Revealing the synergistic effect of hydration and pulsed ultrasound on the emulsifying properties of silkworm pupa protein and its stabilized emulsion

Abstract

BACKGROUNDSilkworm (Bombyx moil L.) Pupa protein (SPP) is a high‐quality insect protein and is considered a sustainable alternative source for traditional animal food protein. However, the utilization of SPP is limited due to its low solubility and emulsifying ability. In this study, the synergistic effect of hydration and pulsed ultrasound on the physicochemical properties of SPP and SPP‐stabilized Pickering emulsions was evaluated.RESULTSPulsed ultrasound changed the particle size of SPP and its conformation. As the pulsed ultrasound increased from 0 to 5 s, the α‐helix and S—S contents of SPP decreased, whereas the β‐sheet and ‐SH contents increased, which in turn improved its solubility and amphiphilicity. As a result, the SPP treated by a combination of 12 h of hydration and 3 s of ultrasound exhibited a contact angle of 74.95°, hydrophobicity of 904.83, EAI of 6.66 m2/g, and ESI of 190.69 min. Compared with the combination of 1 h of hydration and 5 s of ultrasound, the combination of 12 h of hydration and 3 s of ultrasound exerted more soluble and hydrophobic SPP, while the EAI and ESI of the samples were higher. Notably, the ultrasound‐treated SPP can form a stable gel‐like emulsion (oil fraction ranging from 70% to 80%).CONCLUSIONThe combination of hydration and ultrasound can effectively improve the physicochemical characteristics of SPP as well as its emulsion stability. Sufficient hydration is a cost‐effective method for facilitating the modification of proteins by ultrasound treatment.This article is protected by copyright. All rights reserved.