Pulsed electric field-assisted glycation of bovine serum albumin/starch conjugates improved their emulsifying properties

Abstract

In this study, pulsed electric field (PEF, at electric field strengths from 3.5 to 8.1 kV/cm, pulse duration (τ) = 50 μs) was used to assist the glycation between soluble potato starch and bovine serum albumin (BSA). Moreover, the physicochemical and stability of BSA/starch conjugates emulsions were characterized. Spectroscopic investigations (A420 and UV–Vis spectra) proved that PEF treatment (3.5–5.7 kV/cm) facilitated Maillard reaction between BSA and soluble starch. Moreover, the grafting degree (%) and the protein solubility of BSA/starch conjugates increased after PEF treatment but declined at higher electric field strengths. PEF treatment (at 3.5–5.7 kV/cm) decreased the particle sizes, surface hydrophobicity and fluorescence emission intensity of BSA/starch conjugates. Furthermore, emulsions stabilized by PEF-treated conjugates (at electric field strengths 3.5–5.7 kV/cm) exhibited smaller droplet sizes and higher adsorbed protein (AP%), indicating improved emulsion stability. Similarly, emulsions stabilized by PEF-induced conjugates (at electric field strengths 3.5–5.7 kV/cm) had better stability at pH = 4.6 and against different ionic strengths (150-300 mM NaCl). Differential scanning calorimetry (DSC) patterns showed that emulsions stabilized by PEF-treated conjugates had better freeze-thaw stability. In conclusion, PEF as a green technology could assist glycation and enhance the emulsifying properties of protein-polysaccharides conjugates. Industrial relevanceApplying green technologies in the food industry is critical for sustainable food production. As an eco-friendly food processing approach, PEF has been utilized in food industries to inactivate enzymes and microorganisms without affecting the nutritional quality of treated foodstuffs. Moreover, emulsions are widely applied in the food, drug delivery, and pharmaceutical industries. In our research, PEF could facilitate the Maillard reaction between soluble starch and BSA and improve the emulsifying properties of BSA/soluble starch conjugates. The results of this work could provide fundamental information on the mechanism of PEF-induced Maillard reaction and how PEF can improve the emulsifying properties of the conjugates. Thus, this work could help for increasing PEF applications in the food industries.