Preparation of high internal phase emulsions based on pumpkin seed oil body and its physicochemical properties

Abstract

In this study, we successfully prepared high internal phase emulsions (HIPEs) with 78%–90% oil phase based on pumpkin seed oil bodies (PSOBs) extracted by neutral extraction at 2800×g to 31000×g. There were no effects on the protein compositions and contents of PSOBs by different centrifugal forces. PSOBs included oleosin (14.5 kDa) and extrinsic proteins (22 kDa, 27 kDa, 33 kDa, 45 kDa). The HIPE-PSOB with 78% oil phase had relatively spherical droplets, which was similar to the PSOB with 72% oil phase extracted at 1000×g, while 83%–90% of the oil phase displayed polygonal droplets. All HIPEs-PSOB had gel-like properties, and HIPEs-PSOB with a higher oil phase had a better storage modulus. With the increase in the oil phase, the particle sizes increased, and the gel network structure, viscoelasticity, freeze‒thaw stability and oxidation stability improved, while the thermal stability worsened. This study offers guidance for expanding the application of OBs in food.