Study On Calipash Features Of The Same Size Chinese Trionyx Sinensis Under Different Breeding Modes

Chinese Trionyx sinensis is one of the specific high economic value aquatic product inChina. Domestic and foreign consumers like it because of its unique flavor, high edible andmedicinal value. This paper was intended to explore a method of identifying Chinese Trionyxsinensis of different breeding modes, to find the main influence of different breeding modeson the quality of calipash, so we can provide data support for the processing.Greenhouse Trionyx sinensis, two-stage breeding Trionyx sinensis and wild Trionyxsinensis were analyzed for appearance, biological characteristics, nutrients and histologicalindicators. Compared the textural quality by the texture tests and sensory evaluation.Revealed the main factors affecting the texture of calipash. According to biologicalcharacteristics investigation result, not only quality proportion but also width, C>B>A.Compare the color of Calipash. The results showed that, overall the three are green-yellow(L*>0, a*<0, b*>0), and there was a notable difference of yellowness and brightness amongthe three. The L*value of B is close to C, and is1.5times as high as A. The b*value of C is2times higher than B, and17times higher than A. By comparing the basic nutrition elementsdiscovered the fat content B and C was significantly lower than A, and the order of crudeprotein content is C> B>A.By using high performance liquid chromatography(HPLC) method, the composition ofamino acids, the total amino acid content and crude protein content are analyzed. Resultsshows that major amino acids content in Calipash is similar among A, B, and C, with theexception of hydroxyproline(7.92%) and proline(10.08%) in wild sinensis, which doubled thevalues of other two. The content of hydroxyproline and proline could be used as a reliableindicator of different breeding methods. By SDS-PAGE analysis, no significant different wasdetected in protein size as major molecular weight in three groups are10.1,11.2and12.7KDrespectively.Tissue textural difference of Calipash was then analyzed using paraffin section. It isobvious elastic fiber and collagenous fiber in the middle layer of Calipash have very differentcurvature in three groups as group A curve the most. Group C has the largest fiber diagram of155.40μm (~5times of A and~2times of B). On the contrary, group A has the highest fiberdensity of1106.01N/mm2(~2times of B and~11times of C). The three values are highlycorrelated to reveal the fact that group C has most compact fiber structure and group A has theleast.Textural analysis was conducted on texture analyzer, and Calipash from three groupsshows very different hardness. Group C has approximately2times hardness of group A and1.67times of B (P<0.01). For gumminess value, group C is90%higher than A and66%higher than B (P<0.01). Through correlation analysis, it shows that hydroxyproline content,water content and fiber density have most significant impact on the hardness and gumminess.Sensory evaluation further confirmed the prediction. Hardness, gumminess andchewability is significantly different among three groups. Three variables have R=0.989,0.999and0.996between sensory and textural tests.