The application of mung bean protein in foods is limited due to its poor functionality. Acylation with succinic anhydride could be used to improve the functionalities of protein. In this study, the influence of the weight ratio of succinic anhydride to protein (0–0.10) on the degree of N-acylation, physicochemical properties and protein functionalities including emulsifying properties of mung bean protein isolates (MPI) were investigated. The extent of N-acylation of MPI increased as the succinic anhydride:protein ratio increased, while the ζ-potential at neutral pH decreased. In addition, succinylation had an impact on the average particle size of MPI depending on the succinic anhydride:protein ratio. Succinylation had no impact on the total and exposed free sulfhydryl groups. Moreover, the isoelectric point (pI) of the succinylated proteins shifted from pH 5 to lower pH. Succinylation increased the emulsifying activity index (EAI), while the impact on the emulsion stability index depended on the succinic anhydride:protein ratio. Thus, succinylation at low succinic anhydride:protein ratio can alter mung bean protein charge and affect physicochemical and functional properties especially emulsifying properties that could be used to increase its utilization.

The influence of alcohols with different alkyl chain length (methanol, ethanol and propanol) on the physicochemical properties (turbidity, surface hydrophobicity, exposed and total free sulfhydryl groups, denaturation temperature; T_m) of pasteurized liquid egg white (PLEW), including gel properties (gel hardness and expressible liquid) and microstructure of heat-induced PLEW gel prepared at 75°C were studied. The results showed that alkyl chain length of alcohol and alcohol concentration had no impact on the total free sulfhydryl groups, but significantly increased the turbidity, surface hydrophobicity, exposed free sulfhydryl groups, gel hardness and expressible water. Increase the alkyl chain length of alcohol also significantly decreased the T_m and the total enthalpy change during heat-induced gelation of PLEW. Addition of 5% alcohol altered the microstructure of the PLEW gels in an alkyl chain length dependent manner.

The aim of this study was to compare the changes in the epaxial muscle proteins of Asian seabass at two different postmortem durations. The epaxial muscles of Asian seabass were collected 1 h or 24 h postmortem (PM). Whole, ungutted fish were stored in an ice box, with the ice refilled every two hours. The results show significant increases in the MFI values and the contents of solubilized sarcoplasmic proteins, with a molecular weight of proteins of 47 kDa in the 24 h PM samples (p < 0.05). Myofibrillar and alkaline-soluble proteins in the epaxial muscle remained intact 24 h postmortem. Compared with the 1 h PM samples, the 24 h PM meat exhibited lower degrees of expressible water and hardness (p < 0.05), indicating superior water-holding capacity and meat tenderness. However, no differences in springiness or cohesiveness of the cooked meat were observed. Free L-glutamic acid, known as an umami-tasting amino acid, was significantly increased upon the extension of postmortem duration, and its level was above the taste threshold concentration. Overall, the findings indicated that the 24 h PM epaxial muscle of Asian seabass exhibited superior technological properties, along with higher contents of taste-related amino acids.