• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.383-390
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• 1984

The present paper was carried out to elucidate the effect of salt-treatment and the addition of some food additives on the histamine formation and histidine decarboxylase activity in mackerel muscle during storage under different conditions. The histamine formation was inhibited by salting and histamine was hardly formed regardless of the brine concentraction during storage at $5^{\circ}C$. While, during storage at $25^{\circ}C$, the inhibitory effect upon the histamine formation and histidine decarboxylase activity was in proportion to the increase of the brine concentration. The addition of accidulants such as citric acid, malic acid and succinic acid inhibited the histamine formation and histidine decarboxylase activity. Especially, the histamine contents in the muscle added $10\%$ of citric acid and malic acid was below the critical concentration of poisoning for histamine during storage at $25^{\circ}C$ for 10 days. The histamine formation and histidine decarboxylase activity were inhibited by the $10\%$ addition of D-sorbitol, while there was no significant effect in the case of $5\%$ addition. Generally, the histamine content was increased with histidine decarboxylase activity, but didn't reveal the quantitative correlation ship with the enzyme activity.

• Journal of Nutrition and Health
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• v.29 no.7
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• pp.703-712
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• 1996

This study planned to compare the effects of source and amount of dietary n-3 fatty acid, tuna oil and perilla oil, on lipid metabolism and eicosanoids production in Spargue-Dawley strain male rats. Weaning rats were fed 5 different experimantal diets for 4 weeks. (S : beef tallow 50%+sesame oil 50%, T1 : beef tallow 50%+sesame oil 40%+tuna oil 10%, T2 : beef tallow 50%+sesame oil 25%+tuna oil 25%, P1 : beef tallow 50%+sesame oil 40%+perilla oil 10%, P2 : beef tallow 50%+sesame oil 25%+perilla oil 25%) Food intake was higher in T2 group than in other groups, but body weight gain and food efficiency tate were not different among groups. Plasma total lipid and triglyceride were significantly lower in groups fed perilla oil as much as groups fed tuna oil than in S. But tuna oil reduced plasma cholesterol level more than perilla oil. Liver total lipid per unit, cholesterol and triglyceride were not affected by dietary fat sources. Peroxisomal $\beta$-oxidation was higher in T1 and T2 than in P1 and P2. Activities of glucose 6 phosphate dehydrogenase and malic enzyme were lower in T1 and T2 than in group fed sesame oil only. Plasma TXB2 was affected by n-3 fatty acid consumption, and it was lower in perilla oil groups as much as tuna oil groups than in S. But 6-keto PGF1$\alpha$ was not different among experimental groups. The results of this study indicated that tuna oil and perilla oil both decreased plasma lipids, however, the mechanism may be different. And tuna oil and perilla oil had a similar effects on eicosanoids production.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.341-347
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• 2013

This study was conducted to evaluate the effect of early diet dilution with 40% rice hull on growth performance, carcass characteristic and composition of meat-type ducks, and to reveal the possible mechanism for decreased body fat deposition. 160 1-day-old White Peking ducks with initial body weight of $44.5{\pm}1.0$ g were allotted to two treatments with 8 replicate pens per treatment and 10 ducks per pen (5 male and 5 female). Ducks were fed with the experimental starter diets diluted with 0% (control, RH0), 40% rice hull (RH40) during 8 to 14 d of age, respectively. Thereafter, all ducks were fed with grower diet. Ducks fed with RH40 diet from 8 to 14 d of age increased (p<0.05) feed intake, decreased (p<0.05) body weight, body weight gain and adjusted feed intake (excluded rice hull), abdominal fat, skin with fat, and fat content in carcass, and reduced (p<0.05) activities of hepatic malic dehydrogenase, glucose-6-phosphate dehydrogenase and fatty acid synthetase. When diet dilution was withdrawn in the re-fed period from 15 to 42 d of age, full compensatory growth of body weight, breast meat and leg meat weight were attained. However, ducks were still less (p<0.05) carcass fat content and showed continually lower (p<0.05) hepatic lipogenic enzyme activities at the market age in RH40 ducks than the control. These results indicated that diluting diet with 40% rice hull during 8 to 14 d of age might be a suitable method to improve feed efficiency, and to reduce carcass fat deposition in the production of meat-type ducks.

• Nutritional Sciences
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• v.3 no.1
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• pp.25-30
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• 2000

To study the effect of prosomillet (Panicum milaceum) on lipid metabolism, male Sprague-Dawley rats weighing 190$\pm$8g were fed six experimental diets for four weeks. The six diets based on AIN-76 composition consisted of one cholesterol-free(normal) and five 1%(w/w) cholesterol diets, i.e. control, two diets containing additional 0.3 and 0.6%(w/w) methanol extracts of prosomillet and another two diets containing 15 and 30% (w/w) prosomillet powder. There was no difference in weight gains between the groups but relative liver weights increased under the cholestrol diets. Plasma levels of total cholesterol and triglyceride(TG) decreased by 23-27% and by 37-52%, respectively, in the four prosomillet diet groups compared to those of the normal and control groups. Whereas in the liver, only TG levels decreased in the prosomillet diet groups. Fecal excretions of bile acid and cholesterol significantly with methanol extracts of prosomillet. There was a significant increase in the activity of hepatic microsomal cholesterol 7$\alpha$-hydroxylase when feeding 1% cholesterol but prosomillet in the diet, either as in the form of powder or methanol extract, appeared to have only slight additional effects, namely increases in enzyme activity. The activity of liver cytosolic glucose-6-phophate dehydrogenase (G6PDH) tended to be reduced with high cholesterol diets and dropped markedly by 15% using additional prosomillet powder. Those of the liver cytoxolic malic enzyme had a similar tendency to those of G6PDH. The results indicate that certain active components in prosmillet other than fiber have the potential to exert hypolipidemic effects via regulating cholesterol excretions and lipogenesis.

• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.129-133
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• 1993

The effect of different compositions of organic acids on the flavor profile of 10% sugar solution was investigated by the response surface methodology, and the results were used to evaluate the flavor characteristics of lactic acid fermented cereal beverages. A mixture of extruded rice flour (10%) and soymilk (7.8% dry matter) was fermented with Leuconostoc mesenteroides (Sikhae). Depending on the substrate pretreatments, for example, the malt or amylase digestion and the proteolytic enzyme hydrolysis, the sugar and organic acid composition of the product varied. The organic acid composition of the fermented beverages was in the ranges of 0.44-0.55% lactic acid, 0.05-0.09% acetic acid and 0.07-0.09% citric acid, while that of commercial apple juice was 1.59% malic acid and 0.49% acetic acid. The flavor profiles of fermented beverages added with 10% sucrose were compared to those of apple juice and a model mixture containing 0.48% citric acid, 0.39% lactic acid and 0.12% acetic acid in 10% sugar solution. The QDA diagram of fermented beverages approached to that of apple juice, when the substrate was digested by amylase but not by protease.

• Korean Journal of Microbiology
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• v.20 no.4
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• pp.161-172
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• 1982

In order to compare the metabolic activities of methanol utilizing bacteria, Pseudomonas sp. grown in different carbon sources, changes in respiratory activities, prinicipal enzyme activities for the energy metabolism, and the macromolecular compositions of the cells grown on methanol or glucose were measured. 1. The respiratory activity of cells grown on methanol was higher than that of cells grown on glucose, while glucose exhibited the highest $O_2-consumption$ rate among the different respiratory substrates. 2. TRhe activity of hydroxy pyruvate reductase which participates in serine pathway was high in the cells grown on methanol. However, activities of NAD-linked alcohol dehydrogenase, formaldehyde dehydrogenase and formate dehydrogenase were slightly lower in the cells grown on glucose thant on methanol. 4. For succinic dehydrogenase and malic dehydrogenase which take part in TCA cycle, the specific activities were higher in the cells grown on methanol than in those grown on glucose. No activity of glucose-6-phosphate dehydrogenase, which participates in pentose monophosphate shunt, was detectable in the cells grown on either carbon sources. 5. Protein contents of the cells grown on methanol increased relatively compared with those of the cells grown on glucose. However, there are no changes in the contents of carbohydrate and nucleic acid.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1383-1388
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• 2008

Because of high growth rate and large deposition of fat in the abdomen, the chicken has been used as a model organism for understanding lipid metabolism, fattening and growing. In this study, differentially expression of proteins in chicken liver, one of the important organs for lipid metabolism, has been investigated at four different growing stages. After separation of proteins using two-dimensional electrophoresis (2-DE), more than 700 protein spots were detected. Among them, 13 growing stage specific proteins in chicken liver were selected and further investigated by matrix-assisted laser adsorptions ionization-time of flight mass spectrometry (MALDI-TOF MS). Of these, 12 proteins were matched to existing proteins based on a database search. The identified fat-related proteins in this study were fatty acid synthase (FASN) and malic enzyme (ME1). These proteins were more highly expressed at week 32 than at other weeks. In order to confirm the differential expression, one of the proteins, FASN, was confirmed by western blotting. The identified proteins will give valuable information on biochemical roles in chicken liver, especially for lipid metabolism.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.668-673
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• 2013

A recombinant E. coli co-expressing ALA synthase (hemA), NADP-dependent malic enzyme (maeB), and dicarboxylic acid transporter (dctA) was reported to synthesize porphyrin derivatives including iron-containing heme. To enhance the synthesis of bacterial heme, five genes of the porphyrin biosynthetic pathway [pantothenate kinase (coaA), ALA dehydratase (hemB), 1-hydroxymethylbilane synthase (hemC), uroporphyrinogen III synthase (hemD), and uroporphyrinogen III decarboxylase (hemE)] were amplified in the recombinant E. coli co-expressing hemA-maeB-dctA. Pantothenate kinase expression enabled the recombinant E. coli to accumulate intracellular CoA. Intracellular ALA was the most enhanced by uroporphyrinogen III synthase expression, porphobilinogen was the most enhanced by ALA dehydratase expression, uroporphyrin and coproporphyrin were the most enhanced by 1-hydroxymethylbilane synthase expression. The strain co-expressing coaA, hemA, maeB, and dctA produced heme of $0.49{\mu}mol/g$-DCW, which was twice as much from the strain without coaA expression. Further pathway gene amplifications for the porphyrin derivatives are discussed based on the results.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.402-407
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• 1997

This study was conducted to investigate the effects of effects of enprostil, a prostaglandin $E_2$, analogue, on liver triacylglycerol content and factors that regulate liver lipid metabolism in mice. Mice received vehicle or $10{\mu}g$ enprostil/kg body weight intraperitoneally every 6 h, and were killed at 0, 6, 12, 18 and 24 h after the first injection. Enprostil significantly lowered liver triacylglycerol content after 12 h of the first injection. However, the peroxisomal ${\beta}$-oxidation activity was inconsistent with the result of liver triacylglycerol content, because its activity was lovered by enprosil. In another experiment, the effect of enprostil on lipid metabolism in mice was investigated in a short period. Mice received $10{\mu}g$ enprostil/kg body weight intraperitoneally, and were killed after 0, 5, 10, 30 and 60 min. After 30 min, malic enzyme activity was significantly increased by the administration of enprostil compared with the activity at 5 min after. No significant changes in liver carnitine palmitoyltransferase and peroxisomal ${\beta}$-oxidation activities were observed. Plasma free fatty acid concentrations were markedly reduced from 5 through 60 min after the administration of enprostil. Consequently, enprostil suppressive effect on liver triacylglycerol concentration might result from the decreased entry of free fatty acid into liver.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.1
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• pp.163-169
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• 1996

인위돌연변이 유기에 의해 벼로부터 새로운 유전형질체를 개발하기 위하여 낙동벼(모품종)에서 고정된 엽록소 결핍계통(ch mutant)을 선발하였다. 이 계통은 생육 초기부터 엽록소결핍으로 정상엽에 비하여 노란색을 나타내기 때문에 엽록소의 광합성 관여 유전자탐색에 이용가능하다. ch mutant는 전 생육기간 동안 모품종의 51~87% 정도의 엽록소 함량을 보였으나 엽록소 a/b 함량비는 차이가 없었다. ch mutant의 총 엽록소 함량은 모품종의 70.2%였으면 anthocyanin 함량과 flavonol 함량은 각각 285%와 142% 로 높은 함량비를 나타냈다. ch mutant의 카로티노이드 함량은 모품종의 71.1%였고, 크산토필 함량은 56.6%였다. 특히 카로티노이드 성분중 lutein과 neoaxanthin 함량은 각각 모품종의 32%와 34.4%로 매우 낮았으며, $\beta$-카로틴은 차이가 없으나 antheraxsnthin 함량은 106.9%오히려 증가하였다. 개엽상태에서나 군락 상태에서 ch mutant의 반사율과 투과율은 모두 모품종에 비하여 높아 광흡수량은 저하되었다. ch mutant는 모품종에 비하여 출수기가 5일 늦고 간자, 수장, 주당수수, 수당 입수, 임실율, 천립 중 수량에 감소하였다. ch mu-tant와 모푸종은 esterase, phosphogluose isomerase, malic enzyme, hexokinase 동위 효소의 밴드 패턴에서 유의할 만한 차이를 나타내지 않았으나 엽록체 단백질의 경우 주요 밴드인 60KD의 분자량에서 차이를 보였다.