Ovarian fullness affects biochemical composition and nutritional quality of female swimming crab Portunus trituberculatus

Ovary is an important edible component of female crabs in many countries, and ovarian fullness (maturity) had become an important quality indicator used for crab marketing. Adult females Portunus trituberculatus are typically divided into four grades (Grade I - IV) based on ovarian fullness in the carapace during the marketing. This study investigated the chemical composition and nutritional quality of market size female P. trituberculatus. The gonadosomatic index (GSI), hepatosomatic index (HSI) and total edible yield (TEY) showed a stepwise increase from Grade I to IV (P < 0.05). Crude protein and total lipid content in both ovaries and muscle significantly increased with fullness, where Grade II - IV had significantly higher lipid contents in the hepatopancreas compared to Grade I. Redness (a*) of carapace and ovaries was consistent with the total camtenoid contents in tissues. Sigma MUFA in both ovaries and muscle increased with crab grade, while Sigma PUFA in ovaries and muscle, as well as Sigma MUFA in the hepatopancreas decreased. For most amino acids in ovaries and muscle were also found to increase with grade. Higher-graded females generally had higher TEY, color parameters and better nutritional quality in edible tissues than the Grade I and II, which appears related to their different ovary stages of P. trituberculatus.