ABSTRACT
This study investigated the effects of ultra-high pressure (UHP) at different levels on the physicochemical properties, gelling properties, and in vitro digestion characteristics of myofibrillar protein (MP) in Tai Lake whitebait. The α-helix gradually unfolded and transformed into ß-sheet as the pressure increased from 0 to 400 MPa. In addition, the elastic modulus (G') and viscous modulus (G'') of the 400 MPa-treated MP samples increased by 4.8 and 3.8 times, respectively, compared with the control group. The gel properties of the MP also increased significantly after UHP treatment, e.g., the gel strength increased by a 4.8-fold when the pressure reached 400 Mpa, compared with the control group. The results of in vitro simulated digestion showed that the 400 MPa-treated MP gel samples showed a 1.8-fold increase in digestibility and a 69.6 % decrease in digestible particle size compared with the control group.
ABSTRACT
This study aimed to investigate the effects of high-intensity ultrasound treatment on the functional properties and emulsion stability of Neosalanx taihuensis myofibrillar protein (MP). The results showed that the carbonyl groups, emulsification properties, intrinsic fluorescence intensity, and surface hydrophobicity of the ultrasound treated MP solution were increased compared to the MP without ultrasound treatment. The results of secondary structure showed that the ultrasound treatment could cause a huge increase of ß-sheet and a decline of α-helix of MP, indicating that ultrasound induced molecular unfolding and stretching. Moreover, ultrasound reduced the content of total sulfhydryl and led to a certain degree of MP cross-linking. The microscopic morphology of MP emulsion indicated that the emulsion droplet decreased with the increase of ultrasound power. In addition, ultrasound could also increase the storage modulus of the MP emulsion. The results for the lipid oxidation products indicated that ultrasound significantly improved the oxidative stability of N. taihuensis MP emulsions. This study offers an important reference theoretically for the ultrasound modification of aquatic proteins and the future development of N. taihuensis deep-processed products represented by surimi.
