Adsorption mechanism of key off-odor compounds of oyster peptide by V-type starch in the solid-phase environment.

V-type starch was employed to adsorb key off-odors (heptanal and 1-octen-3-ol) of oyster peptide (OP), and the adsorption mechanism was investigated. The off-odor content was quantified using gas chromatography (GC), and the successful inclusion complexes (ICs) between the key off-odors of OP and V-type starches were detected by X-ray diffraction, differential scanning calorimetry, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy. In FTIR spectra, the appearance of new peaks and the shifts of characteristic peaks in ICs indicated the successful formation of ICs between V-type starches and heptanal or 1-octen-3-ol. The results of thermodynamic analysis showed that the endothermic peaks of ICs in the range of 113-116 °C corresponded to the formation of V-type II complexes. The GC results suggested that V- and V-type starches exhibited selective adsorption of heptanal and 1-octen-3-ol, respectively, which was attributed to the size compatibility between starches and guest molecules. Furthermore, the correlation analysis exhibited that the encapsulation efficiency and loading efficiency of V-type starches for heptanal and 1-octen-3-ol were correlated with the enthalpy, short-range order degree and relative crystallinity. The research findings demonstrate the good adsorption effects of V-type starches on characteristic off-odors of OP, which could effectively improve the flavor of OP.