Valorization of Bombyx mori pupae and Moringa oleifera leaf as sources of alternative protein: Structural, functional and antioxidant properties

Abstract

This study compared protein concentrates extracted from silkworm pupae (SPP) and moringa leaf (MLP) using alkaline extraction followed by isoelectric precipitation with commercial whey protein concentrate (WPC). SPP demonstrated higher protein extraction yield of 5.99 % and protein recovery of 66.02 % compared to MLP (4.39% and 55.27% of extraction yield and protein recovery, respectively). Proximate composition analysis revealed that SPP contained high protein of 65.40 % with ∼13 % fat content, while MLP had lower protein (48.70%) and fat content (0.33%). Particle size analysis showed small mean diameters of ∼123 nm for WPC, ∼192 nm for SPP, and ∼1485 nm for MLP with low polydispersity index (0.35 to 0.51). Secondary structure analysis highlighted β-sheet as predominant in WPC and MLP, while SPP exhibited a major β-turns structure. Solubility studies indicated that SPP had lowest solubility compared to others. In terms of functional properties, MLP exhibited the highest water and oil holding capacities, and foaming capacity, while SPP showed the greatest emulsifying capacity and stability. After passing simulated intestinal digestion, SPP exhibited the highest recovery of TPC, ABTS, DPPH, and FRAP. This study emphasizes the feasibility and advantages of utilizing SPP and MLP as food ingredients for various food applications.