• 한국축산식품학회지
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• 제41권4호
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• pp.731-738
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• 2021

Herein, a novel analytical method using a high-performance liquid chromatography-fluorescence detector (HPLC/FLD) is developed for rapidly measuring an L-carnitine ester derivative in infant powdered milk. In this study, solid-phase extraction cartridges filled with derivatized methanol and distilled water were used to effectively separate L-carnitine. Protein precipitation pretreatment was carried out to remove the protein and recover the analyte extract with a high recovery (97.16%-106.56%), following which carnitine in the formula was derivatized to its ester form. Precolumn derivation with 1-aminoanthracene (1AA) was carried out in a phosphate buffer using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) as the catalyst. Method validation was performed following the AOAC guidelines. The calibration curves were linear in the L-carnitine concentration range of 0.1-2.5 mg/L. The lower limit of quantitation and limit of detection of L-carnitine were 0.076 and 0.024 mg/L, respectively. The intra- and interday precision and recovery results were within the allowable limits. The results showed that our method helped reduce the sample preparation time. It also afforded higher resolution and better reproducibility than those obtained by traditional methods. Our method is suitable for detecting the quantity of L-carnitine in infant powdered milk containing a large amount of protein or starch.

• 한국축산식품학회지
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• 제43권6호
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• pp.949-960
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• 2023

This research aimed to validate a high-performance liquid chromatography method for the quantitative determination of bixin and norbixin in various foods. The Diode Array Detector (495 nm) technique was used. Method was validated for specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy, and the measurement uncertainty was assessed. The calibration curve showed excellent linearity (r²≥0.9999) over the tested concentration range of 0.2-25 mg/L. The LOD and LOQ were 0.03-0.11 and 0.02-0.05 mg/L for bixin and norbixin, respectively. The intra-and inter-day accuracies and precisions were 88.0±1.3-97.0±0.5% and 0.2%-2.6% relative SD (RSD) for bixin and 88.2±0.8-105.8±0.8% and 0.3%-2.7% RSD for norbixin, respectively. Inter-laboratory validation for accuracy and precision was conducted in three laboratories, and these results all met the AOAC guidelines. In addition, the relative expanded uncertainty (<22%) satisfied the CODEX recommendation. Furthermore, products distributed in Korea were monitored for annatto extracts using the proposed method to demonstrate its application. The developed analytical method is reliable for quantifying bixin and norbixin in various foods.

• 분석과학
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• 제36권5호
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• pp.205-215
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• 2023

In the present study, an analytical method was proposed for detecting trifluralin in aquatic products at trace concentrations. The method employed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) and gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) as the sample preparation and measurement, respectively. The effect of the aqueous phase volume used in the QuEChERS was demonstrated, and the ratio of 10:10 (mL) between water and acetonitrile phase was used for 5 g of sample. Besides, dSPE using C18 and primary-secondary amine (PSA) was applied to remove the potential interferences from the food matrices, indicating no remarkable analyte loss. The linear range was built up from 0.50 ㎍ L^-1 to 3.0 ㎍ L^-1 (R² = 0.9993). Other criteria, i.e., repeatability (RSD_r = 0.86-1.96 %), reproducibility (RSD_R = 1.09-2.01 %), and recovery (over 90 %), were in accordance with Appendix F of AOAC (2016) for method performance. Although no trifluralin was detected for the commercial samples (fish, shrimp, and breaded shrimp), the spiked samples performed favorable recoveries and precision.

• 동아시아식생활학회지
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• 제15권1호
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• pp.71-77
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• 2005

Proximate analysis, mineral and fatty acid composition of three conventional domestic soybean cultivars and two imported ones including glyphosate-tolerant HS2906 were evaluated by AOAC method, ICP-AES and gas chromatography. There were several differences in the proximate analysis among three conventional domestic soybean cultivars ; higher crude fat in the cultivar Hwanggumkong, higher crude protein in Pungsankong, and higher carbohydrate and crude ash in Duyukong. The ranges of contents of proximate components of domestic cultivars were similar to the data previously reported. There were no significant differences in proximate analysis between conventional soybean WS82 and glyphosate-tolerant HS2906 ; 23.55-23.90% of crude fat, 34.22-35.55% of crude protein, 6.25-6.45% of crude ash, and 25.35-26.47% of carbohydrate. The mineral and fatty acid compositions of HS2906 were similar to those of conventional soybeans previously reported.

• 동아시아식생활학회지
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• 제16권6호
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• pp.740-746
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• 2006

The proximates, vitamin C, minerals, and fatty acids of five potato cultivars were evaluated by AOAC methods, the hydrazine method, ICP-AES, and gas chromatography, respectively. The proximate analyses; vitamin C, reducing sugar, and soluble solid contents; and mineral and fatty acid compositions were significantly different among the five cultivars. The Superior cultivar contained a higher carbohydrate content and higher Ca/P ratio and lower levels of crude protein and Na. The Atlantic cultivar contained significantly higher amount of energy, carbohydrate, reducing sugar, vitamin C, SEA, and MUFA, and significantly lower amount of minerals and PUFA. The Shepody cultivar contained significantly higher amount of carbohydrate and MUFA, and significantly lower amount of soluble solid, vitamin C, and SFA. In addition, the P, Fe, Mg, Cu, and Al levels were significantly higher in Shepody, and Zn content was significantly lower. The Jopung cultivar contained significantly higher levels of moisture and Na, and significantly lower levels of soluble content, reducing sugar, carbohydrate, crude protein, and fat. Finally, the Namsuh cultivar contained significantly higher amount of soluble solid, crude protein, K, Mg, and Al, and significantly lower amount of reducing sugar.

• 한국축산식품학회지
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• 제37권5호
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• pp.787-791
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• 2017

Panax ginseng marc is produced from fresh ginseng roots during processing and is generally treated as industrial waste. The primary aim of this study was to improve its utilization in the dairy industry as a potential high-value resource. Yogurt was prepared from 11% skim milk powder, 0.1% pectin, 10% sucrose, and ginseng marc ethanol extract (GME, 0.5% and 1.0%) in milk, and was inoculated with a 0.02% yogurt culture (Lactobacillus acidophilus, Bifido-bacterium longum, and Streptococcus thermophilus). After fermentation at $40^{\circ}C$ for 6-8 h, the physicochemical properties of samples were analyzed by the AOAC, Kjeldahl, and Soxhlet methods. Sensory evaluation was performed based on consumer acceptability scores with a 7-point scale, and antimicrobial effects were measured by the agar plate method. The moisture, crude protein, crude fat, and ash contents of yogurt supplemented with 1% GME were $85.06{\pm}0.06%$, $4.41{\pm}0.01%$, $4.30{\pm}0.05%$, and $0.81{\pm}0.03%$, respectively, with no significant changes noted from those of yogurt without GME (control), except for an increase in the crude fat content. The sensory scores of color, flavor, texture, overall taste, and overall acceptance of yogurt supplemented with below 1% GME did not differ significantly (p<0.05) to those of the control yogurt. In addition, the growths of Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Escherichia coli, and Enterobacter sakazakii were inhibited during fermentation and storage. These results suggest that GME could be used in dairy products as a supplement and in the food industry as an antimicrobial material.

• 한국식품조리과학회지
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• 제32권5호
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• pp.575-584
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• 2016

Purpose: Nurungji is a traditional Korean food made by yellowish scorched rice. After getting gelatinization of rice, a thin crust of scorched rice will usually be left in the bottom of the traditional cooking pot. In this study, physicochemical characteristics and antioxidant properties of five commercial nurungji products (CNP1, CNP2, CNP3, CNP4, and CNP5) were evaluated. Methods: Physicochemical properties of the five commercial nurungji products were evaluated with AOAC method. The antioxidant activities were assessed using the 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis-(3-ethyl-benozothia zoline-6-sulfonic acid)(ABTS), ferric reducing antioxidant power (FRAP), and reducing power assays. Results: Water content was the highest in CNP3, followed by CNP1, CNP2, CNP5, and CNP4. Crude ash content of all nurungji was less than 1%. In Hunter color parameter, the significantly highest a value (redness) and b value (yellowness) were measured in the CNP4 product, meanwhile the lowest in CNP3 (p<0.05). The nurungji products of CNP4 and CNP5 had the significantly higher content in total polyphenols and total flavonoids, compared to those of other products. CNP3 and CNP2 had the lowest in total polyphenols and total flavonoids, respectively. CNP4 and CNP5 products showed the significantly higher values in antioxidant activities, whereas CNP3 had the lowest activity. Conclusion: The high value of antioxidant activities in CNP4 and CNP5 might have been affected primarily by the total polyphenols with increasing browning color during the heat treatment.

• 한국식품저장유통학회지
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• 제12권6호
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• pp.608-612
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• 2005

친환경적이면서 신속한 비파괴 분석방법인 FT-NIR를 이용하여 백미의 총식이섬유(TDF)함량 예측모델을 개발하였다. 백미는 국내산으로 전남지방에서 재배된 47개 품종과, 시중 유통 중인 13개 브랜드 미에 대해서 AOAC 방법에 준한 효소법에 의해 TDF 함량을 분석하였다. 습식 분석된 TDF함량의 범위는 $1.17-1.92\%$ 이었다. FT-NIR로 측정된 스펙트럼의 검량식은 빛의 산란 효과를 최소화하기 위해 수학적 처리를 하였고, 몇 개의 특정 파장이 아닌 전 파장 영역(1,000-2,500 nm)에 대해서 PLS법으로 작성하였다. 얻어진 검량식의 정확도는 상관계수(r), SEE 및 SEP로 확인하였다. 백미 중 총 식이섬유 함량에 대한 회귀분석을 행한 결과, 검량식의 r은 0.9705, SEE는 0.0464, 검증식의 bias는 -0.0006, SEP가0.0604로 측정 정확도가 우수하여 실제 적용이 가능함을 보여주었다.

• 한국지역사회생활과학회지
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• 제15권3호
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• pp.107-112
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• 2004

Many studies have showen that Letinus edodes have a reducing effects on blood pressure and lipid levels in animals with high blood pressure and hyperlipidemia. But the only cap has been on the market as goods and the stipe has been wasted. The price is very variable and is based on harvest time and the part of the plant currenty, there is not much information about the nutritional composition and bio-fuctional effects of Letinus edodes based on harvest time and part. Some farmers have been selling the powder seasoning by drying and pulverizing Letinus edodes including stipe to develop value added, late harvested Letinus edodes and its stipe these days. This study was conducted to investigate and compare the nutritional composition of Letinus edodes harvested at different times (early: E, late: L) and separated by part (cap: C, stipe: S). The 4 kinds of materials were named as early harvested cap (EC) and stipe (ES), and late harvested cap (LC) and stipe (LS) samples were obtained from Mungyeong City Agricultural Technology & Extension Center. The composition analysis of the nutrients in the 4 materials was conducted by using the AOAC method. The proximate components (moisture, protein, fat, fiber, ash, and carbohydrates), minerals and vitamin content were measured. Nutritional composition of Lentinus edodes did not show any significant difference between early and late harvested mushrooms. Nutritional compositions were different according to part. The results demonstrate that the late harvested stipe can also be used as a quality food material.

• Journal of Nutrition and Health
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• 제29권10호
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• pp.1142-1149
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• 1996

This study was conducted to determine changes in th contents and composition of dietary fiber during the growth of soybean sprout. Soybean was soaked in water at $25^{\circ}C$ for 2hrs and cultivated at 2$0^{\circ}C$ for 7 days under dark condition. The soybean sprouts were divided into cotyledon and axis and sampled every 24hrs. The analysis methodlogies used were Van Soest's NDF, AOAC's ADF and lignin and Prosky's IDF, SDF, TDF. The weight of 100 sprouts increased gradually from 20.26g to 90.12g during the growth periods. The weight increased to 344.9% of the original weight. The germination rate was 100% after soaking at $25^{\circ}C$ for 2hrs. Root length increased gradualy from 0.6cm at 1st day to 17.2cm at 7th day. The crude ash and crude fat contents showed no significant change in the cotyledon and axis. The crude protein contents increased in the cotyledon and axis, whereas the total carbohydrate content didn't have general tendency. The insoluble dietary fiber(IDF), soluble dietary fiber(SDF) and total dietary fiber(TDF) contents of cotyledon were no significantly different from 20.01%, 1.45%, 21.46% at 1st day to 22.75%, 2.07%, 24.82% at 7th day on dry basis. In axis those contents increased from 23.19%, 1.97%, 25.16% at 1st day to 32.78%, 3.02%, 35.80% at 7th day, respectively. The neutral detergent fiber(NDF) contents of cotyledon and axis increased from 4.35% to 6.39% and from 6.44% to 26.60% respectively on dry basis. The acid detergent fiber (ADF) contents of cotyledon and axis increased from 2.84% to 4.91% and from 2.5% to 4.7%, but there were no significantly different in the hemicellulose and lignin contents on dry basis. The hemicellulose and lignin contents of axis increased with culture periods from 1.70% to 4.41% and from 0.20% to 2.11%, respectively. The cellulose contents increased from 4.54% to 20.35% on dry basis.