Changes in the Components and the odor of Sardine Extractives by Gamma-Irradiation

Abstract

The changes in undesirable odor, taste and microcomponents, when 80% ethanol extractives of sardine meat were irradiated from 0.5 to 2.5 kGy, were examined.
Results of the sensory evaluation by Scheffé's method (paired comparison) showed that the irradiation with 1.0 kGy was slightly weaker in fishy odor than other irradiation doses (Fig. 1). No significant difference of amino acid content (Table 1), nucleic content, crude protein and pH was found between unirradiated extractives and irradiated ones. C22:5 acid of fatty acids in the extractives decreased significantly by irradiation with a dose ofkGy (Table 2).
As an increase of irradiation dose, slight increases of acetaldehyde and propylaldehyde in carbonyl compounds (Table 3), and volatile sulfur compounds, hydrogen sulfide and dimethylsulfide in the extractives were observed.
However, the correlation between reduction of odor and changes in the microcomponents in the extractives by irradiation was not clarified from these results.