• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.5
• /
• pp.768-773
• /
• 1996

The changes in amino acid contents of sea mussel and baby clam during drying at 40, 50 and 6$0^{\circ}C$ and storage at low temperature(4$^{\circ}C$) and room temperature(2$0^{\circ}C$) were investigated. Amino acids of 17kinds were analyzed in sea mussel and baby clam. Total amino acids content of raw sample were similar to sea mussel and baby clam(6575.30mg%, 6764mg%), decreased during drying and rate of decreasing was higher in baby clam than that of sea mussel. The content of Glx was highest in sea mussel(790.55mg%) and baby clam(990.89mg%), other amino acids differed from samples. The content of amino acids of low drying temperature(40 and 5$0^{\circ}C$) decreased was higher than that of high drying temperature(6$0^{\circ}C$). The rate of decreasing was higher at room temperature(2$0^{\circ}C$) storage and short storage periods than that of low temperature(4$^{\circ}C$) storage and long storage periods.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.18 no.5
• /
• pp.417-423
• /
• 1985

In succession to the previous paper, the present study was directed to investigate the nonvolatile organic acids composition in raw and belied-dried products of oyster, sea-mussel, baby clam and hen clam by gas liquid chromatography. The results obtained are summarized as follows : In four kinds of the samples examined, eight kinds of organic acids were identified and determined in oyster, sea-mussel and baby clam, and nine kinds in hen clam. The major organic acids in oyster were pyroglutamic, succinic and malic acid which was $94.2\%$ of total quantity of organic acid, and those in sea-mussel, baby clam and hen clam were succinic and malic acid which were $90.8\%,\;89.7\%\;and\;86.4\%$ of total acids, respectively. The most abundant organic acid in sea-mussel, baby clam and hen clam was succinic acid that was $80.6\%,\;84.9\%\;and\;73.2\%$ in total acids, repectively. And that of oyster was pyroglutamic acid which marked $38.8\%$ in total acids, and the next one was succinc acid marked $34.4\%$. In the total quantity of organic acid, the highest was 913.0 mg/100g in oyster which showed 4.5 times as much as in hen clam, followed by 478.4 mg/100g in sea-mussel, 246.3mg/100g in baby clam, and the least was 201.2 mg/100g in hen clam. The decreasing rate of total quently of organic acids by boiled-dried procersing was the highest in oyster, $54.7\%$, followed by $46.5\%$ in sea-mussel, $37.1\%$ in hen clam and $29.4\%$ in baby clam. The decreasing rate of each organic acid shelved much difference according to the samples examined, in general, great in malic, fumaric and proglutamic acid ana less in succinic, lactic and oxalic acid.

• Korean Journal of Food Science and Technology
• /
• v.28 no.5
• /
• pp.882-887
• /
• 1996

Some taste compounds such as nucleotide and their related compounds, trimethylamine oxide (TMAO), trimethylamine (TMA) and total creatinine of sea mussel and baby clam during drying at 40, 50 and 60^{\circ}C$ and storage at low temperature$(4^{\circ}C)$ and room temperature$(20^{\circ}C)$ were investigated. Six kinds of nucleotide and their related compounds such as adenine triphosphate (ATP), adenine diphosphate (ADP), adenine monophosphate (AMP), inosine, adenosine and hypoxanthine were analyzed. The contents od adenosine in raw sample was high in sea mussel and baby clam. The contents of ATP, ADP and AMP decreased, while those of inosine and hypoxanthine increased during drying and storage periods. The contents of TMAO, TMA and total creatinine were low in sea mussel and baby clam. TMAO and total creatinine decreased but TMA increased during drying and storage periods. The rate of change was high in room temperature storage and for long storage periods than that of low temperature storage and for short storage periods.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.5
• /
• pp.774-778
• /
• 1996

The changes in organic acid contents of sea mussel and baby clam during drying at 40, 50 and $60^{\circ}C$ and storage at low $temperature(4^{\circ}C)$ and room $temperature(20^{\circ}C)$ were investigated. Organic acids of 8 varieties were determined and the content of succinic acid occupied over 90% of total organic acids in sea mussel(410.9mg%) and baby clam(96.5mg%). Malic acid was in order in sea mussel(41.2mg%) and lactic acid was in order in baby clam(61.9mg%). The content of organic acids was decreased during drying and rate of decreasing was higher at low drying temperature(40 and $50^{\circ}C)$ than that of high drying $temperature(60^{\circ}C).$ The decreasing rate was higher at room $temperature(20^{\circ}C)$ storage and long storage periods than that of low $temperature(4^{\circ}C)$ storage and short storage periods.

• Korean Journal of Food Science and Technology
• /
• v.21 no.5
• /
• pp.606-612
• /
• 1989

A New lectin from baby clam, Tapes japonica, was isolated and purified through the following procedures; acetone powder, 0.15M NaCl extraction, ammonium sulfate fractionation, N-acetyl-D-galactosamine-agarose affinity column, and ion exchange Mono Q of FPLC. This lectin nonspecifically agglutinated human erythrocytes but didn't agglutinate mouse and rabbit erythrocytes. And the lectin neither stimulated human lymphocytes nor agglutinated Sarcoma 180 cells. On polyacrylamide gel electrophoresis, the lectin migrated as a major single band indicating homogeneous. A molecular weight was estimated to be about 131,000 daltons by Biogel P-300 and 125,000 daltons by SDS-PAGE without ${\beta}-mercaptoethanol$. This lectin is supposed to be a tetramer composed of heterogeneous subunits, about 30,000 and 33,000 daltons. Baby clam lectin was inhibited by EDTA and recovered agglutinating activity by $Ca^{++}\;and\;Mn^{++}$. This lectin is revealed as glycoprotein that contained about 4.2% neutral sugar.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.2
• /
• pp.143-148
• /
• 1998

This study was carried out in order to investigate oxidative deterioration during dehydration at $40^{\circ}C,\;50^{\circ}C$ and $60^{\circ}C$ of sea mussel and baby clam. Moisture content was decreased with drying temperature and time. Sea mussel was dehydrated more rapidly than baby clam that had Harder muscle tissue. Both samples were not reached to Aw 0.62 in case of 10 hrs drying at $40^{\circ}C$, But it reached within 8 hrs in sea mussel and 10 hrs in baby clam at $50^{\circ}C$, respectively. Even if $60^{\circ}C$ could speed up drying, it caused to form more free fatty acid, peroxide, thiobarbituric acid and brown pigments. Lipophilic brown pigment was 10 times higher than hydrophilic and actively increased in all samples. fluorescence intensity was also increased with drying temperature and time. Particularly, it was higher sea mussel than baby clam more or less.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.17 no.4
• /
• pp.327-332
• /
• 1984

This experiment was carried out to investigate the changes of cholesterol contents during the processing of various marine products. For the above purpose, squid, eel, mackerel, baby clam and sea mustard were sun-dried, roasted, salted-dried, boiled-dried and salted, respectively. In raw samples, the highest content of cholesterol was 761 mg/100g in squid, following by eel, baby clam, mackerel and sea mustard in order, and there was no significant relationship between cholesterol and lipid contents. The cholesterol contents of the used samples were decreased during the processing except baby clam. The decreasing ratios of the cholesterol contents during the processing were $66.4\%$ in squid, $43.6\%$ in eel, $41\%$ in mackerel and $58\%$ in sea mustard. While the cholesterol content of baby clam was increased by 1.6 times compared with that of raw sample. Considered from the results, it seems that the changes of cholesterol content during processing depended upon the changes of lipid content in the sample.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.8 no.1
• /
• pp.20-30
• /
• 1975

It is matter of fact processing technology must affects the quality and yield of final product and these also depend on the selection of raw material directly or indirectly. So that the estimation of tile preprocessing condition of shellfish is of great importance for distributors and processors. This study was attempted to establish the basic data for evaluating the processing suitability of baby clam, which is one of the five important shellfishes for domestic use and export. The important results are as follows: 1. The ratio of meat volume and meat weight to the holding capacity by shells may be useful for measuring the condition index of baby clams. 2. Baby clams grown in the beds with the composition of a large quantity of gravel were low in condition index value than in sand and mud. 3. If the green feed phenomenon was the prime consideration for canned baby clams, tile most suitable harvest season if October. In this period, the digestive tract in body was almost colorless. 4. As a whole, seasonal changes of moisture and fat content in baby clams were reversely correlated. Protein content increased from April and slightly decreased for a while from July to August and increased again from September. In March, the content of glycogen was 6.3 to 6.8 percent. From this period to October, glycogen was rapidly decreased. In October, it was only 0.1 to 0.2 percent but increased from November. There were little seasonal changes in pH value and crude ash content. The pH value of meat was 6.0 to 6.2 and crude ash content was about 2 percent. 5. By the results of condition index and chemical composition of baby clams, the suitable harvest season as raw materials for processing was from March to June and from September to October. 6. The steamed baby clam meat was packed with 2 percent salt solution containing 0.15 percent, citric acid or 0.5 percent $Na_2$ EDTA in a round sanitary tin can coated with C-enamel that is 203.9 ml by volume and sterilized for 60 minutes at $112^{\circ}C$. The canned product has shown a good result to reserve the natural characteristics of baby clam through six month storage at room temperature.

• Membrane Journal
• /
• v.10 no.2
• /
• pp.92-101
• /
• 2000

For selective elimination of salt in the boiled extract of baby neck clam (Tapes variegata, BEBNC), electrodialyzer was used and the desalination conditions of BEBNC were determined at various concentrations, pH's and volumes of BEBNC. The ion-exchange membrane with a molecular weight cut off 100 Da was used for desalting of BEBNC. The desalination times on BEBNC concentrations of 0.5％ and 4％ were 100 min and 170 min and the final desalting ratio was above 90％. 1'he desalination of BEBNC at pH 4.0 was 12％ higher than that at pH 9.0 for 60 min. The electrodialysis process could remove above 90％ of the initial salt content in 2％ BEBNC of 1 L for 80 min. The results obtained prove that electrodialysis is a practical solution to the problem of selective elimination of salt from BEBNC.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.13 no.4
• /
• pp.444-450
• /
• 1984

Effects of muscle extracts of five species of fish and shell-fish, mackerel, jack mackerel, yellow corvenia, shrimp and baby-neck clam, on lipid oxidation were investigated using a model system consisting of methyl linoleate absorbed in micro crystalline cellulose and extracts of fishes. Ethanol extracts of both mackerel and jack mackerel apparently showed inhibitory effect on the oxidation of methyl linoleate, while the extract of yellow corvenia, and baby-neck clam showed a slight catalyzed effect on contrary. The ethanol extract of shrimp, however, revealed no effect on the oxidation of methyl linoleate. When the ethanol extracts were dialyzed, the outer fractions of dark fleshed fish had a strong inhibitory effect on the oxidation of methyl linoleate, while the inner fractions did not. The outer fraction of yellow corvenia showed catalyzed effect, but the inner fraction inhibited the oxidation slightly. The outer fraction of shrimp had a strong inhibitory action, but the inner fraction showed no effect. The methanol-water fraction of chloroform-methanol extract of shrimp showed a quite strong inhibitory effect on the oxidation, whereas that of four other samples did the same levels of effect as ethanol extracts.