Physicochemical and emulsifying properties of mung bean protein isolate as influenced by succinylation

Abstract

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.

Functional Properties of Rye Prolamin (Secalin) and Their Improvement by Protein Lipophilization through Capric Acid Covalent Binding

“…Therefore, it is conceivable to assume that the lipophilization shifted the isoelectric point of SCL to a lower pH value, most probably because of the reduction of free amino groups after reaction with the fatty acid. Similar effects of acylation were reported in mung bean [ 31 ] and soy proteins [ 32 ]. Figure 3 B shows the effect of high NaCl concentrations on SCL solubility.…”

Whole Wheat Crackers Fortified with Mixed Shrimp Oil and Tea Seed Oil Microcapsules Prepared from Mung Bean Protein Isolate and Sodium Alginate

“…At neutral pH used for emulsion preparation, proteins become mostly negatively charged since the pH is higher than pI. Mung bean protein was reported to have a pI of 5 [ 52 ]. Overall, higher values of ζ potential signify higher stability of the microcapsules due to increased electrostatic repulsions among the particles, leading to less agglomeration or flocculation of the powders [ 3 ].…”

Modification of pulse proteins for improved functionality and flavor profile: A comprehensive review

“…Interestingly, numerous conflicting literatures can be found on emulsification and foaming properties of acylated proteins. An improvement in emulsification and foaming properties was achieved after acylation for cowpea protein (Mune Mune et al., 2011), mung bean protein (Charoensuk et al., 2018), and Bambara groundnut (Lawal et al., 2007); yet adverse impacts on their activity or stability were also revealed in other proteins (Dua et al., 1996; Miedzianka et al., 2012; Mohamed et al., 2009). The justification for individual conclusion is likewise not quite conclusive and sometimes even antithetical in the activity or stability aspects, which manifests that the effects of acylation are somewhat uncertain and may be variable.…”

“…It has been postulated that accompanying by net charge increment and structural unfolding of a protein, the buried hydrophobic residues certainly expose to the solution, and hence the hydrophilic‒hydrophobic balance, in essence, is ultimately responsible for their alternations (Dua et al., 1996; Lawal et al., 2007; Sosulski & Fleming, 1977; Yin et al., 2010). Hence, it can be inferred that the degree of acylation, anhydride to protein ration, and protein type/composition and structure would also contribute to the final functionalities (Achouri & Zhang, 2001; Charoensuk et al., 2018; Ponnampalam et al., 1988; Yin et al., 2010).…”