Improvement of oxidized myofibrillar protein gel properties by black rice extract

Abstract

In order to investigate the effects of black rice extract (BE) on the composition of oxidized myofibrillar protein (MP) gel, different concentrations of BE (0, 10, 20, 50 mg g−1) were analyzed experimentally. Results revealed that the addition of small doses of BE significantly inhibited the formation of carbonyl groups in oxidized MP, and improved surface hydrophobicity and gel water holding capacity. Additionally, 10 and 20 mg g−1 BE increased the ordered structure of oxidized MP. Furthermore, dynamic rheometer results showed a significant increase in the storage modulus (G') of oxidized MP with 10 and 20 mg g−1 BE during heating. Scanning Electron Microscopy (SEM) showed that MP formed a denser network structure with addition of 10 and 20 mg g−1 BE. Low-Field Nuclear Magnetic Resonance (LF-NMR) and magnetic resonance imaging (MRI) showed that there is a significant increase in immobile water in MP gel and a decrease in free water within the 20 mg g−1 BE group. In conclusion, 20 mg g−1 supplemented BE significantly improved the structure order and hardness of oxidized MP gel, increased its structure density and water holding capacity, and it provides a theoretical basis for the application of antioxidants in meat products.

Keywords

• Black rice extract
• Myofibrillar protein
• Oxidation
• Physicochemical properties
• Gel properties