Mechanism Involved in the Formation of Characteristic Taste and Flavor during the Production of Dried Herring (Clupea pallasii) Fillet

The objective of this study was to identify the mechanisms responsible for the characteristic taste and flavor of dried herring fillet (DHF, migaki-nishin in Japanese). Dialyzed water-soluble fractions (DWSF) obtained from herring fillet were dried for 4 days, mixed with fatty acids, and the reaction products were evaluated for their effects on sensory perception. To clarify the mechanisms of in situ chemical changes in DHF lipid, ESI-MS analysis was done using a phosphatidylcholine probe. Sensory evaluation revealed that addition of the reaction products of DWSF with docosahexaenoic acid to Japanese noodle soup significantly (P < 0.05) enhanced soup flavor characteristics, such as thickness, mouthfulness, and continuity, compared to the reaction products of DWSF with linoleic acid or capric acid. ESI-MS analyses showed that lyso-derivatives were the most abundant compounds in the lipid fraction of DHF. A small amount of lipid oxidation products and their reaction products were also observed in DHF. This study demonstrated that during the drying period, partial hydrolysis of lipids released free fatty acids. These free fatty acids, or their oxidation products, might react with amino acid-related compounds to generate the characteristic taste and flavor of DHF.