• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.859-867
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• 1997

In order to utilize the processing wastes of squid, chitosans were manufactured from the pens of domestic squid, Todarbdes pacificus and foreign squid, Ommastrephes bartrami and then, its rheological properties were studied. The amounts of nitrogen and minerals of the domestic squid pens were $11.4\%\;and\;0.1\%$ respectively, whereas those of its chitosan were $7.5\%\;and\;0.2\%$. In case of foreign squid pen and chitosan, the amounts of nitrogen and minerals were $12.1\%,\;0.8\%\;and\;7.8\%,\;0.2\%$ respectively. Intrinsic viscosity $([\eta]) $ of domestic and foreign squid pen chitosans were decreased with increasing pH from 3.4 to 5.4 which might be due to the reduced repulsion in inter- of intra- chitosan molecules. Intrinsic viscosity of the domestic and foreign squid pen chitosans were decreased with increasing NaCl concentration thus indicated that the domestic and foreign squid pen chitosans were polyelectrolyte molecules and stiffness of squid pen thitosans were 0.11 similar to that of k-carrageenan. Flow type of squid pen chitosan solutions were pseudoplastic fluids without yield stress by the viscosity measurement. But the squid pen chitosan solutions showed newtonian fluid up to $0.15\~0.24\%$ concentration for domestic and $0.21\~0.24\%$ concentration for foreign at $10\~50\%$. Concentration dependence of consistency index in infinitive dilute domain (Kc) were higher in the dilute domain than entangled domain. Activation energies (Ea) of the squid pen chitosans were 3.7, 6.3, 3.6, 4.0 and 4.1 Kcal/g moi for domestic and 3.2, 3.1, 3.4, 3.8 and 3.6 Kcal/g mol for foreign at 0.1, 0.15, 0.25, 0.35 and $0.5\%$, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.303-311
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• 1986

This work was designed as basic studies on the development of diet for the treatment of obesity. The effect of alginic acid which is the major component of brown algae was investigated by comparing with agar, cellulose, carboxymethylcellulose (CMC), chitin, and lignin as dietary fibers. These dietary fibers ($10\%$) supplemented to basic diet were fed ad libitum to Sprague Dawley rat for 4 weeks, and the inhibitory effects on obesity were evaluated by measuring body weight gain and feed efficiency, the content of glucose and cholesterol in serum, lipase activity in serum, lipid content in liver, adipose tissue around epididymis and ovarium, and Lee index etc. Among the inhibitory effect of these dietary fibers on obesity, lignin was the most effective (p<0.001), followed by Na-alginate (p<0.01) for body weight gain, but lignin was the most effective, followed by CMC, and followed by Na-alginate for feed efficiency (p<0.001). In the inhibitory effects on lipid accumulation in liver and adipose tissue around epididymis and ovarium, lignin and Na-alginate group among these dietary fibers were more effective than others, but there was no significant difference between male and female. The inhibitory effect on obesity evaluated by Lee index was effective in the order of Na-alginate>lignin>CMC>chitin>cellulose (p<0.001). The decreasing effects of lipid content in liver by dietary fibers were found in the order of agar>CMC>cellulose>Na-alginate>chitin>lignin (p<0.001). Glucose content in serum was significantly decreased in cases of CMC, lignin and Na-alginate, whereas a slight difference was found in chitin, but cholesterol content in serum was decreased for all dietary fibers examined except cellulose group. The increasing effect of lipase activity in plasma was found in cases of Na-alginate and chitin, while cellulose, CMC and lignin groups were decreased.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.219-226
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• 1986

To confirm the application of a newer in vitro assays to determining the nutritional value of marine crustaceans (mainly shrimps and crabs), which have been considered to be highly nutritive depending on their levels of the essential amino acids and digestibility, their C-PERs and DC-PERs were determined and studied the factors influencing their in vitro results. Four species of seawater shrimps and 2 species of seawater crabs were used in this experiment. The in vitro digestibilities showed $83{\sim}86\%$ for raw shrimps and the trypsin indigestibile substrate content (TIS) was ranged from 1.32 to 3.33 mg/g solid expressed quantitatively as mg of purified soybean trypsin inhibitor. The smaller size of shrimps revealed a greater in vitro digestibility and a lower contents of TIS. It was noted that the in vitro digestibility of raw blue crab meat was around $85\%$ while boiled tenner crab meat showed $86\%$ or above, and the leg meat had the greatest in vitro digestibility in the various parts of crab meats. The poor in vitro digestibilities for shrimp's and crab's meat, compared with that of the other seafoods as noted in previous reports, suggest that the drop in pH, due to the change in their freshness during harvesting and frozen storage, resulted in underestimating their digestibilities using four-enzyme digestion technique. The lysine contents in all samples were higher than that of ANRC casein but they contained a slightly lower sulfur-containing amino acids than those in ANRC casein. But the other EAA, such as valine, tyrosine and phenylalanine, were found to be a half as little as that in casein and played a key-factor in calculation of C-PER or DC-PER. It was observed that the value of C-PER and DC-PER for all samples ranged from 2.1 to 2.4, and the predicted digestibilities showed $90\%$ or above in all samples. It was a different results from the fact that the animal proteins bear a higher values and predicted digestibilities than those of C-PER values. The lack of correlation between C-PER and DC-PER values is attributable to the fact that the lower content of valine, tyrosine and phenylalanine, and drop in pH owing to the changes of freshness in marine crustacea proteins. Therefore, if a newer in vitro digestion technique-which are taken into account the pH drop before digestion, TIS content and released free amino acids and/or peptides-developed, C-PER assays can provide more advantages in assessing the protein nutritional value of marine crustacea than any other in vitro assays.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.327-332
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• 1986

The present study was carried out to investigate the antioxidative effect of ginger extracts on fish oil. The changes of sardine oil with and without ginger extract were estimated by periodically measuring peroxide value (POV), thiobarbituric acid (TBA) value, weighing method, acid value (AV) and fatty acid composition. The results obtained are summarized as follow : The POV of sardine oil by $80\%$ ethanol extract and fat soluble fraction obtained from ginger during storage was rapidly increased after 10 days, while water soluble fraction was slowly increased during storage for 25 days. TBA value of sardine oil by water soluble fraction was appeared to increase slowly until 10 days, but that of $80\%$ ethanol extract and fat soluble fraction was remarkably increased in early stages of storage. The weighing change of sardine oil by $80\%$ ethanol extract and fat soluble fraction were shown $3.5\%\;and\;1.7\%$ for 15 days, but by water soluble fraction was marked $0.5\%$ of weight gain. Docosahexaenoic acid (DHA) in polyunsaturated fatty acid of sardine oil during storage markedly decreased, but by the addition of each fraction of ginger extracts, the oxidative degradation of DHA was effectively inhibited, of which water soluble fraction was most effective.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.227-233
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• 1986

The compositions and seasonal variations of free sugars and non-volatile organic acids of brown algae, such as Ecklonia cava, Sargassum ringgoldianum and Myagropsis myagroides were investigated by gas chromatography. Four kinds of free sugars, such as xylose, glucose, galactose and floridoside were identified. The most abundant one was floridoside marking 118.7 mg/100 g, 90.9 mg/100 g and 70.0 mg/100 g in Ecklonia cava, Sargassum ringgoldianum and Myagropsis myagroides, respectively. There were not distinguishable seasonal variations in the contents of free sugars in all the samples. In the case of organic acids, nine kinds were identified in Ecklenia cava and major ones were succinic, citric, malic, fumaric, oxalic and lactic acid, of which succinic acid was the most abundant one marking $30.6\%$ of total organic acids. In Sargassum ringgoldianum and Myagropsis myagroides, eight kinds were identified, which major ones were succinic, citric and malic acid in both samples, and they marked $68.4\%$ and $61.1\%$ of total organic acids in Sargassum ringgoldianum and Myagropsis myagroides, respectively. There were not distinct changes in the content of total organic acids according to seasons in all the samples examined. The contents of total organic acics in Ecklonia cava was a little more than Sargassnm ringgoldianum and Myagropsis myagroides.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.187-194
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• 1986

For the purpose of obtaining basic data which can be applied to evaluate the quality of the retortable pouch and tin-plated canned product, the canned sardine and the retort pouched sardine were prepared and compared in terms of thermal sterilization times required and product duality during storage. Retort pouched sardine required $20\%$ less thermal sterilization time than the canned sardine. Volatile basic nitrogen (VBN) and amino nitrogen ($NH_2-N$) contents in both canned and retort pouched sardine showed little difference during processing and storage. During storage, peroxide value (POV) and thiobarbituric acid (TBA) value of the canned sardine had a slightly higher value compared to the retort pouched sardine, but acid value (AV) revealed little difference between both canned and retort pouched sardine. Trimethylamine (TMA) content of the both canned and retort pouched sardine showed little difference during processing and storage. The inosinic acid (IMP) content in canned and retort pouched sardine was $8.39{\sim}9.80{\mu}mole/g$ range, and had no significant change during processing and storage. The retort ponched sardine revealed a smaller reduction in polyenoic acid than the canned sardine during processing and storage. Among the TPA (texture profile analysis) parameters, hardness maintained a slightly higher value in the retort pouched sardine than in the canned sardine. Color values showed that the retort pouched sardine was generally lighter than the canned sardine. In sensory evaluation, the retort pouched sardine was scored slightly higher, in most cases, for color, flavor, texture, taste and overall acceptance than the canned sardine. It was concluded from the results that the retort pouched sardine was at least equal to the canned sardine in product quality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.511-518
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• 1985

As one of the sensory factors for characterizing food quality, volatile compounds have been particularly contributed to sensory evaluation of fermented sea foods in Korea. But no chemical investigation of the volatile compounds of fermented anchovy as one of the most favored fermented sea food products has been reported. Accordinglry, for a series study of processing of low salt fermented sea foods, changes in volatile compounds and fatty acid composition of fermented anchovy with low salt contents ($4\%$ of salt contents) were experimented fermentation comparing with conventional fermented anchovy ($20\%$ of salt contents). Total lipid of raw anchovy was composed of $77.6\%$ of neutral lipid, $22.1\%$ of phospholipid and $0.3\%$ of glycolipid. And polyenoic acid was held $39.8\%$ of fatty acid composition of total lipid and the major fatty acids in those were $C_{22:6},\;C_{20:5}$. During the fermentation of anchovy saturated fatty acid ($C_{16:0},\;C_{18:0},\;C_{l4:0}$) and monoenoic acid ($C_{16:1},\;C_{18:1}$) increased while polyenoic acid ($C_{22:6},\;C_{20:5}$) decreased greatly. Thirty-eight kinds of volatile component from the whole volatile compounds obtained from fermented anchovy after 90 days fermentation were identified, and composed of some alcohols (8 kinds), carbonyl compounds (9 kinds), hydrocarbons (8 kinds) and fatty acids (8 kinds). During fermentation 8 kinds of volatile acids, 5 kinds of amines, 9 kinds of carbonyl compounds were also detected. Those volatile acids such as acetic acid, isovaleric acid, propionic acid, n-butyric acid were the major portion of total volatile fatty acids of 60 days fermented anchovy prepared with low salt contents. On the other hand, carbonyl compounds such as ethanal, 3-methyl butanal, hexanal, 2-methyl propanal were the major ones, while TMA held the most part of volatile amines in fermented anchovy with low salt contents after 60 days. Conclusively, there was little difference in composition of volatile components, but merely a little difference in content of those between low salt fermented anchovy and conventional fermented ones.

• Analytical Science and Technology
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• v.15 no.5
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• pp.417-426
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• 2002

Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry (ICP-DRC-QMS) was characterized for the detection of the six naturally occurring calcium isotopes. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio. This experiment shows that the potentially interfering ions such as $Ar^+$, ${CO_2}^+$, ${NO_2}^+$, $CNO^+$ at the calcium masses m/z 40, 42, 43, 44 and 48 were removed by flowing $NH_3$ gas at the rate of 0.7 mL/min $NH_3$ as reactive cell gas in the DRC with a RPq value (rejection parameter) of 0.6. The limits of detection for $^{40}Ca$, $^{42}Ca$, $^{43}Ca$, $^{44}Ca$, and $^{48}Ca$ were 1, 29, 169, 34, and 15 pg/mL, respectively. This method was applied to the determination of calcium in synthetic food digest samples (CCQM-P13) provided by LGC for international comparison. The isotope dilution method was used for the determination of calcium in the samples. The uncertainty evaluation was performed according to the ISO/GUM and EURACHEM guidelines. The determined mean concentration and its expanded uncertainty of calcium was ($66.4{\pm}1.2$) mg/kg. In order to assess our method, two reference samples, Riverine Water reference sample (NRCC SLRS-3) and Trace Elements in Water reference sample (NIST SRM 1643d), were analyzed.

• Analytical Science and Technology
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• v.25 no.3
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• pp.171-177
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• 2012

A determination method of aromatic amino acids such as trytophan (Trp), tyrosine (Tyr), and phenylalanine (Phe) using luminol-$H_2O_2$-Cu(II) system has been presented. In the presence of an aromatic amino acid, the enhanced chemiluminescence (CL) intensity of luminol-$H_2O_2$-Cu(II) system was obtained by forming a complex between Cu(II) and the amino acid. Based on the above phenomenon, a sensitive and fast determination of three aromatic amino acids was performed using the CL method in batch-type detection system. To optimize determination conditions, the kinetic influence of an aromatic amino acid on the luminol-$H_2O_2$-Cu(II) system and the effects of $H_2O_2$ and Cu(II) concentration, pH, and buffers were investigated. Under the optimized conditions, the calibration curve was linear over the range from $1.0{\times}10^{-6}$ to $2.0{\times}10^{-5}\;M$ for Trp, $1.0{\times}10^{-6}$ to $2.0{\times}10^{-5}\;M$ for Try, and $2.0{\times}10^{-6}$ to $2.0{\times}10^{-5}\;M$ for Phe, respectively. In this range, reproducibility (RSD, n = 4) of Trp, Try, and Phe were 3.21%, 2.64%, and 2.48%, respectively. The limit of detection ($3{\sigma}/s$) was calculated to be $6.8{\times}10^{-7}\;M$ for Trp, $5.7{\times}10^{-7}\;M$ for Try, and $9.6{\times}10^{-7}\;M$ for Phe.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.443-452
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• 2006

The four rice(Oryza sativa L.) lines, previously demonstrated to have vigorous herbage production at the vegetative growth stage, were investigated for their growth traits, dry matter yield and feed value using the twice-cutting system that 1st-cut is harvested at panicle formation stage and 2nd-cut at the yellow ripen stage. The twice-cutting system is regarded as an effective method in the production of forage rice by escaping lodging and insect damages caused by the overgrowth and typhoon around the heading stage.The feed value of the twice-cut rice plant of there lines were compared with the control of normal, cutting at the yellow ripen stage. The relative feed value(RFV), the total digestible nutrient(TDN) and the crude protein(CP) content of the twice-cut straw were higher the control in every lines. However, the dry matter yield (DMY), represented by the summed forage production of 1st and 2nd cut-rice plant, were lower the control, and the DMY of straws were increase but grains were decrease for twice-cutting system. In addition, TDN yield showed the similar tendency with DMY.Recently, as one of the breeding aims the researches for improving the digestibility of rice straw have been required. In this regard, twice-cutting system is recognized with the fact that it has the effect which raises the digestibility of the straw. Especially, the 2nd cut of IR73111-B-R-15-3-1 line was similar to the control at the TDN yield of straw, and would be used as a breeding material for product the roughage of good quality.