• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.149-157
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• 1996

A procedure for the determination of Aflatoxins in food and grains which utilizes reversed phased liquid chromatographic (LC) analysis with postcolumn derivatization by an electrochemical cell and determination with a fluorescence detector has been evaluated. The LC mobile phase was water-acetonitrile-methanol (6+2+2) with 1mM KBr and 1 mM HNO3 which gave baseline separation for the four Aflatoxins (AfB1, AfB2, AfG1, AfG2). The electrochemical cell set at 7V, generated bromine and derivatized aflatoxins B1 and G1, The derivatives were detected by the fluorescence detector. The aflatoxins in naturally contaminated corn samples were isolated by three different cleanup procedures: the AOAC method I column(CB method), a rapid filtrate column (Romer's column), and an immunoaffinity column. The final extract were quantitated with fluordensitometric TLC and the LC postcolumn derivatization techniques. The results were quite similar, however the LC technique showed less interferences and could be automated. Samples of corn, raw peanuts, peanut butter and dried dates were also analyzed successfully with this procedure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.1
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• pp.73-79
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• 1990

In order to study on the riboflavin content of common foods for Korean and the rates of destruction of riboflavin during cooking 26 kinds of the foods were selected and 3 kinds of menu were cooked by standardized method. For each food item and menu riboflavin content was measured by AOAC method. The experimental values of 13 kinds of food such as rice oak mushroom carrot squarsh tangle dried large anchovy apple(Fuji) dried laver ramyun pork soybean curd fried soybean curd and danmugi were almost consistent with food compo-sition values. Whereas those of 12 kinds of foods such as cabbage onion potato kimchi beef sausage dried medium anchovy hair tail soybean paste and egg were considerably different from food composition table values, up to now Alaskan pollack maize loaf bread hamburger bread etc have not been analyzed in food composition table, The rates of retention of riboflavin in menu 1, 2, and 3 cooked by standardized method were 24% 69% 46% respectively. The overally retention rate was in inverse proportion to the time of sunlight exposure during cooking.

• Journal of the Korean Professional Engineers Association
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• v.34 no.3
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• pp.68-73
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• 2001

This study was conducted to investigate the possible use of Mulberry leaf as a functional supplement for Mulberry leaves. Chemical characteristics of mulberry leaf were investigated in eleven mulberry varieties, including Suwon, Chongil, Gumseol, Sugae, Yongchun, Hongol, Daeryk, Kaerang, Donae, Chungol and Kuksang20 varieties. The chemical compositions of minerals, amino acids, rutin as flavonol glucoside were analyzed by AOAC methods, HPLC method, amino acid analyzer, respectively. The results are as follows: In case of KukSang Mulberry leaf with spring harvest, the content of general components was crude protein 16.28%, carbohydrate 69.12%, crude fiber 9.15%, crude ash 8.44% and crude fat 2.57% respectively. It is noteworthy that ferrious content of KukSang mulberry leaves contains twice as great as that in other variety of mulberry leaves. The content of alanine was the highest among amino acids in all variety mulberry leaf. Spring leaf contain more utin content than fall leaf, among the variety, spring HongAll leaf rutin contain 260mg/100g as higher than that of fall ChungAll leaf 70mg/100g).

• Journal of the Korea Society of Computer and Information
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• v.7 no.3
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• pp.36-41
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• 2002

This study was carried out develope a ultrasonic transducer displacement generator through 26KHz and 38KHz of the frequency phase modulation on the ultrasonic transducer. This system was producted a power output generation such as 100W, 300W, 400W and 600W. Ultrasonic power output had a change of time. We made use of a Thiram hydration and detected it measurement by the ACAO method. It was to decide the result of ultrasonic power supply for time duration and the result of comparison in the 26KHz & 38KHz by UV/VIS spectrophotometer.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.98-103
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• 2016

Pyropia yezoensis were sampled from Jeonnam in Korea, Jiansu in China and Saga in Japan. Sampled P. yezoensis were analyzed proximate composition by Association official Analytical Chemists(AOAC) method, minerals by ICP-OES and amino acid by amino acid analyzer. Three areas resulted that contents of moisture and crude protein were $8.13{\pm}0.38%$ and $37.25{\pm}1.15%$, and crude lipid, ash and carbohydrate were $2.12{\pm}0.27%$, $7.41{\pm}0.36%$ and $45.06{\pm}1.30%$ respectively. In total minerals, Korea and China were $28300.19{\pm}76.39ppm$and $13945.63{\pm}7.73ppm$, and Japan was $12262.485{\pm}4.38ppm$. Amino acids, Korea and China were $265.28{\pm}0.38mg\;g^{-1}$ and $209.19{\pm}0.19mg\;g^{-1}$, and Japan was $157.61{\pm}0.43mg\;g^{-1}$. Therefore, those substance contents of P. yezoensis are significantly different between cultivation sites. The basic data may used to the environmental and nutritional study of P. yezoensis based on country sites.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.225-231
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• 1993

Total dietary fiber and crude fiber contents were analyzed for 54 different kinds of Korean vegetable foods by AOAC method. On the fresh matter basis, total dietary fiber and crude fiber contents of tested food samples ranged from $1.19{\sim}10.35%,\;0.19{\sim}1.28%$ in cereals, $1.12{\sim}1.81%,\;0.29{\sim}0.64%$ in potatoes, $2.05{\sim}18.14%,\;0.38{\sim}4.42%$, in pulses, $0.99{\sim}7.42%,\;0.35{\sim}2.61%$ in fresh vegetables, $2.28{\sim}41.14%,\;0.97{\sim}20.96%$ in processed vegetables, $0.19{\sim}2.91%,\;0.10{\sim}0.79%$ in fruits, $4.27{\sim}10.83%,\;0.96{\sim}4.62%$ in nuts and seeds, $1.62{\sim}3.94%,\;0.79{\sim}0.89%$ in mushrooms, $28.70{\sim}38.19%,\;2.17{\sim}6.41%$ in seaweeds, and $4.65{\sim}6.67%,\;2.49{\sim}3.44%$ in seasonings, respectively. The ratio of total dietary fiber/crude fiber contents ranged from 2 to 13, showing a wide variation among food commodities, necessitating the analysis of total dietary fiber content for individual food items.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.312-315
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• 2014

The present study demonstrated the development and validation of the method for the quantification of phenol in food using gas chromatography coupled with mass spectrometry (GC-MS). After spiking of internal standard (Phenol-$d_5$) to food, those samples were extracted with organic solvent mixture (acetone : dichloromethane = 1 : 1, v/v) using ultra sonic extractor and cleaned by gel permeation chromatography (GPC) technique. The amount of phenol was determined by GC/MS. To validate the developed method, we evaluated parameters were the selectivity, linearity, accuracy, precision, and recovery. To demonstrate the selectivity of the method, blank samples of rice, corn, and fish(mackerel) were prepared and subjected to GC-MS analysis. To verify the linearity of the method, six different standard concentrations of phenol at 0.01, 0.05, 0.1, 0.5, 1 and 2.5 mg/kg were evaluated. The correlation coefficient ($r^2$) of calibration curve was 0.9999. The recovery rate for phenol standard calculated by internal standard method were 82.2~101.5% for samples fortified with 0.25, 0.50, and 1.0 mg/kg, respectively. Also the repeatability and reproducibility for validation of precision were 0.2~5.5%. According to the result of the validation, this established method was suitable for AOAC guideline. The limit of detection (LOD) for phenol analysis were 0.03~0.1 mg/kg, and the limit of quantification (LOQ) were 0.1~0.3 mg/kg. Therefore, we established the optimal analysis method for determination of phenol in food using GPC and GC/MS.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.297-305
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• 2022

Antioxidants are food additives that extend the shelf life of food products by preventing lipid rancidity caused by active oxygen. They can either be naturally-derived or manufactured synthetically via chemical synthesis. In this study, method validation of five synthetic antioxidants, namely butylated hydroxyanisole, butylated hydroxytoluene, tertiary butylhydroquinone, propyl gallate, and disodium ethylenediaminetetraacetic acid, was performed using a high performance liquid chromatography-ultraviolet visible detector, and the method applicability was evaluated by analyzing foods containing antioxidants. The coefficient of determination (R²) average was 0.9997, while the limit of detection and limit of quantification were 0.02-0.53 and 0.07-1.61 mg/kg, respectively. The intra and inter-day accuracies and precisions were 83.2±0.7%-98.7±2.1% and 0.1%-5.7% RSD, respectively. Inter-laboratory validation for accuracy and precision was conducted using the Food Analysis Performance Assessment Scheme quality control material. The results satisfied the guidelines presented by the AOAC International. In addition, the expanded uncertainty was less than 16%, as recommended by CODEX. Consequently, to enhance public health safety, the results of this study can be used as basis data for evaluating the intake of synthetic antioxidants and assessing their risks in Korea.

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.57-61
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• 2004

Many studies have presented results about the antioxidative and antimicrobial activities of Dandelions (Taraxacum officinale). There has yet to be a study which makes comparisons of nutrients based on the parts of the Dandelion. To identify the nutrient composition by part of dandelion, nutrient contents were analyzed. Dandelions were taken from Songpa-gu in Seoul and the nutrient composition of the flower, leaf and root were measured. The nutrient content of each part was analysed by using the method developed by the Association of Official Analytical Chemists (AOAC). The proximate components(moisture, protein, fat, fiber, ash, and carbohydrates), minerals and vitamins of the dandelion were analysed. The nutrient composition of the dandelions showed many significant differences among the parts when the differences were determined by using Duncan's multiple range test. The leaf contains more protein, ash, Ca, K, Mg, Zn, vitamin A, B$_1$, B$_2$, and C than the other parts. The root has much more fiber, carbohydrate, P and Fe content. The results demonstrate that dandelions could be used as a food source supplement for fiber, Ca, Fe and vitamin B$_2$ which are common nutritional deficiencies in Korea. It is recommended that more research for other bio-functional factors besides nutrients composition is needed to enhance the utilization of the dandelion.

• Journal of the Korean Society of Food Culture
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• v.14 no.2
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• pp.167-175
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• 1999

This study examines the effects of the Korean horticultural foods which are, by traditional wisdom, supposed to contain anti-aging substance. All twenty three kinds of plants are chosen as a sample for the experiment in which the content of three main anti-aging nutrients, -carotene, Vitamin C, and Vitamin E are respectively measured by Nilis, Colorimetric, and AOAC method. The result shows: among the samples, top six plants that contain the most -carotene content are high quality tea(Camellia sinensis), thistle(Cirsium japonicum Var.), Angelica keiskei, mulberry leaves(Morus alba l.), field horsetail(Equisetum arvensa), and carrot(Daucus carota), in order; top four for a Vitamin C contents are low quality tea, mulberry leaves, pine leaves(Pinus densiflora), and high quality tea, in order; top four for a Vitamin E contents are persimmon leaves(Diospyros mongolicum) tea, high quality tea, low quality tea, and pine leaves, in order. Drying or boiling process increases the content of -carotene and Vitamin E in high quality tea, dropwort(Oenanthe javanica), field horsetail, and wild aster(Ligularia stenocephala Marsumum et Koldzumi), while, in case of mulberry leaves, drying process lowers them. Vitamin C content strikingly decreases in heating and drying process.