Abstract:
The stability of protein emulsion gels is influenced by multiple factors, such as protein concentration, oil volume fraction, and ionic strength, limiting the widespread application of emulsion gels.In this study, emulsion gels were prepared using soy protein isolate (SPI) and soybean oil (SO) to investigate the effects of SO and NaCl addition on the stability of emulsion gels. Changes in textural properties, gel strength, water holding capacity, oil holding capacity, moisture distribution, rheological properties, microstructure, protein secondary structure, and intermolecular forces were examined, and the emulsion gels were applied to soy protein-based vegetarian luncheon meat. The results showed that appropriate amounts of Na
+ and soybean oil significantly enhanced the stability of SPI emulsion gels enriched with soybean oil. In particular, with the addition of 30% SO and 0.434 mol/L Na
+, the gels exhibited optimal water holding capacity, oil holding capacity (92.92%, 96.47%), springiness (0.90), and cohesiveness (0.90) (
P<0.05). The protein secondary structure shifted from
α-helix to
β-sheet. SPI, SO, and Na
+ were pretreated to prepare emulsion gels, which were subsequently incorporated into soy protein-based vegetarian luncheon meat. The pretreated vegetarian luncheon meat exhibited a smooth surface, and its water holding capacity, oil holding capacity and springiness to those of the control. This study provides theoretical insights for enhancing the stability and gel strength of high-concentration protein-oil emulsion gels and emulsion droplet aggregation-type gels, facilitating their application in soy protein-based vegetarian meat product development.