| Nutritional quality and sensory quality of different edible parts from cultured crocodile(Crocodylus siamensis) were evaluated in this study. And the functional properties of myofibrillar proteins were discussed.The meat quality of different edible parts of cultured Crocodylus Siamensis was evaluated from nutritional aspect, and compared with other common livestock and poultry. General nutrients of meat from torso, tail and legs, including moisture content, crude protein content, crude fat content and ash content, were tested according to national standards. The results showed that: the crude protein content in tail(20.25%) was higher than that of leg(18.70%) and torso(18.36%); the crude fat content(0.98%) was higher than leg’s(0.70%) but lower than torso’s(1.12%). Fatty acid composition was detected by GC-MS after fat extraction through acid hydrolysis and fast methylation. A total of 30 fatty acids were detected in tail meat, and the unsaturated fatty acid(UFA) ratio(68.22%) was significantly higher than that of body(66.66%) and leg(64.91%); total proportion of EPA and DHA was richer in leg meat(2.88%) than that of tail(2.22%)and body(1.42%). 17 kinds of amino acids were detected by automatic amino acid analyzer after acid hydrolysis, and Tryptophan was tested through fluorescence spectrophotometer after alkaline hydrolysis. The results showed that total amino acid(TAA) of tail, leg and torso were 70.47%, 72.17% and 72.58%; EAAI were 71.63, 74.37 and 79.62. Mineral composition, including K、Na、Ca、Mg、Mn、Fe、Zn、Cu elements, mainly detected by graphite furnace atomic absorption spectrometer. cultured Crocodylus siamensis meat is rich in Ca, Zn, Fe elements. These results indicate that cultured Crocodylus siamensis was a kind of meat with high nutritional value.The sensory quality of cultured Crocodylus siamensis was evaluated and analyzed through color, juiciness, tenderness and texture properties these four aspects. The color of meats was detected by color chromatic meter. It is found that difference of the color in different parts was significant. The color of tail meat is white and the tenderness is the best; the color of leg meat is red; and followed by poor torso meat. Juiciness was evaluated through water holding capacity(WHC) and cooking loss. WHC of tail meat was 84.01% and significant higher than that of torso(81.95%) and leg(80.79%). The cooking loss of tail was the lowest. The tenderness was evaluated by p H value, hydroxyproline content and Myofibrillar fragmentation index(MFI). The results showed that p H value of torso and tail were lower than that of leg, so the tail meat and torso meat were softer. Hydroxyproline content of tail meat was the lowest(tail 0.24%, leg 0.31%, torso 0.32%), so was the MFI value(tail 70.67, leg 66.73, torso 49.47). The texture properties were detected by texture analyzer. It is found that Texture profile analysis found that hardness, adhesiveness, chewiness and resilience presented a rule like: leg meat > tail meat > torso meat. Comprehensive the results of color, juiciness, tenderness and texture properties these four aspects: the white tail meat had the best juiciness and tenderness, the red leg meat was the second, the pink torso meat was the worst.Myofibrillar proteins in meat proteins played a key role of meat products processing. Therefore, the proteins composition of cultured crocodile(Crocodylus siamensis) were detected for chosing one of edible parts from crocodile,which had the highest content of myofibrillar proteins for further extraction. Molecular weight distribution of myofibrillar proteins was analyzed. And the effects of different external factors on solubilities, emulsifying properties and gel properties of myofibrillar protein had been detected after extraction. The results showed that: the myofibrillar proteins content in tail(7.95±0.12g/100 g, leg7.65±0.42 g/100 g, torso 6.87±0.28 g/100g) was the highest; the electrophoretic patterns indicated that myofibrillar proteins mainly contained myosin, paramyosin, actin, tropomyosin and troponin; Na Cl concentration, p H and temerprture had an extremely signi?cant effect on gel properties: At low ionic concentration, the solubilities and emulsifying properties were worst, the gel properties were better, and increased with the ionic concentration increasing except gel properties. And with increasing p H value, the solubilities increased first but decreased later and the emulsifying properties continued to slow down, and gel properties showed a trend of decline. The solubilities and the water-holding capacity(WHC) got the bottom at p H 5.5; With increasing temperature, the gel properties(texture properties) increased significantly, and the WHC decreased first but increased later.The meat quality of cultured Crocodylus siamensis was evaluated in this study. The torso meat had the highest flesh rate, but showed worse an sensory quality. The flesh rate of tail meat was lower than that of torso, but tail meat had the high quality in protein and sensory properties, and could be the material of meat products of Crocodylus siamensis. The flesh rate of leg meat was the lowest, but the red color and the good chewiness may be easily accepted by consumers. In order to get better texture quality and WHC, meat products of Crocodylus siamensis could be cooked at 0.2mol/L Na Cl(p H6.0~6.5) and 80℃ during developing. |
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