Effects of Temporary Rearing on the Muscle Flavor Quality of Chinemys reevesii

Chinemys reevesii, a special economic aquaculture species in China, is valued highly for its medicinal and nutritional benefits. However, the muscle of farmed C. reevesii exhibits a strong off-flavor, resulting in poor flavor quality. To enhance the flavor quality of the C. reevesii meat, this study examined the volatile compounds in C. reevesii muscle by establishing identification methods for these volatile odor compounds and comparing the differences between the two aquaculture modes. It also explored the impact of fasting temporary rearing (60 days) on the flavor quality of the C. reevesii meat. The results indicated that a combination of direct solvent extraction-solvent-assisted flavor evaporation (DSE-SAFE), headspace-solid phase microextraction (HS-SPME), gas chromatography-mass spectrometry/olfactometry (GC-MS/O), and aroma recombination effectively simulated the odor profile of C. reevesii meat. The study identified the key volatile odor compounds in outdoor pond-cultivated C. reevesii meat (OP), including hexanal, heptanal, 1-octen-3-ol, octanal, nonanal, (E)-2-nonenal, decanal, (E)-2-decenal, (E,E)-2,4-decadienal, and dodecanal. In greenhouse-cultivated C. reevesii meat (GH), key volatile odor compounds were hexanal, hexanol, heptanal, 1-octen-3-ol, octanal, nonanal, (E)-2-nonenal, decanal, (E)-2-decenal, and dodecanal. The study found that appropriate fasting temporary rearing improved the odor quality of C. reevesii meat; OP temporary rearing for 40-50 days showed a significant reduction in greasy and musty odors. In GH, 40 days temporary rearing retained a fresh aroma while reducing the seaweed and fishy odors, achieving a flavor similar to OP. This study provides data support for C. reevesii meat processing and suggests a reference for applying temporary rearing to enhance the flavor quality of aquatic products.