Studies on the Processing of Rapid- and low Salt-Fermented Liquefaction of Anchovy(Engrulis japonica) (II) - Changes in the Amino Acids from Oligopeptides during Fermentation -
In order to establish the processing conditions for salt-fermented liquefaction of anchovy(Engrulis japonica), changes in the amino acid composition from oligopeptides during fermentation periods were analyzed. Experimental sample A: chopped whole anchovy, adding 20% water, heating at 50℃ for 9 hrs and then adding 10% NaCl. Sample B: chopped whole anchovy, adding 20% water, heating at 50℃ for 9 hrs and then adding 13% NaCl. Sample C: chopped whole anchovy adding 13% NaCl. Sample D: whole anchovy adding 17% NaCl. The total amino acids from oligopeptides in fermented liquefaction of anchovy increased in early fermentation period and reached highest level, and then they declined irregularly during fermentation. Their maximum amounts were just after heating at 50℃ for 9 hrs in sample A, after 15 days in sample B, and after 60 days in samples C and D. The fermented liquefaction of anchovy extracts were rich in glutamic acid, aspartic acid, proline, glycine, alanine, lysine and valine. However, the contents of most amino acids fluctuated by the experimental specimens and fermenting periods. Among them glutamic acid was the most abundant amino acid which was occupied 0.6~27.7%(average 24.0%) in the content of total amino acids from oligopeptides. The contribution of the amino acid composition from oligopeptides to extractive nitrogen was occupying average 20.8 and 17.5% in rapid- and low salt-fermented liquefaction(sample A, B and C) and traditional fermented liquefaction(sample D), respectively.