Tạp chí Kiểm nghiệm và An toàn thực phẩm

Machine learning based on UV-Vis full spectra for the simultaneous determination of curcumin, demethoxycurcumin, bisdemethoxycurcumin in Curcuma longa L

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 11:36:27 +0700

This study has developed a rapid and simple method based on the UV-Vis full spectra coupled with machine learning for the quantitative prediction of curcumin, demethoxycurcumin and bisdemethoxycurcumin in turmeric rhizomes. The UV-Vis spectral data and HPLC quantification results of the individual components from 55 turmeric rhizome samples were utilized for model development and training. Analogous data matrices from an independent set of 24 samples were used for external validation of the developed models. Four machine learning models were investigated, comprising two linear multivariate regression algorithms: principal component regression (PCR) and partial least squares regression (PLSR), two non-linear multivariate regression algorithms: artificial neural network (ANN) and random forest (RF). The results demonstrated that the linear multivariate regression models exhibited superior analytical performance. Specifically, PCR yielded a coefficient of determination (R²) values from 0.957 to 0.982 with root mean square error (RMSE) values from 3.086 to 1.295, while PLSR achieved R² values from 0.956 to 0.979 and RMSE values from 3.116 to 1.139. However, when comparing the HPLC-quantified contents with the values predicted by the two models, some samples still exhibited relative errors exceeding 20%. This study confirms the feasibility of rapidly and simultaneously predicting the contents of curcumin, demethoxycurcumin and bisdemethoxycurcumin in turmeric rhizomes using UV-Vis spectral data coupled with either PLSR or PCR models, offering an efficient alternative to conventional methods.

Simultaneous determination of some heterocyclic amines (HCAs) in processed foods by liquid chromatography tandem mass spectrometry (LC-MS/MS)

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 11:44:01 +0700

Heterocyclic amines (HCAs) are a group of more than 25 chemical compounds containing at least one heterocyclic ring, often produced during the processing of foods such as meat and fish at high temperatures. HCAs have been shown to be carcinogenic and mutagenic. The International Agency for Research on Cancer (IARC) has classified IQ as group 2A and 9 substances including MeIQ, MeIQx, PhIP, AαC, MeAαC, Trp-P- 1, Trp-P-2, Glu-P-1, Glu-P-2 as group 2B, the group that can cause cancer in humans. Human health is seriously harmed if food contaminated with HCAs is regularly consumed. Therefore, it is necessary to develop a method to simultaneously analyze HCAs in food to assess the risk of processed foods in Vietnam. In this study, 10 HCAs in the IARC list were studied and identified by liquid chromatography-mass spectrometry (LC-MS/MS) using a C18 chromatographic column, positive ion electrospray ionization source ESI (+), multiple reaction ion monitoring (MRM) mode. The results showed that the method had good specificity, the standard curve was built in the concentration range of 0.05 - 10 µg/kg, the detection limit was from 0.015 - 0.15 µg/kg, the quantification limit was from 0.05 - 0.5 µg/kg; the precision and accuracy met the requirements according to AOAC. The method was used to analyze the HCAs content in 23 processed food samples in Hanoi. The results showed that 22/23 samples detected HCAs, the sample with the highest content was up to 17.9 µg/kg.

Development and validation of a qPCR method for quantification of Spodoptera exigua nucleopolyhedrovirus in plant protection products

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 11:48:41 +0700

Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) is an important biological control agent widely used as an eco-friendly alternative to chemical pesticides for managing Spodoptera exigua. The efficacy of SeMNPV-based plant protection products strongly depends on the concentration of viral occlusion bodies (OBs); however, conventional quantification methods based on hemocytometer counting are labor-intensive, time-consuming, and subject to operator bias. Therefore, this study aimed to develop and validate a real-time PCR (qPCR) method for the quantification of SeMNPV in plant protection products. In this study, a qPCRbased method for the quantification of SeMNPV was developed by targeting amplification of the dnapol gene, which represents a highly conserved and species-specific genetic marker for this virus. Viral identity was confirmed by dnapol gene sequencing, and hemocytometer-based quantification of viral OBs was employed to determine reference input values for qPCR validation. Method validation was conducted in accordance with ISO 22118:2011 guidelines, evaluating analytical sensitivity, specificity, accuracy, linearity, repeatability, and reproducibility. The assay demonstrated high sensitivity, with both the limit of detection and the limit of quantification established at 10² OBs/mL. Specificity, accuracy, and sensitivity reached 100%, with no crossreactivity observed against non-target baculoviruses. A robust standard curve based on the linear relationship between Ct values and OB concentration showed excellent linearity (R² = 0.994), a slope of -3.151, and an amplification efficiency of 107.6%. Repeatability and reproducibility met acceptance criteria, indicating good precision and method stability. Overall, this study presents the first validated qPCR method for SeMNPV quantification, validated against occlusion body counts, providing a sensitive, specific, and biologically relevant tool for quality control and regulatory assessment of SeMNPV-based biopesticides.

Determination of total dietary fiber, soluble dietary fiber, and insoluble dietary fiber in foods using an enzymatic-gravimetric-liquid chromatographic method

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 11:52:41 +0700

Dietary fiber has been widely recognized for its beneficial effects on human health. Consequently, fiber is increasingly incorporated into dietary supplements and functional foods to enhance daily fiber intake. However, quality control of these products remains challenging due to the structural diversity of dietary fiber and the need for different analytical approaches for each fiber type. This study aimed to determine soluble dietary fiber (SDF), insoluble dietary fiber (IDF), and total dietary fiber (TDF) in food matrices using a combined enzymatic-gravimetricliquid chromatographic method. The method enables the simultaneous determination of TDF, SDF, and IDF in a single analysis and is particularly suitable for complex food samples with unknown fiber composition. Starch was hydrolyzed using pancreatic α-amylase and amyloglucosidase at 37℃ for 4 h, while proteins were digested with protease. IDF was quantified by gravimetric analysis, whereas SDF was determined by liquid chromatography with a refractive index detector. The method was validated in accordance with AOAC guidelines, demonstrating satisfactory specificity, linearity, repeatability (RSD 3.1 - 4.4%), reproducibility (RSD 4.3 - 7.1%), and recovery (92.1 - 105.8%). The validated method was applied to the analysis of 50 randomly collected commercial food samples. Natural food products such as vegetables, fruits, and cereals exhibited high IDF contents (11.3 - 16.7 g/100g), reflecting their characteristic cellulose- and lignin-rich structures. In cereal products, IDF ranged from 5.8 to 9.9 g/100g. In contrast, functional foods and dietary supplements showed significantly lower IDF levels (0.6 - 3.4 g/100g) and predominantly contained soluble dietary fiber, with SDF ranging from 2.1 to 11.8 g/100g.

Preliminary study on distinguishing commercial orange juices based on chemical composition analysis at the laboratory scale

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 16:40:19 +0700

Orange juice is among the most consumed fruit juices worldwide, valued for its nutritional and sensory qualities. However, due to its high economic value, orange juice is also one of the most vulnerable commodities to adulteration, particularly through dilution or substitution with cheaper ingredients. This study aimed to differentiate between natural and commercial orange juice and to evaluate the ability to detect adulteration by dilution with sucrose and citric acid solutions using multivariate statistical approaches. A total of 50 samples, including fresh-squeezed orange juice, commercial juices, and artificially adulterated juices at different levels (10%, 20%, 30%, 50%, and 90%), were analyzed for organic acid composition (oxalic acid, malic acid, ascorbic acid, citric acid, and furmaric acid), flavonoids (hesperidin, narirutin) analyzed by HPLC-PDA and sugars (fructose, glucose, and sucrose) analyzed by HPLC-RID. Principal Component Analysis (PCA) was first applied to reduce data dimensionality and to identify major compounds contributing to the variation among samples. Subsequently, Discriminant Analysis based on PCA scores (PCA-DA) was used for classification and model validation. The results showed that PCA successfully separated natural juices from commercial ones, with citric acid, glucose, fructose, hesperidin, and narirutin being the main discriminant markers. For the adulterated juice experiment, PCA-DA achieved clear separation of groups, with 100% correct classification when three principal components were included in the model. These findings confirm that combining chemical profiling with PCA and PCA-DA is a reliable and efficient approach for authenticity testing of orange juice. The method provides a promising analytical tool for quality control laboratories and regulatory agencies to combat economically motivated adulteration in fruit juices.

Determination of the glycaemic index (GI) of corn noodles

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 16:44:26 +0700

The study was conducted to determine the glycaemic index (GI) of corn noodles. The study was conducted on 14 healthy adult volunteers, applying the method according to TCVN 10036: 2013 (ISO 26642: 2010). Data were processed using Microsoft Excel software and the results were evaluated according to the prescribed standards. The results showed that the research product had a glycaemic index (GI) of 58.0. Corn noodles are classified as foods with an average glycaemic index. The product has the potential to be used as a supplement in daily meals for people who need to control blood sugar levels (pre-diabetics, obese people).

Extraction of astaxanthin from Haematococcus pluvialis microalgae using a biphasic solvent system

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 16:47:47 +0700

This study focused on the effect of a two-solvent immiscible system consisting of 0.2M H2SO4 solution and ethyl acetate - hexane mixture for rapid extraction and recovery of astaxanthin and its derivatives from Haematococcus pluvialis (H. pluvialis). The effect of changing the composition of solvent in the two-phase liquid system on the ability to extract astaxanthin was evaluated and then, the ratio of the organic solvent mixture was optimized. The results under the survey conditions showed that the maximum extraction efficiency reached 95.02 ± 1.88% with the organic solvent volume/microalgae mass ratio was 12 mL/g when hexane/ethyl acetate ratio was 1/1, showcase significantly higher than the single solvent extraction efficiency. The results of the optimal function calculation using the centered combination method gave an expected organic solvent volume/microalgae mass ratio was 9.563 mL/g with the hexane ratio in the organic solvent was 61.31%, the expected efficiency achieved was 83.26%. In addition, the study also showed that the concentration of H2SO4 only affects the process of cell wall disruption and have none affecting the dissolution process. Plus, the dissolution reaction of astaxanthin from H. pluvialis microalgae is a first-order chemical reaction.

Method development for simultaneous analytical method for ten ginsenosides in soft-gel dietary supplements containing Panax spp. by LC-MS/MS

Tạp chí Kiểm nghiệm và An toàn thực phẩm — Sun, 29 Mar 2026 16:50:32 +0700

A liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous quantification of ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, notoginsenoside R1 and majonoside R2 in dietary supplement products containing ginseng. A Waters ACQUITY UPLC BEH C18 column (100 mm × 2.1 mm, 1.7 μm) was employed as the separation column and maintained at 40℃ during analysis. The mobile phase consisted of 0.1% formic acid and acetonitrile, delivered under an optimized gradient program. Detection was by tandem mass spectrometry using electrospray ionization in the positive ion mode and multiple reaction monitoring (MRM). The sample were defatted with hexane before extraction with 50% methanol at 75℃ for 30 min by sonication. The method was validated following AOAC guidelines and Commission Decision 2002/657/EC. The results demonstrated good specificity, linearity over the range of 100 - 2000 ng/mL, the detection limit and quantitative limit of the method are 1.43 - 1.85 and 4.18 - 5.41 μg/g. The validated method was successfully applied to determine ginsenoside content in ten different ginseng-based dietary supplements available on the Vietnamese market.