Effect of Drying on Creatine/Creatinine Ratios and Subsequent Taste of Herring (Clupea pallasii) Fillet

This study was conducted to investigate the effect of drying time on creatine/creatinine ratios, and subsequently taste of herring fillet. Creatine and creatinine contents were quantified during drying of herring fillet by hydrophilic interaction liquid chromatography (HILIC) and their effect on sensory perception was determined. Results showed that creatine content decreased significantly (p < 0.05), while creatinine content increased during the drying period. Creatinine/creatine ratio of herring fillet increased significantly (p < 0.05) up to the eighth day of drying and plateaued out thereafter. Sensory evaluation revealed that addition of a mixture of creatine and creatinine (at the ratio between 95:5 and 75:25) to the Japanese noodle soup resulted in optimum flavor enhancement of soup characteristics such as thickness, mouthfulness and continuity. These results suggest that for dried herring fillet, optimum creatinine/creatine ratios are reached after 10 days of drying.