water activity were investigated to determine the optimal reaction conditions. Physicochemical characteristics of the obtained WPI-GOS were evaluated, and the conjugates exhibited good stability across wide ranges of pH, temperature, and ionic strength. WPI-GOS also showed excellent encapsulation efficiency (EE, 88.84%) and loading capacity (LC, 25.38%) of epigallocatechin-3-gallate (EGCG). This novel development opened up promising opportunities to produce other protein-carbohydrate conjugates via wet heating, and provided a new approach to fabricate delivery systems for bioactive compounds.