Detection of melamine in milk powders using near-infrared hyperspectral imaging combined with regression coefficient of partial least square regression model

Lim, Jongguk,Kim, Giyoung,Mo, Changyeun,Kim, Moon S.,Chao, Kuanglin,Qin, Jianwei,Fu, Xiaping,Baek, Insuck,Cho, Byoung-Kwan Elsevier 2016 Talanta Vol.151 No.-

<P><B>Abstract</B></P> <P>Illegal use of nitrogen-rich melamine (C<SUB>3</SUB>H<SUB>6</SUB>N<SUB>6</SUB>) to boost perceived protein content of food products such as milk, infant formula, frozen yogurt, pet food, biscuits, and coffee drinks has caused serious food safety problems. Conventional methods to detect melamine in foods, such as Enzyme-linked immunosorbent assay (ELISA), High-performance liquid chromatography (HPLC), and Gas chromatography–mass spectrometry (GC–MS), are sensitive but they are time-consuming, expensive, and labor-intensive. In this research, near-infrared (NIR) hyperspectral imaging technique combined with regression coefficient of partial least squares regression (PLSR) model was used to detect melamine particles in milk powders easily and quickly. NIR hyperspectral reflectance imaging data in the spectral range of 990–1700nm were acquired from melamine-milk powder mixture samples prepared at various concentrations ranging from 0.02% to 1%. PLSR models were developed to correlate the spectral data (independent variables) with melamine concentration (dependent variables) in melamine-milk powder mixture samples. PLSR models applying various pretreatment methods were used to reconstruct the two-dimensional PLS images. PLS images were converted to the binary images to detect the suspected melamine pixels in milk powder. As the melamine concentration was increased, the numbers of suspected melamine pixels of binary images were also increased. These results suggested that NIR hyperspectral imaging technique and the PLSR model can be regarded as an effective tool to detect melamine particles in milk powders.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Melamine particles contained in milk powder were detected by NIR hyperspectral imaging. </LI> <LI> Regression coefficient values were used to reconstruct the PLS images. </LI> <LI> PLS images were used to discriminate the melamine pixels from milk powder pixels. </LI> <LI> Melamine particles at 200ppm in milk powder were confirmed without pretreatment. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A rapid and reliable method for discriminating rice products from different regions using MCX-based solid-phase extraction and DI-MS/MS-based metabolomics approach

Lim, Dong Kyu,Mo, Changyeun,Long, Nguyen Phuoc,Lim, Jongguk,Kwon, Sung Won Elsevier 2017 Journal of chromatography. B, Analytical technolog Vol.1061 No.-

<P><B>Abstract</B></P> <P>The expansion of the global rice marketplace ultimately raises concerns about authenticity control. Several analytical methods for differentiating the geographical origin of rice have been developed, yet a high-throughput method is still in demand. In this study, we developed a rapid approach using direct infusion-mass spectrometry (DI-MS) to distinguish rice products from different countries. Specifically, the elimination of the matrix effect by a polytetrafluoroethylene (PTFE) filter, a mixed-mode cation exchange (MCX) solid-phase extraction (SPE) with 20% methanol, and an MCX SPE with 100% methanol were measured. Afterward, partial least squares discriminant analysis and random forests were applied to seek the optimal discrimination method. The results revealed that the combination of MCX SPE with 100% methanol and DI-MS in positive ion mode (accuracy=1.000, R<SUP>2</SUP> =0.916, Q<SUP>2</SUP> =0.720, B/W-based <I>p</I>-value=0.015) or the combination of MCX SPE with 20% methanol and targeted DI-MS/MS in positive ion mode (accuracy=1.000, R<SUP>2</SUP> =0.931, Q<SUP>2</SUP> =0.849, B/W-based <I>p</I>-value=0.002) showed the excellent discriminatory ability. Furthermore, differentially expressed metabolites including sodiated lysophosphatidylcholine, lysophosphatidylcholine, lysophosphatidylethanolamines and lysophosphatidylglycerol classes were found. In conclusion, our study provides a rapid and reliable platform for geographical discrimination of white rice and will contribute to the authenticity control of rice products.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Non-destructive profiling of volatile organic compounds using HS-SPME/GC-MS and its application for the geographical discrimination of white rice

Lim, Dong Kyu,Mo, Changyeun,Lee, Dong-Kyu,Long, Nguyen Phuoc,Lim, Jongguk,Kwon, Sung Won The Journal of Food and Drug Analysis (JFDA), Food 2018 JOURNAL OF FOOD AND DRUG ANALYSIS Vol.26 No.1

<P>The authenticity determination of white rice is crucial to prevent deceptive origin labeling and dishonest trading. However, a non-destructive and comprehensive method for rapidly discriminating the geographical origins of white rice between countries is still lacking. In the current study, we developed a volatile organic compound based geographical discrimination method using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME/GC-MS) to discriminate rice samples from Korea and China. A partial least squares discriminant analysis (PLS-DA) model exhibited a good classification of white rice between Korea and China (accuracy = 0.958, goodness of fit = 0.937, goodness of prediction = 0.831, and permutation test p-value = 0.043). Combining the PLS-DA based feature selection with the differentially expressed features from the unpaired t-test and significance analysis of microarrays, 12 discriminatory biomarkers were found. Among them, hexanal and 1-hexanol have been previously known to be associated with the cultivation environment and storage conditions. Other hydrocarbon biomarkers are novel, and their impact on rice production and storage remains to be elucidated. In conclusion, our findings highlight the ability to rapidly discriminate white rice from Korea and China. The developed method maybe useful for the authenticity and quality control of white rice. Copyright (C) 2017, Food and Drug Administration, Taiwan. Published by Elsevier Taiwan LLC.</P>

The integration of multi-platform MS-based metabolomics and multivariate analysis for the geographical origin discrimination of Oryza sativa L.

Lim, Dong Kyu,Mo, Changyeun,Lee, Jeong Hee,Long, Nguyen Phuoc,Dong, Ziyuan,Li, Jing,Lim, Jongguk,Kwon, Sung Won Elsevier Science B.V., Amsterdam 2018 JOURNAL OF FOOD AND DRUG ANALYSIS Vol.26 No.2

Development and Performance Evaluation of Falling-type Dried-Persimmon Weight Sorting System Utilizing Load Cell

Lim, Jongguk,Kim, Giyoung,Mo, Changyeun,Choi, Inchul Korean Society for Agricultural Machinery 2015 바이오시스템공학 Vol.40 No.4

Purpose: A falling-type weight sorter equipped with a load cell was developed to sort lightweight dried persimmons. The performance of the sorter was also evaluated. Methods: The electronic weight sorter for dried persimmon comprises a feeder part, a weight-measurement part, an indicator part, a carrier cup, a discharging part, and a driving part. The weight setting and zero-point adjustment are performed digitally for the convenience of users. For the experimental trials, 228 rubber-clay specimens (representative of dried persimmons) in the weight range of 24.73~99.56 g were manufactured for use in experiments to evaluate the performance of the sorter. Results: The average error of the weight measurements from three experimental trials was 1.655%, with a bias of -0.492 g, a root-mean-square error (RMSE) of ${\pm}0.808g$, and a coefficient of determination ($R^2$ ) of 0.997. Conclusions: The load-cell-based electronic dried-persimmon weight sorter developed in this study facilitates effective, precise, and convenient sorting of dried persimmons.

Optimized Mass Spectrometry-Based Metabolite Extraction and Analysis for the Geographical Discrimination of White Rice (Oryza sativa L.): A Method Comparison Study

Lim, Dong Kyu,Long, Nguyen Phuoc,Mo, Changyeun,Dong, Ziyuan,Lim, Jongguk,Kwon, Sung Won Oxford University Press 2018 Journal of AOAC International Vol.101 No.2

<B>Abstract</B><P>In this study, we examined the effects of different extraction methods for the GC-MS- and LC-MS-based metabolite profiling of white rice (Oryza sativa L.). In addition, the metabolite divergence of white rice cultivated in either Korea or China was also evaluated. The discrimination analysis of each extraction method for white rice from Korea and China and the corresponding discriminatory markers were estimated by unpaired t-test, principal component analysis, k-means cluster analysis, partial least-squares discriminant analysis (PLS-DA), and random forest (RF). According to the prediction parameters obtained from PLS-DA and RF classifiers as well as features that could be identified, the extraction method using 75% isopropanol heated at 100°C coupled with LC-MS analysis was confirmed to be superior to the other extraction methods. Noticeably, lysophospholipid concentrations were significantly different in white rice between Korea and China, and they are novel markers for geographical discrimination. In conclusion, our study suggests an optimized extraction and analysis method as well as novel markers for the geographical discrimination of white rice.</P>

Non-destructive and Rapid Prediction of Moisture Content in Red Pepper (Capsicum annuum L.) Powder Using Near-infrared Spectroscopy and a Partial Least Squares Regression Model

Lim, Jongguk,Mo, Changyeun,Kim, Giyoung,Kang, Sukwon,Lee, Kangjin,Kim, Moon S.,Moon, Jihea Korean Society for Agricultural Machinery 2014 바이오시스템공학 Vol.39 No.3

Purpose: The aim of this study was to develop a technique for the non-destructive and rapid prediction of the moisture content in red pepper powder using near-infrared (NIR) spectroscopy and a partial least squares regression (PLSR) model. Methods: Three red pepper powder products were separated into three groups based on their particle sizes using a standard sieve. Each product was prepared, and the expected moisture content range was divided into six or seven levels from 3 to 21% wb with 3% wb intervals. The NIR reflectance spectra acquired in the wavelength range from 1,100 to 2,300 nm were used for the development of prediction models of the moisture content in red pepper powder. Results: The values of $R{_V}{^2}$, SEP, and RPD for the best PLSR model to predict the moisture content in red pepper powders of varying particle sizes below 1.4 mm were 0.990, ${\pm}0.487%$ wb, and 10.00, respectively. Conclusions: These results demonstrated that NIR spectroscopy and a PLSR model could be useful techniques for measuring rapidly and non-destructively the moisture content in red pepper powder.

Original Article Journal of Biosystems Engineering : Development and Performance Evaluation of Falling-type Dried-Persimmon Weight Sorting System Utilizing Load Cell

( Jongguk Lim ),( Giyoung Kim ),( Changyeun Mo ),( Inchul Choi ) 한국농업기계학회 2015 바이오시스템공학 Vol.40 No.4

Purpose: A falling-type weight sorter equipped with a load cell was developed to sort lightweight dried persimmons. The performance of the sorter was also evaluated. Methods: The electronic weight sorter for dried persimmon comprises a feeder part, a weight-measurement part, an indicator part, a carrier cup, a discharging part, and a driving part. The weight setting and zero-point adjustment are performed digitally for the convenience of users. For the experimental trials, 228 rubber-clay specimens (representative of dried persimmons) in the weight range of 24.73~99.56 g were manufactured for use in experiments to evaluate the performance of the sorter. Results: The average error of the weight measurements from three experimental trials was 1.655%, with a bias of -0.492 g, a root-mean-square error (RMSE) of ±0.808 g, and a coefficient of determination (R(2)) of 0.997. Conclusions: The load-cell-based electronic dried-persimmon weight sorter developed in this study facilitates effective, precise, and convenient sorting of dried persimmons.

Development of Models for the Prediction of Domestic Red Pepper (Capsicum annuum L.) Powder Capsaicinoid Content using Visible and Near-infrared Spectroscopy

Lim, Jongguk,Mo, Changyeun,Kim, Giyoung,Kim, Moon S.,Lee, Hoyoung Korean Society for Agricultural Machinery 2015 바이오시스템공학 Vol.40 No.1

Purpose: The purpose of this study was to non-destructively and quickly predict the capsaicinoid content of domestic red pepper powders from various areas of Korea using a pungency measurement system in combination with visible and near-infrared (VNIR) spectroscopic techniques. Methods: The reflectance spectra of 149 red pepper powder samples from 14 areas of Korea were obtained in the wavelength range of 450-950 nm and partial least squares regression (PLSR) models for the prediction of capsaicinoid content were developed using area models. Results: The determination coefficient of validation (RV2), standard error of prediction (SEP), and residual prediction deviation (RPD) for the capsaicinoid content prediction model for the Namyoungyang area were 0.985, ${\pm}2.17mg/100g$, and 7.94, respectively. Conclusions: These results show the possibility of VNIR spectroscopy combined with PLSR models in the non-destructive and facile prediction of capsaicinoid content of red pepper powders from Korea.

미세진동 스크린 방식의 동애등에 유충 탈수 장치 개발

임종국 ( Jongguk Lim ),김밝금 ( Balgeum Kim ),이아영 ( Ahyeong Lee ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

곤충을 이용한 고단백 사료 제품은 동물 사료의 대체제로서 주목받고 있으며 자원 재생을 위한 새로운 대안으로 떠오르고 있다. 곤충 단백질 시장은 ‘19년에는 1억 4,400만 달러에서 ’25년에는 13억 3,600만 달러까지 증가할 것으로 전망한다. 동애등에 유충은 파리목 동애등에과에 속하는 동애등에 곤충의 애벌레로 남은 음식물을 10여 일 동안에 소화하면서 약 20mm 정도의 크기까지 성장한다. 동애등에 유충 5,000마리는 약 10kg의 남은 음식물을 80%까지 분해할 수 있어서 환경 정화용으로 활용 가치가 아주 높은 익충이다. 동애등에 유충이 배출하는 분변토는 함수율이 높아서 기존 메시 구조의 스크린 선별기로는 완벽한 유충 분리가 어려워 대량생산에 어려움을 겪고 있다. 따라서 본 연구에서는 동애등에 유충과 분변토의 혼합물 침전수에서 분변토를 분리하고 유충 표면에 남아있는 물기를 제거하기 위해서 미세진동 스크린 방식이 적용된 동애등에 유충 탈수 장치를 개발하였다. 동애등에 유충 탈수 장치는 동애등에 유충과 분변토가 혼합된 침전수를 공급하기 위한 직경φ50mm의 투입 배관, 미세진동을 발생시키기 위한 출력 0.4kW의 진동모터, 와이어의 두께가 0.5mm이고 메시(mesh)가 #30인 폭과 길이가 600mm × 1,600mm으로 제작된 스크린, 본체의 진동 발생을 최소화하기 위한 4개의 방진 스프링, 탈수된 물이 배출되는 배수관, 제어 장치 등으로 구성되어 있다. 작동 방식은 상부로 투입되는 동애등에 유충과 분변토가 혼합된 침전수가 상부 투입 배관을 통해 미세진동이 발생하는 스크린에 투입된다. 스크린 상부에 투입된 침전수는 스크린 하부로 대부분 떨어진다. 진동모터에 의해 발생한 미세진동은 동애등에 유충을 스크린의 앞부분에서 뒷부분으로 진동과 함께 1,600mm의 길이 방향으로 전진시키면서 표면의 물기를 제거한다. 미세진동을 이용한 탈수 방식은 기존 원심 분리식이나 진동 방식과 비교할 때 동애등에 유충에 대한 손상을 최소화할 수 있어 대량으로 유충을 생산하는 공정에 투입되면 생산성을 향상할 수 있을 것으로 기대된다.