Hee-Jae Suh

Under-reporting of Energy Intake from 24-hour Dietary Recalls in the Korean National Health and Nutrition Examination Survey

Objectives Chronic degenerative diseases are closely related to daily eating habits, nutritional status, and, in particular, energy intake. In clarifying these relationships it is very important for dietary surveys to report accurate information about energy intake. This study attempted to identify the prevalence of the under-reporting of energy intake and its related characteristics based on the Korean National Health and Nutrition Examination Survey conducted in the years 2007–2009. Methods The present study analyzed dietary intake data from 15,133 adults aged ≥19 years using 24-hour dietary recalls. Basal metabolic rates were calculated from the age- and gender-specific equations of Schofield and under-reporting was defined as an energy intake <0.9, represented by the ratio of energy intake to estimated basal metabolic rate. Results Under-reporters (URs) accounted for 14.4% of men and 23.0% of women and the under-reporting rate was higher in the age group 30–49 years for both men and women. The results from an analysis of the age-specific socioeconomic characteristics of participants classified as URs showed that under-reporting was high in women living alone and in women with only elementary school education or no education. The results from an analysis of the health-specific characteristics of URs showed that a large proportion of URs had poor self-rated health or were obese, or both, compared with non-URs. The proportion of participants who consumed less than the estimated average requirements for nutrients was significantly higher in URs compared with non-URs. Conclusion The under-reporting of energy intake was associated with age, gender, education level, income level, household status (single-person or multi-person), self-rated health, physical activity, and obesity.

Simultaneous determination of sodium iron chlorophyllin and sodium copper chlorophyllin in food using high-performance liquid chromatography and ultra-performance liquid chromatography–mass spectrometry

A simultaneous method for analyzing sodium iron chlorophyllin (SIC) and sodium copper chlorophyllin (SCC) using high-performance liquid chromatography was developed. This method employed an Inertsil ODS-2 column and diode array detection at 395 nm, using methanol-water (97:3 and 80:20, v/v) containing 1% acetic acid as the mobile phase. Liquid chromatography-tandem mass spectrometry was used to identify the main components of SIC and SCC as Fe-isochlorine e4 and Cu-isochlorine e4, respectively. The limits of detection and quantitation of SIC were 1.2 and 4.1 mg/kg, respectively, while those of SCC were 1.4 and 4.8 mg/kg, respectively. For intraday and interday tests, the SIC recoveries from candy ranged from 81% to 101%, while SCC recoveries ranged from 100% to 109%. The developed method can be applied to the rapid determination of SIC and SCC in candy.

Establishment and Validation of an Optimized Analytical Method for Sodium Copper Chlorophyllin in Food Using HPLC and LC/MS

본 연구는 우리나라에서 식품 착색료로 이용되고 있는 동클로로필린 나트륨의 최적 분석법을 개발하기 위하여 수행되었다. 제외국의 동 클로로필린 나트륨 분석법을 검토하여 식품 중 동 클로로필린 나트륨 추출방법, HPLC-PDA를 이용한 기기분석 조건, LC/MS를 이용한 동 클로로필린 나트륨 유도체 분석을 통하여 동 클로로필린 나트륨 최적 분석법을 확립하고 분석법의 타당성을 검토한 결과는 다음과 같다. 동 클로로필린 나트륨은 Inertsil ODS-2 column과 1% 초산을 함유한 메탄올-물(97:3, v/v)을 이동상으로 HPLCPDA를 이용하여 405 nm에서 분석할 때 우수한 분리능과 머무름 시간, 재현성이 확보된 피크를 얻을 수 있었다. LC/MS를 이용하여 동 클로로필린 나트륨을 이루는 피크를 분석한 결과 동 이소클로린 e4가 주 피크의 구성성분임을 확인할 수 있었다. 확립된 분석법의 타당성을 검증하기 위해 직선성, 검출한계, 정량한계, 정밀도, 정확도, 회수율 및 실험실 간 교차검증을 실시한 결과, 직선성은 0~700 mg/kg범위에서 R2=0.9999로 나타났고, 검출한계와 정량한계는 각각 0.1 mg/kg과 0.4 mg/kg으로 나타났다. 정밀도는 일간분석과 일내분석이 각각 1.6~8.1과 0.5~2.6으로 나타났고, 정확도는 일간분석과 일내분석이 각각 89.2~102.2%와 90.4~100.5%로 나타나 국제표준화기구의 기준에 근접하였다. 또한, 본 연구에서 개발한 전처리법으로 식품 중 함유된 동 클로로필린 나트륨 회수율 분석을 실시한 결과 수용성식품(캔디류)의 경우는 104~109%, 유지류(샐러드드레싱)의 경우 농도별로 104~119%로 나타나 식품 매트릭스별 회수율 평균이 95% 이상으로 매우 우수하였다. 실험실 간 교차검증을 실시한 결과 세 기관의 R2값은 모두 0.998 이상으로 좋았으며, 각 실험실 회수율에 대한 RSD 값이 농도별로 6~16%로 나타나 향후 공인 분석 방법으로 활용 가능하다는 것을 확인할 수 있었다.

An Improved Analytical Method for the Determination of Brown FK in Food using HPLC

In this study, an improved analytical method for the detection of the colorant Brown FK in foods using high-performance liquid chromatography was developed. The method, which employed an RC-C18 column and diode array detection at 254 nm with sodium acetate solution and methanol as mobile phases, exhibited good linearity (R2 = 1.0), and its limits of detection and quantification were determined to be 0.06 and 0.19 μg/mL, respectively. The precision was found to be 0-1.2% and the accuracy was between 86.5% and 94.8%. Liquid chromatography-tandem mass spectrometry was also performed to identify Brown FK in peaks. The pretreatment method was optimized for three different food sample groups, i.e., seafood, noodles and other, affording recoveries of 86.5-92.8%, 90.8-94.8% and 90.0-92.3%, respectively. In addition, inter-laboratory testing was also conducted to check the precision.