Gelling properties of myofibrillar protein from abalone (Haliotis Discus Hannai Ino) muscle

Texture of muscle food is dependent on the gelation properties of myofibrillar protein. Defining the performance of myofibrillar protein during gelation is beneficial for maintaining quality and developing muscle food. The myofibrillar protein from abalone muscle (AMP) was extracted and the gel-forming ability was investigated. The lowest protein solubility of AMP in distilled water was obtained at pH 5.5, but shifted to a lower pH value by ionic strength. The breaking force and deformation of AMP gel formed at pH 7.0 were 48.00g and 27.70mm, respectively, but they could not be detected at pH 5.0 and pH 5.5 due to the low gel-forming ability. Scanning electron microscopy data showed that a coarse and disorder gel containing clusters of agglomerates was observed at pH 5.0 and pH 5.5, but gradual compact network structure was observed in the gel formed at increasing pH. The glass transition temperature (Tg) of AMP gel formed at pH 5.5 was higher than that of AMP, and the Tg of AMP gel was increased with increasing the pH of gel-forming solution. It was found that the unfolding of tertiary structure of AMP at pH 7.0 was easier than that at pH 5.5 through the result of infrared spectra. We therefore conclude that both the solubility and gel-forming ability of AMP are pH dependent.