Changes in extractive components during processing of dried mullet [Mugil cephalus] roe

Four samples from different stages of the dried mullet roe processing were analyzed in detail for extractive components as well as proximate composition to correlate their changes with the formation of its characteristic flavor during the processing. The protein and lipid contents declined slightly during the processing, while the ash content increased considerably in the salting process. The extractive nitrogen increased continuously throughout the processing, but the increase in the sun-drying process was more pronounced than in the other processes. Among the changes in content of various nitrogenous and nonnitrogenous extractive con-stituents, those of the free amino acids were the most remarkable; most of them continued to increase during the processing, but the increasing rate was much higher in the sun-drying process than in the preceding processes as was the case for extractive nitrogen. The sum of free amino acid contents in the raw material was doubled in the final product. It is noteworthy that the increments of free alanine, glutamic acid, valine, glycine, arginine, and methionine, which have been reported to be taste-active in some seafoods, were prominent.