Abstract:Collichthys lucidus is an important raw material for surimi production. Well known as one of the effective cold sterilization methods, electron irradiation has been widely used in industrial food preservation, as well as in food quality improvement, food safety, and other allied fields in many countries. Some studies indicated that electron irradiation can change the conformation of surimi proteins, leading to protein denaturation, aggregation and gelation. Thus the quality of surimi gel will be improved by using electron beam irradiation pre-treatment. The purpose was to investigate the influence of electron beam irradiation on the smell of surimi gel. Using gas chromatography-mass spectrometry (GC-MS) and relatively odor activity value (ROAV), the effect of different electron beam dose on the volatile flavor components of Collichthys lucidus surimi gel was studied. The sensory evaluation in association with electronic nose was applied to confirm the optimal dose, which can effectively maintain the original flavor of surimi gel. The results showed that the fish smell of gel derived from surimi irradiated was slightly reduced, and a little bit of irradiation odor was presented in high-dose group (≥7kGy). Compared with the control and irradiation groups, the difference of linear discriminant analysis (LDA) by electronic nose was obvious. The overlap of LDA between groups of 3kGy and 5kGy showed these two groups had similar odor characteristics, so did groups of 7kGy and 9kGy. After dealing with different irradiation doses, the species of volatile flavor compound and the relative contents of hydrocarbons, aldehydes and ketones from surimi gel were increased. Decanal, 1-octen-3-ol, 3-methyl-butanal and 2,3-octanedione were the key odor compounds of surimi gel. There was little influence of electron beam irradiation with low-dose (less than or equal to 5kGy) on the key and modify odor compounds of surimi gel. When the irradiation dose was more than 7kGy, (Z)-2-nonenal, (Z)-2-decene aldehyde, 2-hexenal in the surimi gel became important flavor components, the contribution to the flavor of ethyl acetate and 2-ethyl-furan was significantly reduced, it was likely to be the leading cause of the irradiation odor. In conclusion, 3～5kGy of electron beam irradiation dose, the original flavor of Collichthys lucidus surimi gel can be effectively maintained, but high dose (more than or equal to 7kGy) of irradiation would cause the generation of special off-odor. The results can provide some theoretical basis for using electron beam irradiation pre-treatment to improve the quality of surimi gel.
