A superior binary matrix of maltodextrin and whey protein concentrate for chia seed oil encapsulation through freeze-drying

The present study was designed to evaluate and compare the efficiency of two wall material (WM) matrices—maltodextrin (MD) and gum Arabic (GA) in combination with whey protein concentrate (WPC) for encapsulating chia seed oil (CSO). RSM, a robust and widely recognized optimization tool, was employed to optimize independent parameters: WM ratio (MD-WPC or GA-WPC) (0 to 100%), homogenization pressure (69-207 MPa), and oil content (6-10%). A modified rotatable central composite design with replicated factorial points ensured non-fractional factor levels to study variable interactions on encapsulation efficiency (EE) and α-Linolenic acid (ALA) retention. Optimized CSO microcapsule [OCSO I (MD-WPC)] exhibited EE (81.23%), higher ALA (61.85%) and Ω-3: Ω-6 ratio (3.44) than OCSO II (GA-WPC) under the same optimized conditions. The optimal conditions were; MD/GA:WPC ratio (25%), pressure (172.5 MPa), and oil content (9%). Microcapsule OCSO I demonstrated superior oxidative stability with a significantly (p < 0.05) longer shelf life (24-26 days) compared to OCSO II (16-18 days) and achieved significantly (p < 0.05) higher CSO delivery in the intestinal phase. FTIR analysis confirmed encapsulation integrity, showing low or no peaks associated with free CSO. These findings provide valuable insights for the industry in selecting innovative, economical, and effective WMs for encapsulating bioactive CSO.