Hye-Suk Kim

Improvement on Fish Odor of Extracts from Salmon Frame Soaked in Soybean Milk

For the use of extracts from salmon frame as a basic material of Gomtang-like products, various methods (soaking into soybean milk, adding anchovy, and adding spices) for masking fish odor into extracts from salmon frame were examined and the food component characteristics were also compared with commercial Gomtang. According to the results of volatile basic nitrogen, transmission at 660 ㎚ and sensory evaluation of extracts, soaking treatment, which is the soaking of salmon frame into soybean milk, was the most efficient method among the various methods for masking fish odor into extracts from salmon frame. There was no difference in the proximate composition between extracts from salmon frame soaked (FS) and unsoaked (C) into soybean milk. The FS was not detected in heavy metals, such as chromium, lead and cadmium. The taste value of FS (16.26) was higher than that of C and the major amino acids were glutamic acid and aspartic acid. Total amino acid content of FS (3.08 g/100 mL) was also higher than those of C (2.95 g/100 mL) and commercial Gomtang (1.70 g/100 mL), and the major amino acids were glycine, proline, glutamic acid and arginine. The calcium and phosphorus contents of FS/500 mL accounted for 21.7% and 18.5%, respectively, of the recommended daily allowance of mineral for adult.

Lowering the Bitterness of Enzymatic Hydrolysate Using Aminopeptidase-active Fractions from the Common Squid (Todarodes pacificus) Hepatopancreas

Aminopeptidase-active fractions from crude extract of the hepatopancreas of a common squid (Todarodes pacificus) were obtained using acetone (AC; 30-40%) and ammonium sulfate precipitation (AS; 60-70% saturation), anion exchange (AE-II; 0.2 M NaCl) and gel filtration chromatography (GF-I; 30-50 kDa), respectively. The debittering capacity of GF-I fraction based on the aminopeptidase activity (89.2 U/mg), recovery (56.6%) and sensory evaluation (1.0) was better than that of other fractions. Release of amino acids increased as incubation time was increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides, as revealed by reverse-phase HPLC profiles. Peaks 3, 5 and 6 showed the decreased area (%), whereas peaks 1, 2 and 4 showed the increased area. The GF-I fractions were found to be suitable for reducing bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.