• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.904-909
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• 1996

To investigate effects of sugars on the retrogradation of rice flour gels, sucrose and isomaltooligosaccharide (1, 2, and 5%, w/w on the flour basis were added to 50% Dongjinbyeo rice flour gels and stored at different temperature $(20^{\circ}C,\;4^{\circ}C)$ far 1, 3 and 6 days. Changes on the degree of retrogradation (DR) of these rice flour gels were measured by α-amylase-iodine method, DSC and X-ray diffractometry. DRs of rice flour gels increased over storage and showed a rapid increase up to 3 days and then decreased thereafter. DRs of rice flour gels with sucrose or oligosaccharide also increased rapidly until 3 day storage but these values were lower than those of rice flour gels without sugar. DRs of rice flour gels with oligosaccharide were lower than those of gels with sucrose. Changes in enthalpy of rice flour gels measured by DSC showed the same tendency with those in DRs of rice flour gels by ${\alpha}-amylase-iodine$ method, but varied with sugar levels.

• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.125-135
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• 2020

This study analyzed the content of eight biogenic amines (BAs), including histamine, in 198 fishery products (121 school-meal products and 77 distributed products) in Korea in 2019. Changes in BA content according to time, temperature, and salt treatment in Japanese Spanish mackerel, chub mackerel, and salmon were also observed. The average histamine content of 198 fishery products was 0.4±2.3 mg/kg, and all were within histamine criteria (200 mg/kg or less). As a result, the margin of exposure (MOE) was calculated to evaluate the risk of fishery products, and school-meal fishery products were evaluated as safe with a MOE of 1 or more. At 30℃, the histamine content of the fish increased rapidly to 144 mg/kg (Japanese Spanish mackerel, 36 h), and 308 mg/kg (chub mackerel, 24 h). When the Japanese Spanish mackerel, chub mackerel, and salmon were stored at 4℃, histamine was not detected for 3 days, and it was not detected for 14 days at -20℃. The BA content (histamines, etc.) of salt-treated Japanese Spanish mackerel and chub mackerel was lower than that of fish not treated with salt.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1312-1320
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• 1998

Some commercial beef loins in raw state were packaged with PVDC as aerobic and vacuum condition. The other beef samples were cooked until core temperature arrived at $70^{\circ}C$ and then packaged immediately in the same way as the raw state. These samples were irradiated by electron beam (0, 1, 2 kGy), and then stored in refrigerator $(2{\sim}4^{\circ}C)$. Identity and quantity of cholesterol oxides were analysed at the 0, 7th, 14th day of storage. In the samples that were raw and packaged aerobically, $7{\alpha}-hydroxycholesterol,\;{\beta}-epoxide,\;7{\beta}-hydroxycholesterol$ and 7-ketocholesterol were detected over $0.5\;{\mu}g/g$. Cholestanetriol and${\alpha}-epoxide$ were detected at levels below $0.5\;{\mu}g/g$ during storage. In the samples that were raw and vacuum-packaged, $7{\alpha}-hydroxycholesterol$, 7-ketocholesterol and cholestanetriol were detected. In the samples that were cooked and packaged aerobically, cholestanetriol and ${\alpha}-epoxide$ were detected below $0.5\;{\mu}g/g$ during storage. $7{\alpha}-hydroxycholesterol,\;{\beta}-epoxide,\;7{\beta}-hydroxycholesterol$and 7-ketocholesterol were detected as $1.53{\sim}26.81,\;1.07{\sim}5.23,\;40.64{\sim}101.30\;and\;7.16{\sim}33.91\;{\mu}g/g$, respectively. In all results, total amounts of cholesterol oxide increased significantly as irradiation dose and storage time increased (P<0.05).

• The Korean Journal of Nuclear Medicine
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• v.36 no.3
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• pp.195-202
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• 2002

Purpose: For clinical application of beta-emitter labeled antibody, high specific activity is imporiant. Carrier-free $^{188}Re$ from $^{188}W/^{188}Re$ generator is an ideal radionuclide for this purpose. However, low stability of $^{188}Re$ labeled antibody, especially in high specific activity, due to radiolytic decomposition by high energy (2.1 MeV) beta ray was problem. We studied the stability of $^{188}Re$ labeled antibody, and stabilizing effect of several stabilizers. Materials and Methods: Pre-reduced monoclonal antibody (CEA79.4) was labeled with $^{188}Re$ by incubating with generator-eluted $^{188}Re-perrhenate$ in the presence of stannous tartrate for 2 hr at room temperature. Radiochemical purity of each preparation was determined by chromatography. Human serum albumin was added to the labeled antibodies (2%). Stability of $^{188}Re-CEA79.4$ was investigated in the presence of ascorbic acid, ethanol, of Tween 80 as stabilizing agents. Results: Labeling efficiencies were $88{\pm}4%\;(n=12)$. Specific activities of $1.25{\sim}4.77MBq/{\mu}g$ were obtained. If stored after purging with $N_2$, all the preparations were stable for 10 hr. However, stability decreased in the presence of air. Perrhenate and $^{188}Re-tartrate$ was major impurity in declined preparation. colloid-formation was not a significant problem in all cases. Addition of ascorbic acid stabilized the labeled antibodies either under $N_2$ or under air by reducing the formation of perrhenate. Conclusion: High specific activity $^{188}Re$ labeled antibody is unstable, especially, in the presence of oxygen. Addition of ascorbic acid increased the stability.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.129-142
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• 1976

Optimum doses The optimum dose that may be defined as the dose below the maximum permissible dose, yet would bring about a significant storage life extension at refrigerated temperatures, varied with species of fish as well as with the postirradiation storage temperatures. Thus the dose of 0. 1 Mrad was considered to be optimum for the croaker and yellow corvenia at $0^{\circ}C$, while at $5^{\circ}C$ the dose of 0.2 Mrad would be suitable for both species. The roundnose flounder was more radiosensitive and even at the dose of 0.1 Mrad a slight irradiation odor was detected immediately after the radiation treatment. Such degree of irradiation odor disappeared upon storage, therefore, the dose of 0.1 Mrad was considered to be optimum for the roundnose flounder at both $0^{\circ}\;and\;5^{\circ}C$. Storage life extension The croaker meats irradiated at 0.1 Mrad could be held at $0^{\circ}C$ as long as 5 weeks in good acceptable conditions, while the unirradiated control became unacceptable within 2 weeks-3-4 for extension of storage life at $0^{\circ}C$. At the storage temperature of $5^{\circ}C$, the storage life of 0.2 Mrad irradiated samples was extended from less than one week to 4 weeks--4-5 fold extension. The storage life extension of 0.1 Mrad irradiated yellow corvenia at $0^{\circ}C$ was from less than 2 weeks for the unirradiated to 4 weeks-approximately a-s folds and that of 0.2 Mrad irradiated samples stored at $5^{\circ}C$ was from 5 days to 3 weeks 4-5 folds. The roundnose flounder meats irradiated at 0.1 Mrad could held at $0^{\circ}C$ for 3-4 weeks as compared to less than 1 week for the unirradiated and at $5^{\circ}C$ the storage life could be extended from less than 3 days to up to 3 weeks. Thus the storage life extension by 4-5 folds and by 6-7 folds was possible at $0^{\circ}C\;and\;5^{\circ}C$ storage, respectively. Postirradiation storage microbiology and biochemistry In general 10 fold reduction of initial microflora was realized as a result of irradiating fish samples at 0.1 Mrad. The extent of microflora reduction increased with increasing doses applied, but not proportionately dependent. The microbial growth in the irradiated was severely retarded during the subsequent storage period, lagging far behind that of the irradiated control samples except in the late storage phase, when the levels of microflora of the irradiated either approached to or rose above the levels of the unirradiated. The microbiological changes caused by irradiation was reflected in the pronounced suppression of TVB and TMA accumulation during the storage period. This suggests that irradiation treatment brought about both quantitative and qualitative changes in microflora initially present and it is reasonable to suggest that the microflora removed by irradiation in fact represent most of the flora capable of producing TVB and TMA in normal fish spoilage process.

• Journal of Nutrition and Health
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• v.9 no.1
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• pp.104-109
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• 1976

Condiments such as welsh onion, garlic, ginger, black pepper, red pepper, japanese pepper, mustard, horse radish, monosodium glutamate and sugar were ground by a homogenizer, and 0%, 1%, 5%, and 10% of each of the ground condiments were put into 0.2% ${\alpha}-amylase$ solution for storage at the temperature of $15^{\circ}C$. ${\alpha}-amylase$ activity then was measured by the Wohlgemuth method at 48-hour interval, and the following results were obtained. 1) Among the condiments, black pepper and sugar checked the ${\alpha}-amylase$ activity most, about 80% in comparison with control. 2) Welsh onion, garlic, mustard, and ginger checked the ${\alpha}-amylase$ activity, about 50% in comparison with control, irrespective of the time stored. 3) The low concentration of red pepper, horse radish, japanese pepper and mono-sodium glutamate checked the ${\alpha}-amylase$ activity about 50%, while the high one did below 75% in comparison with control. To conclude: all the condiments used in the experiment checked ${\alpha}-amylase$ activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.171-176
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• 2006

The effect of storage temperature on the quality and antioxidative activity Whangseoke sauce was studied over a period of 240 days. Fermented Whangseoke with $25\%$ salt were stored at $25^{\circ}C$. The quality change and antioxidant activity of Whangseoke in linoleic acid emulsion was evaluated with various parameters including acids values, peroxide values, TBA values, reducing sugar, brown color intensity, electron donating ability and reducing power at various time intervals for 240 days of storage. In general, it was observed, in all sample, that peroxide values, brown color intensity, electron donating ability and reducing power gradually increased, while reducing sugar decreased during storage at $25^{\circ}C$. The antioxidative activities of fermented Whangseoke were determined on tile linoleic acid emulsion system. The results showed that Whangseoke had antioxidant activity. These results suggest that antioxidant activity of Whangseoke seemed to influence by Maillard reaction products during the storage periods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.791-798
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• 1998

To develop natural flavoring substances. optimal hydrolysis conditions for two stage enzyme hydrolysates (TSEH) using low-utilized shellfishes such as purplish clam and frozen oyster stored at $-20^{\circ}C$ for 60 days. The optimal conditions for TSEH method were revealed in temperature at $50^{\circ}C$ 3 hours digestion with alcalase (Aroase AP-10, $0.3%$ w/v, pH 8.0) at the 1st stage and $45^{\circ}C$ 2 hours digestion with neutrase (Pandidase NP-2, $0.3\%$ w/v, pH 6.0) at the 2nd stage. Among water extracts, autolytic extracts and 4 kinds of enzyme hydrolysates tests, TSEH method was superior to other methods on the aspect of yields, nitrogen contents, taste such as umami and control of off-flayer formation, and transparency of extracts. From the results of chemical experiments and sensory evaluation, we may conclude that TSEH from low-utilized marine products is more flavorable compared the conventional enzyme hydrolysates, it could be commercialized as the seasoning substances.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.309-316
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• 1988

Several experiments were conducted to investigate the achene viability and growth characteristics of Eclipta prostrata (L.) L. No dormancy and no after-ripening requirement were found for E. prostrata achenes. When achenes were stored at room temperature, germination did not decrease with up to 5 months storage. Large differences in loss of viability of E. prostrata achenes occurred when different dehydration methods were used. Immediate dehydration resulted in high viability, but slow dehydration resulted in severe loss of viability. Achene viability at shallow burial depths (5 and 10 cm deep) was lower under upland soil conditions than under lowland soil conditions. Seedling growth was greatly reduced when flooding to a depth of 10 cm occurred at or before the 4-leaf stage. Flooding after the 4-leaf stage stimulated stem elongation. Branching started from the second week and usually terminated at the tenth week. Leaf size was determined by the branch which are related to the assimilate supply. Flowering of E. prostrata started during the fifth week after emergence, and mature achenes were produced from the sixth week. Ten to 14 days were needed for the achenes to mature. About 14,000 achenes were produced on each plant. Achene production per week increased from the sixth week to the tenth week and thereafter it declined. The average number of achenes per inflorescence decreased with delay in flowering.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.6-13
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• 1986

Experiments were conducted to study the effects of formic acid on the quality of the rye silages at the different dry matter content (19.2, 28.6 and 32.2%) and different formic acid addition levels (0.00, 0.24, 0.48 and 0.71%). Rye were taken at vegetative stage (plant height 40cm) on November 29, 1984. Herbage were adjusted dry matter contents by wilting. Materials were ensiled in small polyethelene film bag after addition planned formic acid, and stored under room temperature. The results obtained are as follows: 1. In the visual observation of silage quality by addition of formic acid in unwilted silage show more clear brownish-yellow color and sweet flavor and less acidity compared with untreated formic acid. 2. The pH values of the silage increased by increasing DM content. At lower dry matter contents in materials the pH values decreased with increased formic acid levels. At higher dry matter content silage, however, non significant difference were observed. 3. The formation of total organic acid decreased by increasing DM content in the materials, and there appeared a significant difference (P<01) among formic acid levels. The organic acid contents in silage decreased with higher formic acid levels. 4. The water soluble carbohydrate in silage increased by increasing DM content. And it was also increased (P<01) with increased formic acid addition level. 5. The production of NH_3 - N decreased (P<01) with increasing the addition of formic acid, and decreased by increasing DM content in materials. 6. The in vitro dry matter digestibility of silages showed not difference among dry matter contents of the materials but at 0.71% addition of formic acid in unwilted silages appeared higher (P<05) digestibility compared the others (0.00% and 0.24%).