• The Plant Pathology Journal
• /
• v.37 no.5
• /
• pp.455-464
• /
• 2021

Forty-eight spring barley genotypes were evaluated for deoxynivalenol (DON) concentration under natural infection across 5 years at Harrington, Prince Edward Island. These genotypes were also evaluated for Fusarium head blight (FHB) severity and DON concentration under field nurseries with artificial inoculation of Fusarium graminearum by the grain spawn method across 2 years at Ottawa, Ontario, and one year at Hangzhou, China. Additionally, these genotypes were also evaluated for FHB severity under greenhouse conditions with artificial inoculation of F. graminearum by conidial suspension spray method across 3 years at Ottawa, Ontario. The objective of the study was to investigate if reactions of barley genotypes to artificial FHB inoculation correlate with reactions to natural FHB infection. DON concentration under natural infection was positively correlated with DON concentration (r = 0.47, P < 0.01) and FHB incidence (r = 0.56, P < 0.01) in the artificially inoculated nursery with grain spawn method. Therefore, the grain spawn method can be used to effectively screen for low DON. FHB severity, generated from greenhouse spray, however, was not correlated with DON concentration (r = 0.12, P > 0.05) under natural infection and it was not correlated with DON concentration (r = -0.23, P > 0.05) and FHB incidence (r = 0.19, P > 0.05) in the artificially inoculated nursery with grain spawn method. FHB severity, DON concentration, and yield were affected by year, genotype, and the genotype × year interaction. The effectiveness of greenhouse spray inoculation for indirect selection for low DON concentration requires further studies. Nine of the 48 genotypes were found to contain low DON under natural infection. Island barley had low DON and also had high yield.

• The Korean Journal of Malacology
• /
• v.21 no.1
• /
• pp.19-24
• /
• 2005

This study was undertaken with the intent to describe the influence of water temperature and food concentration on the filtration rates of the Asiatic clam, Corbicula fluminea. The clams were collected at Lake Geumho near Yeongsan river, during March 2001. Food organism, Scenedesmus sp. (KMCC FC-34), was indoor-cultured in f/2 medium, and was used to measure the filtration rate of the clams. Filtration rate of the clams was measured by indirect method. Cell concentrations of food organisms were determined by direct counting cells using the hemacytometer under the light microscope. The filtration rate of the clams increased with water temperature up to circa $25^{\circ}C$. Above this temperature, the filtration rate decreased rapidly. The minimal filtration rate of the clams was recorded at $5^{\circ}C$. Thermal coefficient, $Q_10$ values at low temperature range were much higher than those at high temperature range. These results indicate the asiatic clam is more sensitive in cold water like most of marine bivalves. There was a strong reversed correlation between filtration rate and food concentration. Filtration rate of the clams was reduced as food concentration was increased.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2005.05a
• /
• pp.297-302
• /
• 2005

Physicochemical properties were compared between freeze concentrated and vacuum evaporated milk through colour, brix, viscosity, freezing point and pH measurement. Brix and viscosity in each concentrated milk significantly increased due to solute concentration(p<0.05), and there was not much difference between freeze concentrated and evaporative one. Brix results were numerically modeled with the logarithmic regression: Y=-33.460+18.4513 ${\cdot}$ ln(X), $R^2=0.9798$ and this model was fairly fit to predict the solute concentration in the middle of freeze concentration process. Freezing point significantly decreased according to concentration increment(p<0.05) and there was not the significant difference between freeze concentrated and evaporated one. Whereas, in colour and pH value, there were some differences between freeze concentrated and evaporative milk. Vacuum evaporated milk expressed higher discoloration comparing to freeze concentrated one. In pH values, evaporated milk showed the significantly decreased results comparing to freeze concentrated sample, whereas the pH value of freeze concentrated sample expressed the similar value to the reference milk.

• Preventive Nutrition and Food Science
• /
• v.7 no.2
• /
• pp.219-221
• /
• 2002

N-Nitrosodimethylamine (NDMA) was determined in both domestic Korean and imported beers, from the Netherlands, USA, Japan, Belgium and Germany. Among the 8 kinds of Korean beers, 4 were contaminated with NDMA, and 4 were not. The average concentration of NDMA detected in Korean beers was 0.78 $\mu\textrm{g}$/kg and the maximum NDMA concentration was 5.73 $\mu\textrm{g}$/kg. NDMA was only detected in one imported beer, which had a concentration of 5.29 $\mu\textrm{g}$/kg. Assuming an average concentration of 0.78 $\mu\textrm{g}$/kg NDMA in Korean domestic beer, the average daily intake of NDMA through domestic beer consumption by a typical Korean is approximately 0.58 $\mu\textrm{g}$/person/day.

• Preventive Nutrition and Food Science
• /
• v.4 no.4
• /
• pp.236-240
• /
• 1999

The characteristics of natural lactic acid fermentation of radish juice were investigated at different salt concentrations (0~2%) and temperatures (10~3$0^{\circ}C$). Major lactic acid bacteria isolated from the radish juice fermented at 2% slat concentration were Leuconostoc mesenteroides, Lactobacillus plantarum, and Lactobacillus brevis. The percentage of lactic acid bacteria against total microbe in the fermented radish juice was over 80% at 0~1% salt concentrations, suggesting the possibility of fermentation even at low salt concentration, but was still active even at 1$0^{\circ}C$. The time to reach pH 4.0 during fermentation of juice of 1% salt concentration was 281~301 hrs at 1$0^{\circ}C$ and 50-73 hrs at 3$0^{\circ}C$. The concentrations of sucrose and glucose in the fermented juice were low at high temperatures and were the lowest at a 1.0% salt concentration. However, the content of mannitol showed the opposite trend. Although sour taste, ripened taste, and acidic odor of the fermented juice showed no significant differences among various temperatures and salt concentrations, sensory values of ripened taste and sour acidic were high at high temperatures. The overall quality was the best at 1.0% salt concentration, irrespective of the temperature.

• Korean Journal of Food Science and Technology
• /
• v.51 no.2
• /
• pp.188-191
• /
• 2019

In this study, the poor electro-transformant yield of large DNA in bifidobacteria was improved by increasing the DNA concentration, which was amplified by enhancing electroporation conditions: treating the cell wall weakening agent and cell membrane permeabilizing molecule as well as changing the electrical parameter. In the enhanced conditions, the electroporation frequency increased from 15 to 71 times compared to the initial conditions at the same DNA concentration. As the DNA concentration increased, the difference in the electroporation frequency between the two conditions became greater, and the curve of the enhanced conditions seemed to be saturated with a DNA concentration over $4{\mu}g$. The present study provided a clue to the recovery of the electroporation frequency with large DNA and formulated the relationship between the DNA concentration, the DNA size and the electroporation frequency in bifidobacteria. Therefore, this study will contribute to the expansion of molecular genetic studies of bifidobacteria.

• Food Science and Biotechnology
• /
• v.17 no.2
• /
• pp.379-383
• /
• 2008

Extraction characteristics of garlic and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 26.41% was obtained at microwave power of 146.29 W, ethanol concentration of 63.31 %, and extraction time of 5.88 min. At microwave power, ethanol concentration, and extraction time of 114.84 W, 58.83%, and 1.42 min, respectively, maximum electron-donating ability (EDA) was 72.86%. Maximum nitrite-scavenging ability was 94.62% at microwave power, ethanol concentration, and extraction time of 81.83 W, 2.65%, and 3.83 min, respectively. Superoxide dismutase (SOD) showed maximum pseudo-activity of 49.12% at microwave power of 34.23 W, ethanol concentration of 33.11 %, and extraction time of 4.40 min. Based on superimposition of 4-dimensional RSM with respect to extraction yield, electron-donating ability, nitrite-scavenging ability, and pseudo-activity of SOD, optimum ranges of extraction conditions were microwave power of 0-100 W, ethanol concentration of 40-70%, and extraction time of 2-8 min.

• Korean Journal of Community Nutrition
• /
• v.18 no.3
• /
• pp.223-232
• /
• 2013

The purpose of the study was to investigate the influence of salt (NaCl) recognition threshold and pleasant salt concentrations of Korean rural elderly subjects on preference of salty food as well as food group consumption patterns. The subjects were 213 elderly people (male 71 and female 142) over 65 and under 90 yr of age from Sunchang area. The higher values were found with male subjects in the areas of basic taste recognition threshold and pleasant concentration level of salt. The taste sensitivity scores of male subjects did not decrease with the increasing age, but female subjects exhibited a significant decrease with the age. The major determinant factor of salt preference of the elderly subjects in this study appeared to be personal pleasant concentration of salt rather than salt recognition threshold level and this trend was more evident in males than in females. The subject group of lower salt pleasant concentration i.e. consuming less salt showed the higher number of fruit and fruit juice intakes per week, and higher MNA (define this) scores were implying that they display more desirable nutritional status. Therefore, nutritional education focused on not only a variety of food consumption but also lowering pleasant salt concentration levels is advised to improve the quality of nutrition in the elderly.

• Journal of the Korean Society of Food Culture
• /
• v.29 no.5
• /
• pp.415-420
• /
• 2014

This study was conducted to establish optimum conditions for coagulation of konjac jelly as well as antimicrobial activity by concentration of $Ca(OH)_2$. Hardness, gumminess, and chewiness of konjac jelly increased according to concentration of konjac powder, the key material of konjac jelly. The highest sensory evaluation score was acquired with konjac jelly made with 3% konjac powder. A $Ca(OH)_2$ concentration of 0.4-0.6% as a coagulation agent was optimum for coagulation of konjac jelly. Further, sensory score was highest at a $Ca(OH)_2$ concentration of 0.6%. All populations of bacteria, yeast, and mold in konjac jelly were restrained by $Ca(OH)_2$ in a concentration- dependent manner. Furthermore, all tested microorganisms were strictly restrained at $1.0{\times}10^{-2}$ N of $Ca(OH)_2$.

• Agricultural and Biosystems Engineering
• /
• v.1 no.1
• /
• pp.16-21
• /
• 2000

Measurement of spray deposit is necessary for evaluation of a chemical application technology. However it is not easy and time consuming. A simple method for measuring the deposition amount of spray using a tracer and a spectrophotometer was developed. Various materials were tested to determine an adequate tracer. Food dye was selected as a tracer, because it was cheep and easily treatable. Using NIRS(Near Infrared Reflection Spectrophotometer), a regression curves between maximum absorbance of a solution and concentration of the tracer were obtained. Yellow food dye solution showed a peak of spectrum at 452 nm, and absorbance of peak showed a tendency to increase as concentration increased. Green or pink food dye were tested and judged to be good tracers. However, tracer concentration should not exceed certain limits in order to measure maximum absorption. Using spraying liquid with known tracer concentration and known amount of washing liquid, spray deposit amount on real targets on leaves could be estimated at less than 13% error level.