• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.468-474
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• 1993

A dehydrating sheet comprises polymeric water absorber. which are packed in a semipermeable cellophane film bag allowing selective permeation of water. This sheet dehydration is quite different from conventional drying method such as sun drying, hot-air blast drying and cold air blast drying in a sense that samples are dried without heat treatment. As a part of the studies to develope a new processing method for effective utilization of dark muscle fishes, the preparation of a good quality salted and semi-dried mackerel by the dehydrating sheet was attempted. The dehydration time for preparation of a salted and semi-dried mackerels containing approximately equal moisture content were revealed $180{\sim}510min$ in conventional drying method and $90{\sim}160min$ in this sheet dehydration, respectively. The moisture and histamine contents of those salted and semi-dried mackerels were $59.4{\sim}62.4%$ and $2.5{\sim}3.6 mg/100g$, respectively. The changes in peroxide value, fatty acid composition, brown pigment formation, myofibrillar protein solubility and Ca-ATPase activity during processing of the salted and semi-dried mackerel prepared by the sheet dehydration were more lower than those of products prepared by conventional drying methods. Therefore, these result showed that the quality of a salted and semi-dried mackerel prepared by the sheet dehydration was imperial to that of those products by conventional drying method.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.351-359
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• 1989

This study was conducted to observe the physico-chemical exchange and effect of amino-carbonyl reaction between fructose and glycine . When various buffer solutions were added to equimolar mixture of fructose and glycine at pH 6.0 and $100^{\circ}C$, the browning effect was markedly observed by Mcllvaine buffer. Among the combinations of temperature and reaction time, the deep browning effect was obtained above $100^{\circ}C$, 3hr A marked browning effect obtained above pH 7.0 but little observed below pH 7.0. The browning effect was markedly increased at high fructose concentration. It required 4.0hrs and 32.9hrs to decrease 50% of initial concentration of fructose and glycine at $100^{\circ}C$ and pH 7 but 0.9hrs and 3.8hrs at $120^{\circ}C$, pH 7.0, respectively. The rate constant of fructose and glycine at $100^{\circ}C\;and\;120^{\circ}C$ were $1.78{\times}10^{-1},\;2.11{\times}10^{-2}\;and\;7.74{\times}10^{-1},\;1.83{\times}10^{-1}$, respectively. The formation of HMF was likely to follow the first order kinetics. The addition of 0.1M sodium sulfite, 0.1M sodium bisulfite and 0.1M calcium chloride to equimolar mixture (0.05M) surpressed the reaction up to 76.8%, 76.8% and 96.4%, respectively.

• Korean journal of food and cookery science
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• v.15 no.6
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• pp.555-564
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• 1999

The objective of this study was to investigate the preference of root vegetables and the inhibitory effect of the vegetables on harmful enzymes of intestinal bacteria. Two hundred fifty respondents in Seoul area surveyed to obtain information from Sep. 30 to Oct. 30, 1998. Respondents preferred Inpuomoea batatas (sweet potato, 4.05), Solanum tuberosum(potato, 3.97), Allium cepa(onion, 3.68), Codonopsis lanceolata(3.64) and Raponus sativus(redish, 3.60). The growth of B. breve K-110 was effectively increased by adding 0.5% extract of Solanum tuberosum(139%), Codonopsis lamceolate(145%), Dioscorea japonica(164%), Colocisia antiquorum(144%) extract to the medium. B. breve K-100 for beneficial bacteria, and E. coli HGU-3 or Bacteroides JY-6 for harmful bacteria were used to determine the inhibitory effect of root vegetables on harmful intestinal enzymes after co-culturing harmful and beneficial bacteria. The extract of Solanum tuberosum, Codonopsis lanceolata, Dioscorea japonica (yam) and Colocisia antiquorum (taroes) showed inhibitory effect on ${\beta}$-glucuronidase and tryptophanase of intestinal bacteria. The macromolecules were isolated from Solanum tuberosum, Codonopsis lanceolata, Dioscorea japonica and Colocisia antiquorum by Sephadex G-100 column chromatography. By adding these isolated marcromolecules to the medium, the growth of B. breve K-100 were also increased and high inhibitory effects on the ${\beta}$-glucuronidase and tryptophanase were measured. These results suggested that the harmful enzymes of intestinal bacteria were inhibited by consuming Solanum tuberosum, Codonopsis lanceolata, Dioscorea japonica and Colocisia antiquorum. Therefore, they could prevent gastrointestinal diseases.

• Korean journal of food and cookery science
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• v.31 no.3
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• pp.304-317
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• 2015

For the production of pumpkin paste with respect to heating conditions, we steamed the pumpkin for roughly 15 min, heated it with high pressure treatment for 0 min (A), 10 min (B), 20 min (C), 40 min (D), and subsequently investigated the quality characteristics. Generally a significant difference was observed between the pumpkin paste treated with and without high-pressure heat. The values of water content, crude protein and crude fiber of the high-pressure heat-treated groups B, C, D were decreased compared with untreated group A. The soluble fiber in experimental group B sweet-pumpkin paste treated with high-pressure heat for 20 min was higher than the control, and the highest value at 2.02. Experimental group D sweet-pumpkin paste treated with high-pressure heat for 40 min was found to have a decreased soluble fiber content relative to the control. The L value for the color of the group A untreated control sweet-pumpkin paste (no high-pressure heating) decreased as the time increased from 10 min to 40 min, with L values of 50.33, 49.46, and 48.06, respectively. The b value for the color of the sweet-pumpkin paste also decreased, showing a significant difference. Taking into account all the results, we chose experimental group B in order to prepare sweet-pumpkin latte. We used 0.2% gum (xanthan gum, locust bean gum, guar gum) as a stabilizer. Sweet-pumpkin latte with xanthan and locust bean gum has a suspension stability effect that lasts 90 min. The L and b values of sweet-pumpkin latte with gums increase and a value decrease compared with the control. In terms of the overall acceptance of the sweet-pumpkin latte, the experimental group with xanthan gum scored the best.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.175-188
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• 2005

This study investigated the effects of silkworm droppings (SWD) added diet feeding on quality characteristics of pork loin meat Pigs were divided into 7 treatment groups (10 pigs/group) and subjected to one of seven treatment diets $(0,\;1\%,\;2\%\;and\; 3\%\;SWD\;for\;4 weeks,\;1\%\;2\%\;3\%$ SWD for 8 weeks, SWD diets; total fed diets) before slaughter. Pork loin were collected from the animals (110kg body weight) slaughtered at a commercial slaughterhouse. Pork loin meat were packaged aerobically and then stored at $4^{\circ}C$ for 2, 5, 8, or 12 days. Samples were analyzed for general composition, texture characteristics and physico-chemical properties. pH value was not significantly different between the control and SWD treatment groups. pH of control and SWD treatment groups were increased as the storage period passed General composition, cooking loss and texture was not significantly different between the control and SWD treatment groups. WHC of SWD treatment group was higher than that of control group. WHC of control and SWD treatment groups were significantly decreased as the storage period passed (p<0.05). Meat and fat color (CIE $L^{\ast}$, $a^{\ast}$, $b^{\ast}$) were no significant differences between the control and SWD treatment groups. $L^{\ast}$ and $b^{\ast}$ value of meat color were decreased as the storage period passed There was a not significantly difference in shear force value among control and SWD treatment groups. Shear force value was decreased significantly during storage in all treatment groups. In all results, dietary SWD-supplementation was not affected in general components, texture characteristics and physico-chemical properties. It is suggested that dietary SWD-supplementation could produce of high quality pork.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.100-106
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• 2011

The physicochemical characteristics of chicken breast were determined to identify the optimal ratio of $CO_2$ and $N_2$ to maintain chicken breast quality during cold storage for 6 d. The mixing ratios of $CO_2$ and $N_2$ were 20:80, 40:60, 60:40, and 80:20, respectively. The pH of the chicken breast packed with 80% $CO_2$ and 20% $N_2$ was lower than that of the control on day 1 (p<0.05). The lightness ($L^*$) of the breast increased with increasing $CO_2$ during storage (p<0.05), whereas no difference was found for redness ($a^*$) and yellowness ($b^*$). A lower volatile basic nitrogen level was found for chicken breasts exposed to higher $CO_2$ levels. Furthermore, lipid oxidation of the chicken breast packed with $CO_2$ decreased with increasing $CO_2$ level, and 40% $CO_2$ significantly reduced 2-thiobarbituric acid reactive substances (TBARS) values on days 1 and 6. The total number of microbes was reduced in chicken breast exposed to more than 40% $CO_2$ during storage days 3 and 6 (p<0.05); however, Escherichia coli was not affected by $CO_2$ level. Coliforms of chicken breast were reduced in the 40% $CO_2$ level on storage day 3. Moreover, tray-packed chicken breast exposed to 40% $CO_2$ did not collapse. These results suggest that 40% $CO_2$ and 60% $N_2$ were the optimal conditions for packaging chicken breasts during cold storage.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.652-658
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• 2012

This study was carried out to identify the ACE (Angiotensin converting enzyme) inhibitory activity of casein hydrolysates for development of anti-hypertensive hydrolysates. Sodium caseinate was treated with six kinds of commercial proteases such as Flavourzyme, Protamex, Neutrase 1.5, Alcalase, Protease M, and Protease S for 8 h individually, and was then treated with the enzyme combination for 4 h at $45^{\circ}C$. The hydrolysate which had the highest ACE inhibitory effect was then hydrolysed successively with three digestive enzymes: pepsin, trypsin, and ${\alpha}$-chymotrypsin, at $37^{\circ}C$ for 4 h under conditions mimicking those of the gastrointestinal tract. UF (ultra filtration) treatment was applied to one of the secondary hydrolysates to determine ACE inhibitory activity. When sodium caseinate was hydrolysed by commercial proteases, the degree of hydrolysis (DH) showed 2.54 to 4.25% and after secondary hydrolysis, DH showed 4.30 to 5.22%. ACE inhibitory activity and $IC_{50}$ values decreased, and inhibition rates increased during hydrolysis. Protamex treatment showed the lowest $IC_{50}$ value ($516{\mu}g/mL$) and Flavourzyme hydrolysate showed the highest $IC_{50}$value ($866{\mu}g/mL$). As the first hydrolysate was treated with Flavourzyme, the ACE inhibitory activity increased. Neutrase hydrolysate had the highest activity with an $IC_{50}$ value ($282{\mu}g/mL$). When Neutrase plus Flavourzyme treatment was hydrolyzed by digestive enzymes, the $IC_{50}$ value ($597{\mu}g/mL$) was decreased statistically (p<0.05). As Neutrase plus Flavourzyme hydrolysate is treated by UF with MW cut-off 10,000, permeate showed $273{\mu}g/mL$ of $IC_{50}$ value, showed no difference, but retentate which has over MW 10,000 showed statistically different $IC_{50}$ value, $635{\mu}g/mL$ (p<0.05).

• Food Science of Animal Resources
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• v.27 no.1
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• pp.8-15
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• 2007

Conjugated linoleic acid (CLA) was chemically synthesized using the alkaline isomerization method of com oil. CLA-TG was synthesized by reaction with sodium methoxide. Five different treatments were devised based on differences in the amount of CLA-TG added into the pressed han. for controls, 10% of pork back fat among the total component was only added without any CLA-TG. For the first treatment, 5% of CLA-TG among the lard component added into the press ham was replaced. For the 2nd, 3rd and 4th treatments, 10%, 15% and 20% of CLA-TG was respectively replaced. Pressed ham manufactured using CLA-TG was vacuum packaged and then stored for 1, 7, 14, 21 and 28 days at $4^{\circ}C$. Samples were analyzed for chemical composition, physico-chemical properties (pH, color), and texture characteristics. Typical chemical composition characteristics (moisture, crude protein, crude fat) were not significantly different between controls and CLA-TG treatment groups. Crude fat content of CLA-TG treatment groups was significantly lower than that of controls (p<0.05). pH values of controls was higher than that of CLA-TG treatment groups. The pH of control and CLA-TG treatment groups increased significantly as the storage period increased (p<0.05). Meat color (CIE $L^*,\;b^*$) of CLA-TG treatment groups was higher than that of controls. $a^*$ values were decreased by replacement of CLA-TG, but appeared to be unaffected by storage length. There was no significant difference in texture between controls and CLA-TG treatment groups. Based on these findings, we conclude that the physico-chemical properties and texture characteristics of manufactured pressed ham were not affected by CLA-TG addition. Also, our results indicate that high-quality pressed ham can be manufactured with CLA accumulation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.343-356
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• 2016

The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5 ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, $^{60}Co$ had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as $^{28}Al$ and $^{24}Na$ had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that the nuclide inventory of a spent nuclear fuel metal cask can be utilized as basic data when decommissioning of a metal cask is planned, for example, for the development of a decommissioning plan, the determination of a decommissioning method, the estimation of radiation exposure to workers engaged in decommissioning operations, the management/reuse of radioactive wastes, etc.

• Applied Biological Chemistry
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• v.8
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• pp.95-100
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• 1967

A quantitative study on the mercury residue in the brown rice of "Paldal", a recommended rice variety in Korea, was carried out by changing the date and frequency of application with different forms of organo-mercury fungicide(PMA), which is used for the control of rice blast. The results are summarized follows: 1) Mercury residues were higher with the emulsion formulation(0.21 ppm) than the dust formulation (0.16 ppm) when they were used for the control of leaf blast on July 13. 2) In case when both of the emulsion and dust formulations were used on July 13 and August 13, respectively, the mrecury residues were lower in the treatment on July 13 (0.216 and 0.16 ppm) than in the treatment on August 13 (0.304 and 0.238 ppm). 3) In an emulsion formulation was applied once on August 13, the mercury residue was 0.304 ppm and its application in twice on July 13 and August 13, the residue was counted 0.32 ppm. In case of dust formulation, the residues were observed 0.238 ppm in a single dose and 0.276 ppm in double application. 4) When the fungicide was applied to the rice plant on August 13, the mercury residues in brown rice, rice bran, and stalk and leaves were 0.304, 0.323, and 0.676 ppm, respectively found in the case of emulsion and in the case of dust formulation, they were 0.238, 0.283 and 0.698 ppm, respectively. The mercury residue, in general, were less in the case of dust than in the case of emulsion formulation and lowered by a single treatment than by two times application and it was also less by treating on July 13 than by treating on August 13.