Preparation of Cassia Bean Gum/Soy Protein Isolate Composite Matrix Emulsion Gel and Its Effect on the Stability of Meat Sausage

Abstract

The use of plant-derived emulsified gel systems as fat substitutes for meat products has always been an important direction in the development of healthy foods. In this study, a composite matrix emulsion gel was prepared with soy protein isolate (SPI) and different concentrations of cassia bean gum (CG), and then the selected emulsion gel was applied to meat sausage as a fat substitute to explore its stability. Our results showed that the hardness, chewiness, viscosity, shear stress, and G' and G″ moduli of the emulsion gel increased considerably with the cassia bean gum concentration, the thickness of the emulsion gel increased, and the pore size decreased. The gel strength of the 1.75% CG/SPI emulsion gel was the highest, which was 586.91 g. The elasticity was 0.94 mm, the masticability was 452.94 mJ, and the water-holding capacity (WHC) was 98.45%. Then, the 1.75% CG/SPI emulsion gel obtained via screening was applied as a fat substitute in meat sausage. With an increase in the substitution amount, the cooking loss, emulsification stability, pH, color difference, texture, and antioxidant activity of the meat sausage before and after freezing and thawing increased first and then decreased. The indexes of meat sausage with 50% fat replacement were not considerably different from those of full-fat meat sausage. This study can provide a theoretical basis for the application of plant-derived emulsified gel systems as fat substitutes in meat sausage.

Keywords: cassia bean gum; composite matrix emulsion gel; fat substitute; freeze–thaw stability; meat and sausage.

Figure 1

Rheological characteristics of emulsion gels with different concentrations of cassia bean gum. Effects of cassia bean gum on the viscosity (A), frequency scan (B), and temperature scan (C). Data are expressed as the mean ± standard deviation. SPI/CG 0%: soy protein isolate, no cassia bean gum added; SPI/CG 0.85%: SPI + 0.85% cassia bean gum; SPI/CG 1.15%: SPI + 1.15% cassia bean gum; SPI/CG 1.45%: SPI + 1.45% cassia bean gum; SPI/CG 1.75%: SPI + 1.75% cassia bean gum; SPI/CG 2%: SPI + 2% cassia bean gum. Different letters indicate significant differences in the data (p < 0.05).

Figure 2

Effects of different concentrations of cassia bean gum on the water holding capacity and strength of emulsion gel. SPI/CG 0%: soy protein isolate, no cassia bean gum added; SPI/CG 0.85%: SPI + 0.85% cassia bean gum; SPI/CG 1.15%: SPI + 1.15% cassia bean gum; SPI/CG 1.45%: SPI + 1.45% cassia bean gum; SPI/CG 1.75%: SPI + 1.75% cassia bean gum; SPI/CG 2%: SPI + 2% cassia bean gum. Different letters indicate significant differences in the data (p < 0.05).

Figure 3

The appearance and scanning electron microscopy (SEM) images of emulsion gels with different concentrations of cassia bean gum. (a) SPI/CG 0%: soy protein isolate, no cassia bean gum added, (b) SPI/CG 0.85%: SPI + 0.85% cassia bean gum, (c) SPI/CG 1.15%: SPI + 1.15% cassia bean gum, (d) SPI/CG 1.45%: SPI + 1.45% cassia bean gum, (e) SPI/CG 1.75%: SPI + 1.75% cassia bean gum, and (f) SPI/CG 2%: SPI + 2% cassia bean gum.

Figure 4

FTIR spectra of emulsion gels with different concentrations of cassia bean gum. SPI: pure soy protein isolate solution; SPI/CG 0%: soy protein isolate, no added cassia bean gum; SPI/CG 0.85%: SPI + 0.85% cassia bean gum; SPI/CG 1.15%: SPI + 1.15% cassia bean gum; SPI/CG 1.45%: SPI + 1.45% cassia bean gum; SPI/CG 1.75%: SPI + 1.75% cassia bean gum; SPI/CG 2%: SPI + 2% cassia bean gum.

Figure 5

Effect of different concentrations of cassia bean gum on the thermal properties (DSC) of emulsion gels. SPI/CG0%: soy protein isolate, no cassia bean gum added; SPI/CG 0.85%: SPI + 0.85% cassia bean gum; SPI/CG 1.15%: SPI + 1.15% cassia bean gum; SPI/CG 1.45%: SPI + 1.45% cassia bean gum; SPI/CG 1.75%: SPI + 1.75% cassia bean gum; SPI/CG 2%: SPI + 2% cassia bean gum.

Figure 6

DPPH (A) and ABTS (B) free radical clearance of meat sausage during storage with different fat replacement amounts. C stands for (emulsion gel 1.75% CG/SPI) minced sausage with 0% fat replacement; S1 represents (emulsion gel 1.75% CG/SPI) meat sausage with 25% fat replacement; S2 stands for (emulsion gel 1.75% CG/SPI) minced sausage with 50% fat replacement; S3 stands for (emulsion gel 1.75% CG/SPI) minced meat with 75% fat replacement; S4 stands for (emulsion gel 1.75% CG/SPI) meat sausage with 100% fat replacement. Different letters indicate significant differences in the data (p < 0.05).