Effects of phosphorylated ovalbumin on the quality of pork myofibrillar protein gel: an insight into gelling and physicochemical properties
Zhihui Yu, Yating Gao, Meng Wu, Chaofan Zhao, Xiubin Liu, Xiaoyu Zhang, Lixin Zhang, Yisheng Chen
Abstract
This study aimed to investigate the effects of phosphorylated-ovalbumin (P-OVA) at different concentrations (0.5% and 1.0%) on the gel properties of pork myofibrillar protein (MP). The results showed that the textural properties such as gel hardness, cohesiveness, springiness and chewiness were improved with P-OVA addition at 0.5%. The water holding capacity (up to 75.89%) and gel strength (up to 168.56 g·mm) of MP gel were markedly increased after P-OVA addition. The absolute value of zeta potential reached 13.85 mV and maximum hydrophobicity (15.2 μg) resulted from the addition of 0.5% P-OVA. The storage modulus (G’) and loss modulus (G’’) of MP gel were significantly increased from 50°C, and the G’ and G’’ significantly increased after 1.0% P-OVA addition, evidencing that the cross-linking effect of MP protein gel was enhanced. In addition, the P-OVA addition improved the structure of MP gel protein by reducing the α-helix, while increasing the β-sheet and the r-value (the ratio between two ultraviolet second-derivative peak-to-trough distances), which further promoted the uniform and compact gel network structure. This work demonstrated that P-OVA is a highly effective modifier that significantly improves the quality of MP gel. From a view of practice, 0.5% P-OVA is the optimal addition amount.