• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.1
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• pp.41-51
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• 1987

This study was carried out to prepare powdered smoked-dried mackerel which can be used as a soup base, and to examine storage stability and the taste compounds of Products. Raw mackerel are filleted, toiled for 10 minutes and pressed to remove lipids, and then soaked in extract solution of skipjack meat. This soaked mackerel are smoked 3 times to $10-12\%$ moisture content at $80^{\circ}C$ for 8 hours. And the smoked-dried mackerel were pulverized to 50 mesh. Finally, the powdered smoked-dried mackerel were packed in a laminated film $bag(PET/Al\;foil/CPP:\;5{\mu}m/15{\mu}m/70{\mu}m,\;15\times17cm)$ with air(product C), nitrogen(product N) and oxygen absorber(product O), and then stored at room temperature for 100 days. The moisture and crude lipid content of powdered smoked-dried mackerel was $11.3-12.3\%,\;12\%$, respectively, and water activity is 0.52-0.56. And these values showed little changes during storage. The pH, VBN and amino nitrogen content increased slowly during storage. Hydrophilic and lipophilic brown pigment formation showed a tendency of increase in product(C) and showed little change in product(N) and (O). The TBA value, peroxide value and carbonyl value of product(N) and (O) were lower than those of product (C). The major fatty acids of products were 16:0, 18:1, 22:6, 18:0 and 20:5, and polyenoic acids decreased, while saturated and monoenoic acids increased during processing and storage of products. The IMP content in products were 420.2-454.2 mg/100 g and decreased slightly with storage period. And major non-volatile organic acids in products were lactic acid, succinic acid and $\alpha-ketoglutaric$ acid. In free amino acids and related compounds, major ones are histidine, alanine, hydroxyproline, lysine, glutamic acid and anserine, which occupied $80.8\%$ of total free amino acids. The taste compounds of powdered smoked-dried mackerel were free amino acids and related compounds (1,279.4 mg/100 g), non-volatile organic acids(948.1 mg/100 g), nucleotides and their related compounds (672.8 mg/100 g), total creatinine(430.4 ntg/100 g), tetaine(86.6 mg/100 g) and small amount of TMAO. The extraction condition of powdered smoked-dried mackerel in preparing soup stock is appropriate at $100^{\circ}C$ for 1 minute. Judging from the results of taste and sensory evaluation, it is concluded that the powdered smoked-dried mackerel can be used as natural flavoring substance in preparing soups and broth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.275-284
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• 1984

In order to study the flavor quality of Chungkookjang, the changes in nitrogenous compounds, nucleotides and their related compounds, free amino acids, amino acid composition and fatty acids were analysed during Chungkookjang Koji fermentation. Koji was prepared with Bacillus natto isolated from Japanese natto. Insoluble nitrogenous was rapidly decreased, whereas PAA (peptide, amino, ammonia) nitrogen were slightly increased during the fermentation of Chungkookjang Koji. The content of extracted nitrogen and free amino acid nitrogen were rapidly increased until 48 hours fermentation of Chungkookjang Koji and then decreased. The contents of ADP, ATP, AMP and inosine in raw soybean were abundant. The contents of ADP, ATP and AMP were decreased while inosine and hypoxanthine were increased during the fermentation of Chungkookjang Koji. The free amino acids analyzed in this experiment were not changed in composition but changed in amounts during the fermentation of Chungkookjang Koji. The contents of alanine, valine, isoleucine and phenylalanine were continually increased during the fermentation of Chungkookjang Koji. The contents of lysine, histidine, arginine, glutamic acid, glycine, methionine and tyrosine were increased until 48 hours fermentation and then decreased gradually. The increase in the contents of aspartic acid, threonine, serine, proline and cystine were fluctuated. In raw soybean, amino acid composition such as glutamic acid, serine and proline were dominant amino acid and amounts those were 63.8% of the total amino acids. The contents of aspartic acid, proline, glycine, alanine, cystine, leucine and tyrosine were continually decreased during the fermentation of Chungkookjang Koji, arginine and methionine were increased until 48 hours fermentation of Chungkookjang Koji and then decreased gradually. The increase of threonine and serine were fluctuated. Eight kinds of fatty acids were detected from raw soybean, but 10 kinds of fatty acids detected from Chungkookjang Koji. Palmitic, oleic and linoleic acid were identified as the major fatty acid of raw soybean and Chungkookjang Koji, and amounts of those were estimated above 80% of the total fatty acids.