Exploring the quality changes of carp roes: perspective from flavor characteristics and microstructure

Freshwater fish roes possess high nutritional value but exhibit limited industrial utilization due to their pronounced fishy flavor. This study aimed to investigate the improvement in fishy flavor and changes in the texture of carp roe under different heating conditions. Results demonstrated that increasing heating temperature and time significantly reduced fishy-flavored compounds (nonanal, (E, E)-2,4-nonadienal), as well as grassy and fruity compounds (hexanal, E-2-octenal) compared with fresh roe. Furthermore, fatty and fragrant compounds (2-nonen-1-ol, eugenol, 3,4-dimethoxy styrene and 2-pentyl furan) were generated, enriching the flavor profiles. Heating promoted the oxidation of unsaturated fatty acids to form aldehydes, ketones and alcohols. Odor activity value (OAV) analysis further identified eleven key aroma components that imparted a unique flavor to carp roe. Meanwhile, heating reduced the roe diameter and stabilized their morphology. It was also beneficial for suitable color, hardness and chewiness formation. Microstructural analysis revealed smoother cross-sections and denser reticulated pores in heat-treated roes. In conclusion, heating effectively improved the fishy flavor and had no significantly negative effect on texture, providing insights for industrial processing and utilization.