High pressure and heat-induced potato protein nanocomplexes as carriers for curcumin: influence of pH and curcumin addition pathway

This study aimed to assess the potential of high hydrostatic pressure (HHP) and heat treatment (HT) in facilitating the formation of nanoassemblies of potato proteins (PPs) and curcumin to protect this sensitive bioactive compound. Curcumin was introduced into patatin-rich protein dispersions (4% wt/wt) according to two pathways: before (pathway 1) or after (pathway 2) HHP treatment (400 or 600 MPa for 8 hr at pH 6 and pH 7) or HT (55 °C for 5 min at pH 6) to optimize curcumin–protein complexation efficiency (CE). Treatments increased PP surface hydrophobicity which facilitated curcumin binding and protein aggregation, as confirmed by protein particle size increase. The highest CE was obtained with pathway 1 at 600 MPa pH 7, while HT limited curcumin complexation. Whatever the pathway, the antioxidant activity of the processed dispersions treated at 600 MPa for 8 hr or 55 °C for 5 min was increased compared to untreated ones and preserved after 10 days of storage at 4 °C. These nanocomplexes could potentially be applied in functional foods.