Minced Beef Meat Paste Characteristics: Gel Properties, Water Distribution, and Microstructures Regulated by Medium Molecular Mass of γ-Poly-Glutamic Acid

Abstract

The influences of various m-γ-PGA (0.08-0.20%, w/w) concentrations on the properties of minced beef meat paste in terms of rheological properties, texture, moisture distribution, and microstructures were evaluated. The results indicated that m-γ-PGA enhanced the water-holding capacity, gel strength, texture, and whiteness of the minced beef meat paste. Based on the microstructural results, m-γ-PGA helped form a more organized and compact gel, thereby limiting the migration of water through the gel matrix. In contrast to the control group, the water-holding property, gel strength, and whiteness of minced meat paste gels with m-γ-PGA content of 0.12% increased from 75.89%, 584.51 g·cm, and 61.83 to 79.91%, 780.87 g·cm, and 62.54, respectively (p < 0.05), exhibiting the highest water-holding property and gel strength. Thus, m-γ-PGA exhibits great potential for minced meat paste products as a healthy gel water retainer and enhancer in low-fat meat products.

Keywords: gel property; microstructure; minced beef meat paste; molecular weight; water-holding capacity; γ-poly-glutamic acid.

Figure 1

Moisturizing properties of γ-PGA degradation products. Different superscript letters (a–c) indicate significance (at α = 0.05 level); the same below.

Figure 2

Effect of different additions of m-γ-PGA (0.00, 0.08, 0.12, 0.16, and 0.20%) on the storage modulus (a) and tan δ (b) at different frequencies and storage modulus at different temperatures (c) of minced beef meat paste.

Figure 3

Effect of different additions of m-γ-PGA (0.00, 0.08, 0.12, 0.16, and 0.20%) on breaking force and deformation (a) and gel strength (b) of gels prepared from raw minced beef meat paste. Different superscript letters (a–d) indicate significance (at α = 0.05 level).

Figure 4

Effect of different additions of m-γ-PGA (0.00, 0.08, 0.12, 0.16, and 0.20%) on water-holding capacity and cooking loss of minced beef meat paste. Different superscript letters (a–c) indicate significance (at α = 0.05 level).

Figure 5

T₂ relaxation time curves (a), T₂ relaxation times (b), and T₂ percentage content (c) in minced beef meat paste gels with different levels of m-γ-PGA added. The red, yellow, green, blue, and purple curves in Figure 5a represent the T₂ relaxation time curves of meat gels with m-γ-PGA content of 0, 0.08, 0.12, 0.16, and 0.20%, respectively. Different superscript letters (a–d) in (b,c) indicate significance (at α = 0.05 level).

Figure 6

Microstructure of beef meat gels at m-γ-PGA concentrations of 0.00, 0.08, 0.12, 0.16, and 0.20% (a–e).

Figure 7

Principal component analysis (a) and Pearson’s correlation analysis (b). The arrows in (a) correspond to the loadings of the correlation indicators. The circle size and color gradient in (b) indicate the correlation coefficients (r-value), and the * and ** symbols in (b) represent significant correlation at the significance levels of 0.05 and 0.01, respectively.