• Horticultural Science & Technology
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• v.33 no.6
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• pp.807-811
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• 2015

This study was conducted to identify the air temperature factors that affect leafing date of mulberry (Morus alba) in Buan, Jeonbuk province. Over the period from 2009 to 2014, the leafing date averaged April 24 (114 Julian days). The earliest leafing date was April 12, in 2014, and the latest leafing date was May 2, in 2011. Yearly variations of daily mean temperature (DMT) and daily maximum temperature (DMxT) were high in the last part of March. There were highly negative correlations between leafing date and degree days of accumulated DMT above 0, 5, and $10^{\circ}C$ in the period from March 1 to April 10. Linear regression equations for estimating the leafing date were y = 153.8 - 0.1886 ${\times}$ ($r^2=0.965^{**}$) and y = 126.2 - 0.2246 ${\times}$ ($r^2=0.825^*$) for the degree days of accumulated DMT above $5^{\circ}C$ in the period from March 1 to April 10 and the last part of March, respectively. Therefore, leafing date of mulberry, which is important for popcorn disease control, is 96.5% predicted by degree days of accumulated DMT above $5^{\circ}C$ in the periods from March 1 to April 10.

• Journal of Food Hygiene and Safety
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• v.18 no.2
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• pp.87-93
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• 2003

This study was performed to investigate aflatoxin reduction resulting from the pre-treatment and the cooking and processing of corn. Aflatoxin was produced by Aspergillus parasiticus ATCC 15517 on a type of corn imported from the United States. The aflatoxin-produced com (AC) was pre-treated in three ways in order to reduce aflatoxin: exposure to sun light for 7 days (SC); ultraviolet irradiation for 56 hours (UC); and washing with water three times (WC). Four kinds of cooking and processing methods (boiling, steaming, baking, and popping) were used to reduce aflatoxin in the AC control, SC, UC, and WC. These treatments produced com gruel, com cakes, com bread and popcorn. The aflatoxin content in the samples was determined by high performance liquid chromatography. The total aflatoxin level of the AC was significantly decreased by sun light and UV (p<0.05), and decreased by washing. After cooking and processing the AC, SC, UC, and WC, and averaging the total aflatoxin levels in the final products, the greatest reduction was found in the com gruel, then the popcorn, then the corn cakes, and the least reduction in the com bread. These results indicate that sunlight and ultraviolet energy could be effective factors in aflatokin degradation in corn before cooking and processing. This study also indicates that boiling, steaming, baking and popping were helpful in reducing the aflatoxin level in the com and that the most helpful factors were exposure time to heat. More research is needed to reduce the aflatoxin level down to below the maximum tolerable level of aflatoxin in foods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.181-185
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• 1999

To compare the composition of volatile flavor components of three different cultivars of rice, Hyangnambyeo (aromatic cultivar), Heugjinjubyeo (pigmented cultivar) and Dongjinbyeo (normal cultivar), the volatile flavor components of brown rice were isolated by Likens-Nickerson simultaneous steam distillation and extraction apparatus. The flavor concentrates obtained were analyzed by gas chromatography and gas chromatography-mass spectrometry. A total of 65 components, including 14 aliphatic aldehydes and ketones, 7 aliphatic alcohols, 8 aromatic alcohols, 13 hydrocarbons, 9 esters, 7 aliphatic acids, and 7 miscellaneous components were identified. The aliphatic aldehydes, which are known as contributors to the overall flavor of cooked rice, were present in larger amounts in Hyangnambyeo than in Heugjinjubyeo and Dongjinbyeo, while the difference in quantity of these components between Heugjinjubyeo and Dongjinbyeo was not remarkable. Hyangnambyeo and Heugjinjubeyo contained 562 ng and 259 ng of 2-acetyl-1-pyrroline per gram of brown rice based on dry weight, respectively, which is a key compound contributing to the popcorn-like aroma in aromatic rice. Dongjinbeyo contained about 6 ng.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.115-120
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• 1998

This Study was performed to investigate the contents of aflatoxin $B_{1}$ in cereal, pulse, nuts and these products of domestic and import. These results were as follows. 1. Average concentration(in ${\mu}g/kg$) of aflatoxin $B_{1}$ in domestic foods were 2.6 in cereal, 3.9 in pulse, 4.2 in nuts and 1.4 grain products. The contents of aflatoxin B$_{1}$ in pulse and nuts were much higher than those of cereal and grain products. But their values were still within $10{\mu}g/kg$ the maximum residual level of aflatoxin $B_{1}$ for food of Korea. 2. Average contents of aflatoxin $B_{1}$ in import foods were 4.8, 5.4, 6.0, $3.8{\mu}g/kg$ for cereal pulse , nuts and popcorn & peanuts butter, respectively. And these values were found to be below the maximum residual level ($10{\mu}g/kg$) of aflatoxin $B_{1}$ for food of Korea. 3. The concentration of aflatoxin $B_{1}$ in 2 samples of domestic and 9 samples of import foods were over the tolerance limit for aflatoxin $B_{1}$ in food of Korea. Therefore, the hygienic managements of the foods should be required during storage and circulation at market.

• Journal of the Korean institute of surface engineering
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• v.32 no.6
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• pp.647-657
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• 1999

Due to the inherently poor adhesion strength of Cu-based leadframe/EMC (Epoxy Molding Compound) interface, popcorn cracking of thin plastic packages frequently occurs during the solder reflow process. In the present work, in order to enhance the adhesion strength of Cu-based leadframe/EMC interface, black-oxide layer was formed on the leadframe surface by chemical oxidation of leadframe, and then oxidized leadframe sheets were molded with EMC and machined to form SDCB (Sandwiched Double-Cantilever Beam) and SBN (Sandwiched Brazil-Nut) specimens. SDCB and SBN specimens were designed to measure the adhesion strength between leadframe and EMC in terms of critical energy-release rate under quasi-Mode I ($G_{IC}$ ) and mixed Mode loading ($G_{C}$ /) conditions, respectively. Results showed that black-oxide treatment of Cu-based leadframe initially introduced pebble-like X$C_2$O crystals with smooth facets on its surface, and after the full growth of $Cu_2$O layer, acicular CuO crystals were formed atop of the $Cu_2$O layer. According to the result of SDCB test, $Cu_2$O crystals on the leadframe surface did not increase ($G_{IC}$), however, acicular CuO crystals on the $Cu_2$O layer enhanced $G_{IC}$ considerably. The main reason for the adhesion improvement seems to be associated with the adhesion of CuO to EMC by mechanical interlocking mechanism. On the other hand, as the Mode II component increased, $G_{C}$ was increased, and when the phase angle was -34$^{\circ}$, crack Kinking into EMC was occured.d.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.79-88
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• 2015

English vowels are difficult to teach and learn because both teachers and learners cannot show or see shapes of vocal tract inside their own mouth cavities. The aim of this study is to examine what kind of changes occur in production and perception of English vowels by college students before and after lessons in order to provide fundamental materials for teaching students English vowels. Fifteen volunteer female students attending an English phonetics course participated in the lessons for one and half a month period. Formant values of vowels produced and perceived before and after the lessons were obtained using Flying Popcorn and Praat. Results showed that a produced vowel space after the lessons was greater than that before the lessons with no significant difference. Distances between some adjacent corner vowels were too close to be distinguished. Secondly, perceived vowels before and after the lessons were almost the same. Here again, some adjacent vowels were closely spaced. Thirdly, three groups which were divided by the length of the distance between the vowel /i-${\ae}$/ showed similar patterns in their perception and production. Generally the vowel space expanded from [u] to [${\ae}$]. The author concluded that there was no drastic improvement of vowel perception and production within a short period of time. Further studies would be desirable to examine how successful any long-term English vowel lessons would be and which methods should be taken to evaluate students' achievements proposed here.

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.281-287
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• 1997

We have reported a sensitive, specific and simple direct competitive ELISA method to detect aflatoxin in agricultural commodities. We evaluated the ELISA for practical use to detect aflatoxins contaminated in the domestic and foreign agricultural commodities. The detection limits of the direct ELISA for residual aflatoxins in rice, pine nuts, corns, almonds, bean nuts, and pistachio were 10 ppb and in peanuts and cashew nuts were 20 ppb, which were elucidated from the standard curves of ELISA for aflatoxin fortified into the agricultural commodities. Residue studies of naturally contaminated aflatoxins in the agricultural commodities were also carried out by using direct ELISA. As the results of the studies, it was revealed that there were no residues of aflatoxins in 20 rice samples produced in south Korea, 20 pine nut samples in south Korea (9 samples), USA (1 sample) and China (10 samples), each of 20 almond, pistachio and bean nut samples in USA. However, aflatoxin residues were detected in corn samples imported from north Korea (350∼585 ppb in 2 of 3 samples), from USA (109*326 ppb in 6 of 6 samples) and domestic corns (61-326 ppb in 7 of 17 samples). The toxins were contaminated in corn imported from USA for popcorn (17∼20 ppb, in 3 of 10 samples) whereas no residues were detected in corn from south Korea and China. In case of cashew nuts imported from India, 11.4∼23.1 ppb of aflatoxins were detected in 4 from 20 samples. Most of the contaminated foods were harvested before 1995. Thus, hygienic managements of the foods should be required during storage and circulation at market.

• Journal of Nutrition and Health
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• v.42 no.3
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• pp.291-299
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• 2009

This study was carried out to examine the proportion of fatty acids and contents of trans fatty acid in commercial processed foods in Jeon-Buk area. Contents of trans fatty acid in bakery products ranged from 0.2% to 1.0% per 100 g food. Especially garlic bread and pastry contained the highest amount. Popcorns contained trans fatty acid from 0.0% to 13.4%. Among them, instant popcorns for microwave contained the highest amount, while trans fatty acid was hardly detected in popcorns for theater. And trans fatty acid detected in popcorns was mostly in the form of 18 : 1 trans. The content of trans fatty acid in pizza was nearly 0.2%. Amounts of saturated fatty acid and unsaturated fatty acid were similar between each type of pizza and frozen pizza. Fritters such as fried chickens and vegetables contained trans fatty acid less than 0.2% per 100 g food.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.55-59
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• 2001

Pressure-puffing system or extruder has been used to puff rice kernel or rice flour. Most of the study on rice puffing were the effect of process conditions such as moisture content and heating temperature on physical and chemical characteristics of popped rice. The study on mechanism and development of instant puffed rice like popcorn has been limited. Extruded waxy rice pellets were puffed in a microwave oven after drying and conditioning. Extruded pellets were formed with extrusion conditions of $20{\sim}27%$ moisture content, 2.76 MPa $CO_2$ gas injection pressure and 200 rpm screw speed. Under these conditions, puffed waxy rice pellets in microwave oven had low density and soft texture. Density and texture of puffed waxy rice pellet could be optimized by control of moisture content, $CO_2$ gas injection pressure and screw speed that affect significantly when puffing extruded waxy rice pellet.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.352-359
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• 2020

BACKGROUND: The mulberry cultivars 'Daeshim' and 'Shimgang' were developed in RDA in 2014 and 2017, respectively. 'Daeshim' yields a fruit size bigger than that of other varieties and has a productivity of over 70%, whereas 'Shimgang' has a high yield and a special characterization against the mulberry popcorn disease. In our study, a compositional comparison of these popular cultivars in Korea was undertaken to explore the nutrient profiles of mulberry fruit and promote the development of the rich minerals and flavonoids in mulberry fruit as performing each other irrigation time. METHODS AND RESULTS: These two cultivars were collected from the Sericulture and Apiculture Division, RDA, in Korea to investigate their amounts, weights, minerals, and flavonoid content using each other instrument. After 6 h of irrigation treatment, the amount of fruit (kg/tree) from Daeshim and Shimgang increased by 17.5 and 15.2 kg/tree, respectively. The total flavonoid content from Daeshim and Shimgang was determined to be 132.9 mg and 36.3 mg, respectively, after the 6 h irrigation treatment. CONCLUSION: Appropriate irrigation treatment methods such as water scheduling and volume will help increase fruit quantities and farmer incomes. It would be interesting to conduct further in-depth research on these fruits so that consumers can benefit from them as a food additive.