Effects of L-Arginine on Emulsifying Properties of Pork Sarcoplasmic Protein

The effects of different mass fractions of L-arginine (0.0%, 0.5%, 1.0%, and 1.5%) on the emulsifying characteristics of pork sarcoplasmic protein were studied. The findings indicated that addition of L-arginine (≥ 1%) significantly enhanced the emulsifying activity and emulsion stability of sarcoplasmic protein (P < 0.05) and decreased the particle size (D_4,3, D₅₀, and D₉₀) of sarcoplasmic protein-stabilized emulsion (P < 0.05). The Turbiscan stability index (TSI) decreased after addition of L-arginine. The results of interfacial rheology showed that L-arginine increased the oil-water interfacial tension. The results of surface hydrophobicity and ultraviolet (UV) absorption spectroscopy implied that L-arginine promoted the exposure of protein hydrophobic groups (tryptophan and tyrosine residues). Raman spectroscopy showed that L-arginine was beneficial for the secondary structure transformation of sarcoplasmic protein from α-helix to β-turn. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the basic composition of sarcoplasmic protein was not affected by L-arginine. In summary, L-arginine could significantly improve the emulsifying properties of sarcoplasmic protein by changing emulsion physicochemical properties, protein interfacial characteristics, and protein secondary and tertiary structures.