Characterizing and decoding the key odor compounds of Spirulina platensis at different processing stages by sensomics.

Processing is an indispensable technology in the preparation of Spirulina platensis (S. platensis). The key odorants in liquids, muds, and powders from S. platensis (NM and GZ) were characterized. A total of 90 odorants were identified and 41 odorants were sniffed with the flavor dilution (FD) factors ranging from 1 to 729. Among them, nonanal, decanal, d -limonene, β -cyclocitral, and β -ionone with FD factors ≥1 were detected in S. platensis during the whole processing stages. In addition, heptanal, (E , E)-2,4-nonadienal, trans -4,5-epoxy-(E)-2-decenal, 1-hepten-3-one, isophorone, 3-ethyl-2,5-dimethylpyrazine, and α -ionone exhibited higher odor activity values in powders; β -myrcene, methional, and S -methyl methanethiosulphonate were key odorants in muds; while trans -3-penten-2-ol was key odorant in liquids. Besides, the GZ-mud presented stronger earthy and fishy odor than NM - mud. S. platensis powders have the stronger grassy odor, roasted odor, and marine odor than S. platensis muds. Overall, drying process promotes the formation of aldehydes, heterocyclic compounds, and terpenoids. [Display omitted] • Aldehydes, pyrazines, and terpenoids in S. platensis powders increased during drying process. • S. platensis powders have the stronger grassy odor, roasted odor, and marine odor. • Acid and sulfides mainly imparted rancid and fishy odor to S. platensis muds. • GC-IMS distinguished S. platensis odor differences at different processing stages. [ABSTRACT FROM AUTHOR]