Abstract:

In this work, the binding abilities of four characteristic fishy volatile compounds (heptanal, octanal, nonanal,
and 1-octen-3-ol) to silver carp meat proteins (myofibrillar proteins, myosin, and actin) were studied by headspace solid
phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). Results indicated
that myosin, one of the major myofibrillar proteins, was the primary binding receptor of the volatiles. Based on the studies
of thermodynamic models (Scatchard equation and Klotz plot), the Gibb’s free energy (ΔG) of binding of myosin to the
four fishy volatiles studied were all below 0, indicating that the interactions are spontaneous. Compared with other linerchain
aldehydes (heptanal, octanal and nonanal), 1-octen-3-ol had more binding sites and higher binding constant to myosin
protein. Moreover, the binding affinity of myosin to linear-chain aldehydes decreased with the chain length of the aldehydes.
These results could provide theoretical basis for improving the existing rinsing method, aiming to achieve effective
deodorization of surimi.

Key words: fish protein, fishy volatiles, headspace solid phase microextraction, headspace concentration, binding sites, binding constants, free energy