Abstract:

A comparative study was conducted on muscle physical and chemical qualities of Polyodon spathula, the hybrid
sturgeon H. dauricus♀ × A. schrencki♂ and Aristichthys nobilis. The results showed that flesh content in A. nobilis was
significantly higher than in two other sturgeon species (P ＜ 0.05). The muscle protein content of P. spathula was not different
from that of the hybrid and A. nobilis (P ＞ 0.05), and we further found that the hybrid was significantly lower than A. nobilis
(P ＜ 0.05). Crude fat was significantly more abundant in P. spathula as compared to that of A. nobilis (P ＜ 0.05), although
both species showed no significant difference from hybrid sturgeon (P ＜ 0.05). A. nobilis contained significantly higher
amounts of ash than the other sturgeon species (P ＜ 0.05). The fatty acid profiles in these three fish species were found
to consist of three saturated fatty acids (SFAs) and six unsaturated fatty acids (UFAs), and the UFA content in hybrid
sturgeon was higher than in P. spathula and A. nobilis (P ＜ 0.05). The content of mono-unsaturated fatty acids (MUFAs) in P. spathula was significantly higher than in hybrid sturgeon and A. nobilis (P ＜ 0.05) and the contents of poly-unsaturated
fatty acids (PUFAs) were significantly different among the three species (P ＜ 0.05) and the decreasing order was
hybrid sturgeon ＞ P. spathula ＞ A. nobilis. Similarly, the contents of highly unsaturated fatty acids (HUFAs) were
significantly different among them (P ＜ 0.05), showing a decreasing order of A. nobilis ＞ hybrid sturgeon ＞
P. spathula. The atherogenic index (AI) in P. spathula was significantly lower than that observed for A. nobilis
(P ＜ 0.05), and the thrombosis index (TI) in P. spathula and hybrid sturgeon was significantly lower than that of A. nobilis
(P ＜ 0.05). The cooked meat yield of hybrid sturgeon was significantly lower than that of A. nobilis(P ＜ 0.05), whereas
the collagen content was significantly higher than that of A. nobilis(P ＜ 0.05). Both juice loss and water loss in P. spathula
were significantly lower than those of hybrid sturgeon and A. nobilis (P ＜ 0.05). Fat loss and muscle fiber diameter were
not significantly different between P. spathula and hybrid sturgeon (P ＞ 0.05), but fat loss in P. spathula and hybrid
sturgeon was significantly lower than in A. nobilis (P ＜ 0.05), while muscle fiber diameter was significantly higher than
that of A. nobilis (P ＜ 0.05). No significant difference in muscle hardness was found between P. spathula and A. nobilis
(P ＞ 0.05), but the values of both species were significantly lower than that of hybrid sturgeon (P ＜ 0.05); in addition,
adhesiveness, cohesiveness, resilience and shear force in hybrid sturgeon were significantly higher than those observed for
A. nobilis (P ＜ 0.05). Springiness in P. spathula was significantly higher than that of A. nobilis (P ＜ 0.05). Chewiness was
significantly different among the three species, and the descending order was hybrid sturgeon ＞ P. spathula ＞ A. nobilis.
The hardness of cooked meat from hybrid sturgeon was significantly higher than that of A. nobilis (P ＜ 0.05); as for
cohesiveness and resilience, P. spathula was significantly higher than hybrid sturgeon and A. nobilis (P ＜ 0.05). Springiness
in P. spathula was significantly higher than that found in A. nobilis (P ＜ 0.05). Gummines and chewiness in P. spathula
were significantly higher than those of A. nobilis (P ＜ 0.05). Shear force was significantly lower in P. spathula compared to
A. nobilis (P ＜ 0.05). Moreover, muscle tenderness of P. spathula was significantly lower than that of A. nobilis (P ＜ 0.05),
and hybrid sturgeon was in the middle. However, no significant differences in juiciness, greasiness or flavor were found
among the three species. In conclusion, the flavor and IT/AT in P. spathula are relatively better, similar to hybrid sturgeon,
indicating health benefits; the contents of protein and other nutrients such as HUPA in A. nobilis are higher or close to the
ideal patterns, suggesting its higher nutritional value and better tenderness.

Key words: Polyodon spathula, hybrid sturgeon, Aristichthys nobilis, meat quality