Effects of drying on the volatile flavor compounds in the extracts from niboshi (soup stock)

Abstract

 Volatile flavor compounds (VOC) in niboshi, boiled and dried anchovy Engraulis japonicus, and its extracts were analyzed by SPME-GC/MS to investigate the effects of lipid oxidation during the drying process on the odor of niboshi and the soup stock extracted from it. The amount of VOC was higher in niboshi when lipid levels of the raw material, anchovy, were higher and it also increased with drying time of boiled anchovy. The VOC and thiobarbituric acid levels in the soup stocks extracted from niboshi containing high levels of VOC were high. It can thus be concluded that niboshi from fatty anchovy contains high levels of secondary products having an unpleasant odor which is generated from lipids during the drying process and the secondary products will adversely affect the flavor of soup stock. These results suggest that omitting the drying process could be effective for reducing the odor of fatty anchovy extracts.