Impact of breeding environments on the fatty acid composition of Rana chensinensis ovum from Changbai Mountain based on UPLC-Q/TOF-MS analysis

Rana chensinensis ovum (RCO), similar to fish roe, is a part of the gonads of Rana chensinensis and has become a premium delicacy due to its unique flavor and high nutritional value. The impact of breeding environments on the fatty acid content of RCO from various locations, primarily produced in Changbai Mountain, was explored in this study. RCO samples were collected from nine distinct regions that covered the primary production areas. Environmental factors such as altitude, longitude, latitude, average annual temperature, average annual ground temperature, annual precipitation, sunshine hours, soil top/substrate pH (T/S-pH-H2O), and soil top/substrate organic carbon content (T/S-OC) were evaluated. A UPLC-Q/TOF-MS-based method was used to determine the composition and distribution of fatty acids in RCO samples collected from different locations. Twenty-three fatty acid components, including DHA, EPA, DPA, ALA, C20:2, C20:3, C18:4, LA, C20:1, AA, C7:0, C10:1, C11:1, C16:2, C16:1, C16:0, OA, C18:0 C19:0, C23:1, C24:1, C22:0, and C17:1, were identified in RCO samples. Gray relational analysis (GRA) and Pearson correlation were employed to evaluate the influence of each environmental factor on fatty acid composition. Hierarchical cluster analysis (HCA), principal component analyses (PCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to classify RCO samples from different origins and analyze their similarities and differences. The results indicated that the habitat of Rana chensinensis can influence their nutritional value, as differences in fatty acid components were observed in RCO samples collected from different environments.