• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.64-70
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• 2011

Nitrate reductase (NR) is activated by nitrogen sources (${NO_3}^-$ and ${NH_4}^+$) and irradiance. This study investigated the effects of these factors on the NR activity of Ulva pertusa (Chlorophyta) and Ecklonia cava (Phaeophyta). In addition, the ammonium (${NH_4}^+$) and nitrate (${NO_3}^-$) uptake rates of the two species were examined. U. pertusa took up most of the ${NO_3}^-$ and ${NH_4}^+$ in the medium during a 3hour incubation, while E. cava had a relatively high uptake rate after 3 hours. The NR activities of the two species were affected by the nitrogen source and irradiance and were highest when they were exposed to ${NO_3}^-$-rich medium and high irradiance. However, the patterns of NR activity differed between the two species. In ${NO_3}^-$-rich medium and high irradiance, U. pertusa achieved the highest NR activity ($2.01{\pm}0.07\;{\mu}mol$ ${NO_2}^-$ $g^{-1}$ DW $h^{-1}$) within the first 3 hours and then this activity decreased drastically. By contrast, the NR activity of E. cava ($0.36{\pm}0.04\;{\mu}mol$ ${NO_2}^-$ $g^{-1}$ DW $h^{-1}$) was constant for 12 hours. When exposed to darkness, the NR activity of U. pertusa decreased dramatically, while that of E. cava increased gradually for 12 hours. Therefore, E. cava is able to maintain NR activity during the dark because of its adequate carbohydrate reserves and substrate.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.7-15
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• 2015

In this study, the thermal treatment yam (Dioscorea batatas DECNE.) was analyzed for its proximate and nutritional compositions including mineral, vitamin, amino acids and fatty acids. Thermal treatment yam is mainly consisted of carbohydrate (70.3%) with small amounts of crude protein (15.8%), crude ash (5.1%) and crude fat (1.6%). It was found to be a good source of essential minerals such as K (1100.2 mg/100 g), Mg (99.4 mg/100 g), Ca (54.8 mg/100 g) and Na (44.9 mg/100 g) but Zn (4.8 mg/100 g) and Fe (0.2 mg/100g) content was low. Little amounts of vitamin E (8.3 mg/100g), vitamin C (3.5 mg/100g) and vitamin B1 (2.1 mg/100g) could be found. The amino acid analysis revealed that the yam was superior with respect to serine (1454.2 mg%), lysine (684.6 mg%) and histidine (684.6 mg%). Essential amino acids were calculated to be 2849.3 mg%. The amino acid profiles showed that thermal treatment yam is limiting in isoleucine and phenylaline. Linoleic acid was the most predominant fatty acids with the value of 47.3% followed by palmitic acid (24.7%) and oleic acid (12.7%). And the unsaturated fatty acids including oleic acid and linoleic acid were present in big quantities in thermal treatment yam.

• Ocean and Polar Research
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• v.34 no.3
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• pp.297-304
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• 2012

Pylaiella littoralis was collected in the Chuuk lagoon of the Federated States of Micronesia (FSM). The FSM has a variety of coral reef ecosystems, which provide essential materials, such as minerals, vitamins, essential amino acids, for marine organisms. In this study, the antioxidant activities of ethanol and enzymatic extracts of P. littoralis were evaluated by measuring their scavenging activities on DPPH free radical, Alkyl radical, hydroxyl radical and cell viability. The enzymatic extracts were hydrolyzed to prepare water soluble extracts by using five carbohydrate degrading enzymes (AMG, Celluclast, Termamyl, Ultraflo, and Viscozyme) and five proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase, and Protamex). As a result, the enzymatic extracts prepared by Flavourzyme, Ultraflo, and Kojizyme exhibited the greatest effects in DPPH free radical, alkyl radical scavenging activity and cell viability. Also, these enzymatic extracts had a higher antioxidant effect then commercial antioxidants in DPPH free radical and Alkyl radical scavenging activity. This study suggests that P. littoralis might be a useful source of natural antioxidants for the development of dietary supplements.

• Journal of Community Nutrition
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• v.4 no.1
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• pp.12-21
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• 2002

This study was conducted to investigate the dietary intake, anthropometric data, and association between two factors and main food sources contributing macronutrients for overweight and obese females. Subjects were 85 adult females (overweight : 28, obese 57) where mean age was 38.7y. The results are summarized as follows. Mean fat percent, BMI, obesity rate were 29.3, 23.9 and 15.1%, respectively for overweight women and 32.7, 28.3, 36.4%, respectively for obese women. There were significant differences for most of the anthropometric data between groups. Fat percent for all subjects was significantly correlated with weight, waist circumference, hip circumference, mid arm circumference or skinfold thickness for the triceps, subscapular and suprailiac (p < 0.001). The parameter which showed the highest correlation coefficient (r=0.6156) with fat Percentage was the waist to hip ratio. Any significant differences were not found in dietary intake of nutrients or in diet composition between groups. The mean energy intake was 2090.1kcal (104% of RDA) for overweight women and 2113.0kcal (106% of RDA) for obese women. PFC ratio for overweight was 17 : 24 : 59 and 18 : 23 : 58 for obese subjects, which can be regarded as higher fat and lower carbohydrate percentages compared to recommended PFC ratio (15 20 65) .4) Fat intake was positively correlated (r : 0.2301, p < 0.05) with the triceps skinfold thickness, protein intake was also positively correlated with waist circumference (r=0.2668, p < 0.05) or fat weight(r: 0.2406, p < 0.05) .5) The main food items that contributed to energy intake for overweight or obese subjects were similar (rice, pork, bread, grapes, barley) except com oil in overweight or instant noodle for obese group. The subjects in this study were taking less energy from rice and more energy from pork and bread than women from 98 National Health and Nutrition Survey. Because there were no significant differences of dietary data between overweight and obese group, further investigation considering basal metabolic rate or activity would be needed.

• Applied Biological Chemistry
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• v.6
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• pp.8-13
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• 1965

Korean MEJUES were prepared by means of ordinary, Improved and compromised methods, and analyses of the changes in various chemical compositions of the Soy-sauces throughout the fermentation period of 10 weeks. Now, their result, are as the following as. (1) In all of the Soy-sauces under study the content of organic acids showed a slight increase upto 4 week, and a marked increased after this period. (2) In all of the soy-sauces the total nitrogenous content indicated a rapid increase until 4 weeks, and a slower increase after this. (3) In all of the soy-souses, the content of free amino acids displayed a liner proportional increament until 8 weeks and then slower increose. (4) In all of the soy-souses the content of reducing sugars indicated a slight increase until 4 weeks, and after this it showed a rapid decrease until 4 weeks, in the improved soy-souses and, then maintained an almost flat curve. In the ordinary and Compromised soy-souses there was a rapid decrease in reducing sugars until 6 weeks, and then an almost 리at curves. (5) In the ordinary soy-sauce the SAMWOL-ZANG-BUB(soy-sauce prepared in March) is considered to be based on a comparatively scientific ground during the fermentative period. (6) In order to improve the taste in ordinary soy-sauce it is favorable to delay the period of preparation. The adequate period appears requires 8 weeks at least. Accordingly it is recommended to mix the materials with carbohydrate source. (7) In the improved soy-sauce according to the SAMWOL-ZANG-BUB of ordinary soy-sauce it is thought that 8 weeks were adequate for the fermentation. (8) The compromised method may be recommended for the improvement of nomemade soy-souce, and it may be also superior to the ordinary soy-sauce in quality.

• Korean Journal of Community Nutrition
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• v.17 no.4
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• pp.429-439
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• 2012

The purpose of this study was to evaluate nutrients intakes, glycemic index (GI), glycemic load (GL) according to body mass index (BMI) in female college students (n = 320). The study subjects were divided into 3 groups based on their body mass index, an underweight group (BMI < 18.5 kg/$m^2$, n = 55), a normal group (18.5 kg/$m^2$ ${\leq}$ < 23 kg/$m^2$, n = 231), and an overweight group (23 kg/$m^2$ ${\leq}$ BMI < 25 kg/$m^2$, n = 34). The food and nutrition intake data obtained by administering a 3-day food record and were analyzed by using Can pro 3.0 software. Anthropometric measurements were collected from each subject. Body weights and BMI of the underweight group were 45.9 kg, 17.6 kg/$m^2$, those of the normal group were 53.8 kg, 20.5 kg/$m^2$, and those of overweight group were 62.6 kg, 23.8 kg/$m^2$, respectively. The mean daily dietary GI of underweight, normal and overweight groups was 66.2, 65.8 and 66.5, respectively. These differences were statistically non-significant. The mean daily dietary GL of underweight, normal and overweight groups were 159.2, 149.4, and 148.9, respectively. The major food source of dietary GI and GL was rice in the three groups. Dietary GI and GL were not significantly correlated with obesity when adjusted for energy, carbohydrate and dietary fiber intake.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.29-37
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• 2017

Defatted bovine liver (DBL) is a potential source of protein and minerals. Supercritical carbon dioxide ($SC-CO_2$) and a traditional organic solvent method were used to remove lipid from bovine liver, and the quality characteristics of a control bovine liver (CBL), bovine liver defatted by $SC-CO_2$ ($DBLSC-CO_2$) at different pressures, and bovine liver defatted by organic solvent (DBL-OS) were compared. The $DBLSC-CO_2$ samples had significantly higher (p<0.05) protein, amino acid, carbohydrate, and fiber contents than CBL and DBL-OS. There was a higher yield of lipid from CBL when using $SC-CO_2$ than the organic solvent method. SDS-PAGE analysis demonstrated that the CBL and $DBLSC-CO_2$ had protein bands of a similar intensity and area, whereas DBL-OS appeared extremely poor bands or no bands due to the degradation of proteins, particularly in the 50 to 75 kDa and 20 to 25 kDa molecular weight ranges. In addition, $DBLSC-CO_2$ was shown to have superior functional properties in terms of total soluble content, water and oil absorption, and foaming and emulsification properties. Therefore, $SC-CO_2$ treatment offers a nutritionally and environmentally friendly approach for the removal of lipid from high protein food sources. In addition, $SC-CO_2$ may be a better substitute of traditional organic solvent extraction for producing more stable and high quality foods with high-protein, fat-free, and low calorie contents.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.710-721
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• 2020

This study dealt with the use of quinoa flour (QF) or teff flour (TF) as partial beef fat replacers in the formulation of emulsion-type sausages. A control (C) group was manufactured with 20% beef fat, while the other three groups were formulated with 10% beef fat plus 5% QF (Q), 5% TF (T), and 2.5% QF+2.5% TF (QT). Water-holding capacity of the emulsions was higher in Q (81.81%), T (82.20%), and QT (84.10%) samples than in C (64.83%) samples. Total expressible fluid and expressible fat were the lowest in Q and T samples, indicating the highest emulsion stability of those groups. Incorporation of QF and TF into formulations increased moisture and carbohydrate contents while decreased fat and energy values. Besides, the use of QF was effective to increase protein and dietary fiber contents. T sausages had lower luminosity (L^⁎) and higher yellowness (b^⁎) than C sausages, whilst Q sausages did not result in significant color changes. Higher cook yield values were recorded in Q (97.96%), T (98.21%), and QT (98.15%) samples compared with C (96.44%) samples. Inclusion of QF and TF to formulation led to lower hardness and gumminess, while utilization of TF was also effective to decrease chewiness. Consequently, healthier emulsified sausages were obtained by the inclusion of QF or TF that could decrease the fat content more than 50% without sacrificing overall quality, bringing advantages by quinoa over teff for increasing nutritional value and leading minimal modifications on color and texture.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.143-152
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• 2001

Korean-style fermented soybean paste (KFSP), Doenjang, is a traditional food that is consumed as a protein source in Korea. Recently, efforts to identify biolgocial response modifiers (BRMs) have been focused on food products. Accordingly, this study which isolated abiologically active substance form KFSP, named KFSP-BRM, ws defined to be aheat-stable carbohydrate with a molecular weight of 2,000 kDa. The biological activity of KFSP-BRM was not inactivated by treatment with an anti-LPS antibody. The oral as well as intraperitoneal treatment of mice with KFSP-BRM significantly enhanced the number of B cells expressing surface significantly enhanced the number of B cells expressing surface immunoglobulins (IgM and IgG). Subsequently, an increased level of immunoglobulins in the sera was also observed. In vitro. KFSP-BRM was found to upregulate the production of interleukin-1 (IL-1) and IL-6 by mactro phages and B cells but not the production of IL-2 by T cells. In conclusion, these data demonstrate the presence of a BRM in KFSP, which may provide an additional benefit to those consuming it is a food. KFSP-BRM is a novel B cellmitogen distinct from fresh soybean lectin or B cell mitogens, such as LPS and Streptococcus protein A. The major biological effects of KFSP-BRM would appear to be anincreased production of IL-1 and IL-6 by macrophages and B cells, thereby enhancing the function of mature B cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.117-126
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• 1984

Aflatoxins are toxic and carcinogenic secondary metabolites which are produced by trains of A. flavus and A. parasiticus during their growth on foods and feedstuffs. Aflatoxins are a group of closely related heterocyclic compounds of which $B_1$, $B_2$, and $G_2$ are the major members. Aflatoxins are synthesized via a polyketide pathway in which the general steps are acetate, an-thraquinones, xanthone and aflatoxins. Aflatoxin formation is favored by high moisture or high $a_w$(0.95${\sim}$0.99). The limiting $a_w$ for aflatoxin production on agricultural commodities is 0.83. Optimum temperature for aflatoxin production by the molds is $25{\sim}30^{\circ}C$ and the incubation time for the maximum production of the toxin is 7${\sim}$15 days. The limiting temperatures for aflatoxin production are ${\leq}7.5^{\circ}C\;and\;\geq40^{\circ}C$. Cycling temperatures may or may not stimulate aflatoxin production depending on the amplitude of cycling, substrate and strains of molds. Aflatoxin pro-ducing molds are aerobic organisms and thus have a requirement for oxygen. A decreasing $O_2$ concentration and/or increasing concentrations of $CO_2$ or $N_2$ depress the mold growth and aflatoxin formation. A. flavus grows competitively or associatively in the presence of other microorganisms and occasionally loses the competition with other microorganisms. Some lactic acid bacteria have been shown to reduce growth and aflatoxin production by A. parasiticus. Carbon source is the most important nutritional factors affecting aflatoxin formation by the molds. Sucrose, fructose and glucose are the most favorable carbon sources. Food substrates of plant derived products which have high carbohydrate content such as agricultural commodities and their products are most vulnerable to contamination by aflatoxins.