Flavor Nucleotides and Volatile Flavor Compounds of Net-Cage Farmed Triploid Rainbow Trout in Qinghai Province

To investigate the flavor profile of triploid rainbow trout from Qinghai Province, high performance liquid chromatography (HPLC) and headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) were used to analyze the flavor compounds of fish cultured in net cages from Longyangxia, Gongboxia and Laxiwa. Results showed that the inosinic acid (IMP) content of farmed rainbow trout in Qinghai Province was 176~242 mg/100 g. The IMP content of rainbow trout in Gongboxia and Laxiwa was significantly higher than that in Longyangxia group (P<0.05). As for odor chemicals, a total of 69 volatile compounds were identified, 21 odor active compounds were screened by odor activity value (odor activity value, OAV) method. Nonanal, octanal, 2-nonenal, 1-octene-3-ol and hexanal contributed greatly to the typical smell of triploid rainbow trout with grassy, oily, floral and fishy characteristics. Volatile compounds content in the fillet of rainbow trout from Gongboxia and Laxiwa was relatively higher than those in Longyangxia group. In summary, triploid rainbow trout farmed in Qinghai Province obtained a high content of flavor nucleotides and was rich in volatile compounds. The rainbow trout farmed in Laxiwa and Gongboxia with high content of inosinic acid and volatile odor compounds showed similar flavor profile. Longyangxia cultured rainbow trout had high freshness, lower taste and odor intensity. The results would provide a theoretical basis for the analysis and regulation of fish flavor compounds in cultured triploid rainbow trout.