• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.3
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• pp.278-282
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• 2006

The powdered boil-dried oyster (C), the powdered smoke-dried oyster (OS-1) and the powdered smoke-dried oyster scrap (OS-2) were examined for their taste-active components, quality characteristics for potential utilization as a natural flavoring substance. The free amino acid level of OS-l and OS-2 were 395.6 mg/100 g and 551.5 mg/100 g, respectively, and that of betaine of OS-1 and OS-2 were 164.6 mg/100 g and 214.9 mg/100 g, respectively. The contents of inorganic ions were rich in Na, K, P, Ca and Mg in that order. Major free amino acids were taurine, glutamic acid, proline, alanine and glycine. The extract condition of the OS-1 and OS-2 the instant soup was the most appropriate at $98^{\circ}C$ for 1-5 min. The hot water extract of OS-1 and OS-2 with additives such as salt, sugar, pepper and onion powder had a good organoleptic qualities compared with the conventional flavoring substances in a local market. We conclude that powdered smoke-dried oyster and its scrap can be commercialized.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.733-739
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• 2014

To develop an effective use for poor-quality individually quick-frozen (IQF) oysters Crassostrea gigas stored for a long period, the extract conditions, quality characteristics, and optimum reaction flavoring (RF) conditions of a complex extract from these IQF oysters were investigated. The moisture, pH, and volatile basic nitrogen contents of IQF oysters stored for 18 months (18M-IQFO) were 77.9%, 6.32, and 17.9 mg/100 g, respectively. Three different kinds of extract were prepared from 18M-IQFO: a hot-water extract (HE), scrap enzymatic hydrolysate (EH), and complex extract (CE). The respective extracts contained 5.5, 8.6, and 6.6% crude protein and 281.7, 366.0, and 343.0 mg/100 g amino nitrogen, and had 811, 359, and 1,170 mL/kg extraction yields. The CE was superior to the traditional HE in terms of the extraction yield, amino-nitrogen content, and organoleptic qualities, except for the odor. To improve flavor via the Maillard reaction, the reaction system used to produce a desirable flavor comprised CE (Brix $30^{\circ}$), 0.4 M glucose, 0.4 M glycine, and 0.4 M cysteine solution (4:2:1:1, v/v). The reaction time and pH were the independent variables, and the sensory scores for baked potato odor, masking shellfish odor, and boiled meat odor were the dependent variables. The surface response methodology (RSM) analysis of the multiple responses optimization gave a reaction time of 120.6 minutes and pH 7.33 at $120^{\circ}C$. The reaction improved the flavor of CE considerably, as compared to that of the unreacted extract.