Abstract:
The proximate compositions including protein, carbohydrate and lipid, amino acid composition and protein components in the different parts of Nanri abalone muscle were investigated. And, their microstructure structure, secondary structure and thermal properties were determined by scanning electron microscopy ( SEM) , fourier transform infrared spectroscopy ( FTIR) and differential scanning calorimetry ( DSC) , respectively. The composition, muscle tissue and thermal properties of pui-, joint-and skirt-part in Nanri abalone muscle were investigated.The results showed that the moisture content gradually increased from pui-muscle to skirt-muscle, but the contents of protein, carbohydrate and lipid were decreased. The amino acid compositions of pui-muscle were similar to those of joint-muscle.However, the glycine, proline and hydroxyproline that were characteristic to collagen were richer in skirt-muscle than other parts of abalone muscle. Based on electrophoresis analysis, it was suggested that the protein of pui-and joint-muscle was mainly composed of myosin heavy chain, paramyosin and actin, while collagen bands with the molecular weight of around 150 kDa were also found in the skirt muscle.However, the polysaccharides were combined with paramyosin and actin irrespective of abalone muscle parts.As indicated by SEM, the extent of compact fibril microstructure was gradually increased from pui-muscle to skirt-muscle. Amide III infrared band was not found in the FTIR of pui-and joint-abalone muscle, but was found in the skirt-muscle.Furthermore, one exothermic peak and three endothermic peaks of protein thermal transition were shown in the DSC thermograms of both pui-and joint-muscle, while only one endothermic peak of collagen in the skirt muscle. From above results, the carbohydrate content of pui-and joint-muscle was higher than skirt-muscle, with looser fibre structure and more complex composition.