Effects of citrus fibre and soybean protein isolate on heat‐induced pork myofibrillar protein gel properties under low‐sodium salt conditions
Yuxuan Shi, Mingwu Zang, Shouwei Wang, Bing Zhao, Chenchen Xu, Jing Bai, Yan Zhao, Xiaoling Qiao, Jiajia Wu
Abstract
Summary The aim of this study was to investigate the effect of the combination of citrus fibre (CF) and soy protein isolate (SPI) on pork myofibrillar protein (MP) gel properties under low‐sodium salt conditions during the heating process. The composite (with CF and SPI) and single (with 1% and 2% NaCl) MP gels properties were evaluated by colour, water holding capacity (WHC), gel strength, rheological properties, microstructure, secondary structure, and water state. The addition of 0.45% CF and 1.5% SPI significantly improved WHC and gel strength, as well as increased the values of G′ and G′′ ( P < 0.05). The microstructure indicated that the CF/SPI could decrease the water channels and form a denser structure through filling effects, which was also proved by the fast T 21 relaxation time. However, the addition of 0.9% CF and 3.0% SPI could inhibit the protein aggregation and disrupt the stable and homogeneous structure. The analysis of the secondary structure showed that the CF/SPI resulted in a lower α‐helix content and a higher β‐sheet content compared with MP gels. This study may provide some guidance for the use of CF/SPI to improve MP gel properties in low‐salt meat products.