• Korean Journal of Ecology and Environment
• /
• v.40 no.2
• /
• pp.352-356
• /
• 2007

The effects of food concentration (Chlorella vulgaris) and predator (Pseudorasbora parva) density on the distributional pattern of Daphnia pulex was evaluated in observation chambers. It was found that in the chamber with higher food concentration, Daphnia began to aggregate and formed tighter swarms. The close distance between each individual and distance from the center of swarm were observed in higher food conditions however, this distributional pattern was not seen in the chamber without food. Thus it suggests that the food is necessary for the swarming behavior of Boptnia in natural habitat. The swarming developed regardless of predator existence and the predator density did not affect swarming pattern of Daphnia.

• The Korean Journal of Food And Nutrition
• /
• v.27 no.4
• /
• pp.732-741
• /
• 2014

Korean foods have the strengths to addresssome of the health problems of modern man. To assess the properties of Korean noodles, daily value %, DVS, DDS and energy density were compared between many kinds of noodles from around the world. Using a variety of reference materials, a nutritional database of noodles was built for this study. For carbohydrate, lipid, vitamin A, vitamin K, vitamin C, niacin, zinc, and copper, the daily values % of western noodles were significantly higher. Also, the serving size of Korean noodles was significantly small. Comparing the average energy density of the noodles, they showed $1.87{\pm}0.93kcal/g$ (Korean noodles), $2.42{\pm}1.08kcal/g$ (western noodles) and $1.84{\pm}0.84kcal/g$ (other noodles). The dietary fiber, polyphenols, and flavonoids content of the noodles showed no significant difference. Neither DVS nor DDS showed a statistically significant difference. In the Korean noodles, the GMDFV pattern showed a diverse choice of food groups. Korean noodles show a lower energy density, and the small serving size to have favorable for the prevention of obesity. Thus, Korean noodles are an excellent choice in terms of diversity and energy density.

• Journal of Ecology and Environment
• /
• v.36 no.4
• /
• pp.267-271
• /
• 2013

To examine the density effect and food concentration in the competitive output of two Bosmina species, the population growths of Bosmina fatalis were investigated by manipulating the density of B. longirostris and the concentration of algae. The B. fatalis density did not increase in conditions with abundant B. longirostris regardless of the food concentrations. The B. fatalis increased only at low densities of B. longirostris with high food concentrations. Based on the current results, a possible mechanism underlying the seasonal shift from B. longirostris to B. fatalis in Japanese eutrophic lakes will be explored below.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.38 no.5 s.118
• /
• pp.66-73
• /
• 2006

The effects of active packaging on the surface stiffness, mass, volume, density and weight changes of fresh as well as stored eggplant were studied at 11 and $25^{\circ}C$ for 10 days with active packaging material Type 1 and 2 and control. Mass, volume, and surface stiffness of eggplant decreased linearly throughout the storage period regardless of storage conditions; while the mass density showed a reverse trend in the ease of $11^{\circ}C$ storage. Reduction rate of mass, mass density and weight was observed minimum at $25^{\circ}C$ storage temperature with active packaging Type 1. The weight of eggplant decreased at a higher rate in the initial 4 days compared to that in the later period of storage regardless of storage temperature and type of packaging.

• Preventive Nutrition and Food Science
• /
• v.12 no.1
• /
• pp.1-6
• /
• 2007

Colostrum basic proteins (CBP) (MW 1$\sim$30 kDa) were isolated from bovine colostrum using a series of ultrafiltration processes and their effects on osteoblast cell proliferation and bone metabolism were investigated in cell line and animal models. Treatments with CBP (1, 10, 100 $\mu$g/mL) dose-dependently increased cell proliferation of osteoblastic MC3T3 cells. Alkaline phosphatase activity, a marker of osteoblastic phenotype, in the cells was also increased after treatments with CBP in a dose-dependent manner. Significant increases in bone density were observed in femur of ovariectomized rats which were fed a diet with 1% and 10% CBP, compared to rats fed a normal diet. These results suggest that CBP may increase bone mass and density and be useful for the prevention of bone-related diseases.

• Food Science and Biotechnology
• /
• v.17 no.3
• /
• pp.553-557
• /
• 2008

The effects of cheonggukjang and doenjang on bone mineral density, trabecular area and cortical thickness of the tibia, and serum osteocalcin level in ovariectomized rats were investigated. After 4 weeks, bone mineral density, bone trabecular area, the cortical thickness index, and serum osteocalcin level were analyzed. The cheonggukjang and doenjang diet groups showed significant prevention of ovariectomized (OVX)-related body weight gain. Whole body bone mineral density of the OVX group was significantly lower than that of the sham group, whereas the cheonggulgang and doenjang diets resulted in complete restoration of bone mineral density. Trabecular area in the proximal diaphysis and cortical thickness in the distal diaphysis of the tibia were increased significantly in the cheonggukjang and doenjang diet fed groups. The cheonggukjang and doenjang diets significantly reduced serum osteocalcin level in the OVX rats. These results suggest that cheonggukjang and doenjang might have inhibitory effects on osteoporosis, by showing accelerated bone formation in OVX rats.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.22 no.3
• /
• pp.179-199
• /
• 2018

The paper explores a tri-trophic food chain model with density dependent mortality of intermediate predator. To analyze this aspect, we have worked out the local stability of different equilibrium points. We have also derived the conditions for global stability of interior equilibrium point and conditions for persistence of model system. To observe the global behaviour of the system, we performed extensive numerical simulations. Our simulation results reveal that chaotic dynamics is produced for increasing value of half-saturation constant. We have also observed trajectory motions around different equilibrium points. It is noticed that chaotic dynamics has been controlled by increasing value of density dependent mortality parameter. So, we conclude that the density dependent mortality parameter can be used to control chaotic dynamics. We also applied basic tools of nonlinear dynamics such as Poincare section and Lyapunov exponent to investigate chaotic behaviour of the system.

• Food Science and Biotechnology
• /
• v.17 no.1
• /
• pp.151-155
• /
• 2008

Oxidation of low density lipoprotein (LDL) is regarded to play an important role in the development of atherosclerosis. In the present study, salad vegetables with a remarkable DPPH radical-scavenging activity were extracted with methanol, and the methanol extracts were evaluated for the inhibition of $Cu^{2+}$-induced oxidation of human LDL. Separately, the amount of total phenolics was determined colorimetrically using Folin-Ciocalteu reagent. The vegetable extracts, expressing a strong inhibition of LDL oxidation ($IC_{50}$ values, <$100\;{\mu}g/mL$), were from angelica, dandelion, mustard leaf, and water spinach, which contained relatively high level of polyphenol content. Noteworthy, a highly positive correlation was observed between inhibition of LDL oxidation and amount of total polyphenol (p<0.01). Based on these results, it is suggested that salad vegetables, especially angelica, dandelion, and mustard leaf, may be used as easily accessible sources of natural antioxidants, especially in anti-atherosclerosis.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2000.11b
• /
• pp.188-195
• /
• 2000

This study was conducted to measure the moisture content of powdered food using RF impedance spectroscopic method. In frequency range of 1.0 to 30㎒, the impedance such as reactance and resistance of parallel plate type sample holder filled with wheat flour and red-pepper powder of which moisture content range were 5.93∼-17.07%w.b. and 10.87 ∼ 27.36%w.b., respectively, was characterized using by Q-meter (HP4342). The reactance was a better parameter than the resistance in estimating the moisture density defined as product of moisture content and bulk density which was used to eliminate the effect of bulk density on RF spectral data in this study. Multivariate data analyses such as principal component regression, partial least square regression and multiple linear regression were performed to develop one calibration model having moisture density and reactance spectral data as parameters for determination of moisture content of both wheat flour and red-pepper powder. The best regression model was one by the multiple linear regression model. Its performance for unknown data of powdered food was showed that the bias, standard error of prediction and determination coefficient are 0.179% moisture content, 1.679% moisture content and 0.8849, respectively.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.334-343
• /
• 1996

Quality evaluation for food and agricultural products have always been one of the most elusive problems associated with the handling , processing and marketing in a food plant production. In order to detect physical foreign materials in food and agricultural products, non-destructive techniques have been developed for many years. Application of X-ray system to detect physical foreign materials in food and agricultural products could be considered to be a high potential method. Especially , it is impossible to detect internal physical foreign materials by visual inspections. In this study, it was tried to be applied for two different X-ray devices. Soft X-ray system with CdTe sensor and X-ray CT scanner were evaluated for advantage of the detection of non-meltallic foreign materials in food and agricultural products . Though the soft X-ray is not a high energy radiation, it is possible to detect small different density in a material. The CdTe sensor has a high resolution for t e soft X-ray energy region. The density characteristics of foods and foreign material were expressed region. The density characteristics of foods and foreign materials were expressed as a soft X-ray energy spectrum. The energy spectrum was analyzed by a personal computer with a multi-channel analyzer. X-ray CT scanner can provide visual image and analyze by three dimensional information inside food and agricultural products. The X-ray CT scanner using as a medical equipment was used to detect a foreign material. The density characteristics of food and foreign materials in food were tried to be detected by the threshold value on the basis of the CT numbers. The soft X-ray absorption characteristics for acrylin plates and distilled water were obtained and could be found the possibility of detecting a small physical foreign materials such as a plastic wrapping film , a stone and grasshopper in food and agricultural products.