Microbiological quality of edible vegetable oils produced and marketed in Gondar City, Northwest Ethiopia.

Edible oils are imported and produced in Ethiopia, notably in Gondar, and their production has expanded considerably in recent years. The expansion of locally produced edible vegetable oils with severe quality control, substandard edible oil production, and quality deterioration may contribute to the contamination of microbes, which may cause public health problems. This study determines the microbiological quality of edible vegetable oils being produced and marketed in Gondar City, Northwest Ethiopia, in 2021. A laboratory-based cross-sectional study design was conducted from May to July 2021 in Gondar City. A simple random sampling technique was used to collect 17 edible vegetable oil samples. Aseptically collected samples were analyzed in the microbiology lab room. The microbiological quality of vegetable oil was assessed using standard microbiological procedures and techniques. The collected data were entered into a Microsoft Excel 2016 spreadsheet and Stata Version 14. A non-parametric Kruskal-Wallis test was used to assess significant variation. Seventeen edible vegetable oil samples were examined and found to contain a varying number of bacteria, yeast, and molds. Staphylococcus aureus, Klebsiella Pneumoniae, and Pseudomonas aeruginosa were the identified bacteria, whereas Saccharomyces cerevisiae, Aspergillus niger, Aspergillus flavus, and Aspergillus fumigatus were the identified fungi. Total coliform and fecal coliform isolates were also identified in the oil samples. A level of microbial contamination that has public health importance was observed in some of the oil samples analyzed, and the isolated microorganisms indicate unhygienic handling, processing, and storage practices in the oil production and market sites. The introduction of strict rules, regulations, and updated manufacturing technologies and processes to ensure food safety and quality is needed.

Benefits and Harms of Edible Vegetable Oils and Fats Fortified with Vitamins A and D as a Public Health Intervention in the General Population: A Systematic Review of Interventions.

This systematic review aims to assess whether edible vegetable oils and fats fortified with vitamin A and/or D are effective and safe in improving vitamin intake and ameliorating deficiency states in the general population. In November 2022, we systematically searched MEDLINE, Cochrane CENTRAL, Scopus, Global Index Medicus, ClinicalTrials.gov, and WHO ICTRP (International Clinical Trials Registry Platform) for randomized controlled trials (RCT) and non-randomized studies of interventions (NRSI) investigating the fortification of edible vegetable oils and fats with either vitamin A or vitamin D or both as compared to the same vegetable oils and/or fats without vitamin A and D fortification or no interventions, in the general population, without age restriction. We assessed the methodological quality of included RCTs using Cochrane's risk of bias tool 2.0 and of NRSIs using ROBINS-I tool. We performed random-effects meta-analysis and assessed certainty of evidence using GRADE. We included eight studies. Available evidence showed no significant effect of fortification with vitamin A on serum retinol levels (RCTs: MD 0.35 µmol/L, 95% CI -0.43 to 1.12; two trials; 514 participants; low-certainty evidence; CCTs: MD 0.31 µmol/L, 95% CI -0.18 to 0.80; two trials; 205 participants; very low-certainty evidence) and on subclinical vitamin A deficiency. Low-certainty evidence showed no effect of vitamin D fortification on serum 25-hydroxy vitamin D concentration (MD 6.59 nmol/L, 95% CI -6.89 to 20.07; one trial; 62 participants). In conclusion, vitamin A-fortified vegetable oils and fats may result in little to no difference in serum retinol levels in general populations. The dose of vitamin A used in the trials may be safe but may not be sufficient to reduce subclinical vitamin A deficiency. Further, the evidence suggests that vitamin D fortification results in little to no difference in serum 25-hydroxy vitamin D concentration. Several aspects of providing fortified oils and fats to the general population as a public health intervention should be further investigated, including optimal fortification dose, effects on vitamin D deficiency and its clinical symptoms and potential adverse effects.

[Contamination and dietary exposure assessment of 2-chloropropanol esters in vegetable oils available on Zhejiang market during 2016-2020].

OBJECTIVE: To investigate the occurrence data for 2-chloropropanol(2-MCPD) ester in edible vegetable oils purchased in Zhejiang Province during 2016-2020, and to estimate dietary exposures of 2-MCPD ester via vegetable oil. METHODS: A total of 404 samples of edible oils were collected from markets, stores, online shopping in Zhejiang Province, the occurrence of 2-MCPD ester was detected by gas chromatography mass spectrometry from 2016-2020. Data of vegetable oils consumption was obtained from the survey result of urban and rural residents in Zhejiang Province in 2008. The exposure levels of 2-chloropropanol ester was calculated for people aged 4-6, 7-10, 11-17, 18-59 and 60 years old and older from the consumption of vegetable oils. RESULTS: The detection rate of 2-MCPD esters in 404 samples was 82.7%(334/404) with the mean level of 0.32 mg/kg. Among them, the mean content of camellia oil was the highest with 1.23 mg/kg, followed by rice oil(0.69 mg/kg); sunflower oil, olive oil and soybean oil have relatively low average values, respectively with 0.11, 0.12 and 0.13 mg/kg. There are significant differences in 2-MCPD ester content in different types of edible oils of the same brand(P<0.05), the content of 2-MCPD ester in different brands of peanut oil was significant(P<0.05), but in different brands of corn oil was not statistically significant. Among the edible vegetable oil consumers, the average exposure of 2-MCPD esters in different age groups ranged from 0.21 to 0.69 µg/(kg·BW·d). CONCLUSION: 2-MCPD esters pollution is widespread in vegetable oils, the severity of pollution was affected by the type and brand of the edible vegetable oil, and the intake of 2-MCPD esters was relatively high among people with high vegetable oil consumption and the general population of 4-10 years old.

Fluorescence Lifetime of Chlorophyll α in Oxidized Edible Vegetable Oil.

To promote the application of time-resolved fluorescence in oxidation determination of edible vegetable oil, fluorescence lifetime of chlorophyll α in oxidized edible vegetable oils was recorded and analyzed by simulated microenvironment experiments and spectral methods. It was showed that fluorescence lifetime of chlorophyll α decreased with the increase of polarity in the early stage of oxidation, and increased with the increase of viscosity in the later stage of oxidation. Conjugation effect and hydrogen bonding existed in the microenvironment of oxidized edible vegetable oil were considered to be the factors leading to the increase of fluorescence lifetime. The change mechanism of fluorescence lifetime in oxidized edible vegetable oil was supplied, which was considered to be strong support for the application of time-resolved fluorescence.

Exposure assessment of aflatoxins and zearalenone in edible vegetable oils in Shandong, China: health risks posed by mycotoxin immunotoxicity and reproductive toxicity in children.

Human exposure to aflatoxins (AFs) and zearalenone (ZEA) has not been sufficiently investigated. Here, we analyzed the exposure level and health risks posed by AFs (B1, B2, G1, G2) and ZEA through cooking oil consumption in Shandong, China. The individual daily consumption of cooking oil was calculated through 2745 questionnaires during 2017-2019. The average contamination levels of mycotoxins were estimated by examining 60 cooking oil samples. For the peanut oil, AFs ranged from <0.2 to 274 µg/kg, with a positive rate of 66.6% (20/30). Average levels of 36.62 µg/kg AFB1 and 44.43 µg/kg total AFs were found. Over-the-limit level (20 µg/kg) of AFB1 was detected in 8/30 samples. Estimated daily intake (EDI) and margin of exposure (MOE) for age-stratified population groups showed that children are facing highest adverse health risk with AFB1 (MOE 5.88-6.39). The liver cancer incidences attributable to AFB1 exposure are non-negligible as 0.896, 0.825, and 0.767 cases per 100,000 for 6-14 age group, 15-17 age group, and adult labor-intensive workers. Over-the-limit level (60 µg/kg) ZEA contamination was detected in 25/30 corn oil samples with a 50th percentile value of 97.95 µg/kg. Our health risk assessment suggested significant health risks of enterohepatic (inflammation and cancer), reproductive, and endocrine systems posed by AFs and ZEA. However, the health risk of immunotoxicity is unclear because currently animal study data are not available for the immunotoxicity induced after long-term exposure. In general, the health risks posed by mycotoxins are non-negligible and long-term mycotoxin surveillance is necessary.

[Contamination level and population exposure assessment of chloropropanol esters in edible vegetable oil in Shandong Province from 2016 to 2020].

OBJECTIVE: To investigate the contamination of 2-chloropropanol esters and 3-chloropropanol esters in commercial edible vegetable oils in Shandong Province, and to assess the dietary 3-chloropropanol esters exposure and the health risk of intaking 3-chloropropanol esters. METHODS: From 2016 to 2020, 406 individually packaged edible vegetable oils were collected from stores and farmers' markets in 16 prefecture-level cities in Shandong Province. According to the 2016 National Food Contamination and Harmful Factors Risk Monitoring Manual, using gas chromatography-triple quadrupole tandem mass spectrometry detection, isotope internal standard method for quantification, laboratory determination of 2-chloropropanol ester and 3-chloropropanol in vegetable oil ester content. Combined with population weight, oil consumption and monitoring data, the point assessment method was used to evaluate the exposure of residents in Shandong Province to 3-chloropropanol esters. RESULTS: The detection rate of 3-chloropropanol ester was 92.4%(375/406), the concentration range was<limit of detection(LOD)-18.4 mg/kg, the median was 0.470 mg/kg, the average was 0.833 mg/kg, and the maximum value was 18.4 mg/kg in rice oil; the detection rate of 2-chloropropanol ester was 88.7%(360/406), the concentration range was <LOD-8.46 mg/kg, the median value was 0.204 mg/kg, the average value was 0.432 mg/kg, and the maximum value was 8.46 mg/kg in rice oil. The average exposure of each age group was less than the tolerable daily intake, and the high-end exposure of the children(2-6 years old) and adolescents(7-10 years old) group was greater than the tolerable daily intake. CONCLUSION: The contamination of chloropropanol esters of edible vegetable oil in Shandong Province from 2016 to 2020 is widespread, and the highest detection value appears in rice oil. Children(2-6 years old) and adolescents(7-10 years old) in high-risk situations ingest 3-chloropropanol esters present health risks.

Physico-chemical and thermal characteristics of sandy loam soils contaminated by single and mixed pollutants (mineral and vegetable oils).

Samples of contaminated top soil (0-30 cm) and uncontaminated soil (control) from two locations in Precambrian basement complex area were analyzed to assess the effects of single and mixed oil contaminants on the physico-chemical and thermal properties of soils. Pearson's correlation and analysis of variance (ANOVA) were used to study the interrelationships of the studied parameters as well as variation of studied soil characteristics under the different oil contaminants, respectively. Results showed insignificant impact of pollutant(s) on the textural class of contaminated soils. The highest and lowest mean soil resistivity (SR) values were found in petrol-contaminated and mixed surfactants (shampoo + conditioner) -contaminated soils, respectively. The least values of mean specific heat capacity (SHC), heat capacity (HC), and soil water diffusivity (SWD) were found in soils contaminated by mixed surfactants-contaminants. However, mixed mineral oils (petrol + diesel + engine oil) and mixed vegetable oils (palm oil + groundnut oil) had mean SHC values lower than those of control soils at the two sampling locations. The mixed surfactants-polluted soil is characterized by lowest mean bulk density (BD) and highest mean gravimetric water content (GWC) while lowest mean GWC and highest mean SWD characterized engine oil-contaminated soils. The analysis of variance (ANOVA) result revealed significant variation in % sand at 5% level (p < 0.05) for petroleum-derived contaminants but no significant differences in mean values of all analyzed soil properties under vegetable oil contaminants.

Qualitative and Quantitative Analysis of Six Fatty Acid Amides in 11 Edible Vegetable Oils Using Liquid Chromatography-Mass Spectrometry.

Fatty acid amides (FAAs) are endogenous lipid molecules that exhibit various physiological activities. FAAs are usually present at nanomolar levels in biological samples. In this study, a method for the qualitative and quantitative determination of six FAAs (linoleamide, linoleoyl ethanolamide, oleoyl ethanolamide, palmitic amide, oleamide, and octadecanamide) in edible vegetable oils was established. All six FAAs were detected in sesame, peanut, soybean (decolorized and non-decolorized), and blended oils; five in sunflower oil; four in rice oil; three in linseed and olive oils; and two in corn and canola oils. The total contents of FAAs were highest in sesame oil (104.88 ± 3.01 µg/mL), followed by peanut oil (34.96 ± 3.87 µg/mL), soybean oil (16.75 ± 1.27 µg/mL), and blended oil (13.33 ± 0.77 µg/mL), and the contents in the other edible vegetable oils were all <1.03 µg/mL. The concentrations of linoleoyl ethanolamide and oleoyl ethanolamide were highest in non-decolorized soybean oil, while the other four FAAs (linoleamide, palmitic amide, oleamide, and octadecanamide) showed the highest concentrations in sesame oil. The total contents of these FAAs in eight different oils were higher than those in biological fluids and tissue. Our study confirmed that edible vegetable oils are rich in FAAs, and provides reliable data for evaluating the nutritive value of vegetable oils.

Reflectance spectroscopy with operator difference for determination of behenic acid in edible vegetable oils by using convolutional neural network and polynomial correction.

A novel polynomial correction method, order-adaptive polynomial correction (OAPC), was proposed to correct reflectance spectra with operator differences, and convolutional neural network (CNN) was used to develop analysis model to predict behenic acid in edible oils. With application of OAPC, CNN performed well with coefficient of determination of correction (R2cor) of 0.8843 and root mean square error of correction (RMSEcor) of 0.1182, outperforming partial least squares regression, support vector regression and random forest with OAPC, as well as the cases without OAPC. Based on 16 effective wavelengths selected by combination of bootstrapping soft shrinkage, random frog and Pearson's correlation, CNN and OAPC exhibited excellent performance with R2cor of 0.9560 and RMSEcor of 0.0730. Meanwhile, only 5% correction samples were selected by Kennard-Stone for OAPC. Overall, the proposed method could alleviate the impact of operator differences on spectral analysis, thereby providing potential to correct differences from measurement instruments or environments.

Application of Raman spectroscopy in the rapid detection of waste cooking oil.

Raman spectra were used to distinguish waste cooking oil from edible vegetable oils. Signals at 869, 969, 1302 and 1080 cm-1 were found to be crucial to distinguish waste cooking oil from five edible oils using PCA. When waste cooking oil was added to soybean or olive oil, PCA could separate adulterated and pure oils, when the adulteration proportions reached 10% and 20%, respectively. Peaks at 969 (R2 > 0.951), 1267 (R2 = 0.987) and 1302 (R2 > 0.984) cm-1 responded linearly to adulteration. Heating assays and 1H NMR analysis revealed that differences between the Raman spectra of waste cooking oil and edible oils at 969 and 1267 cm-1 were directly related to heat treatment. This work highlights the potential for Raman spectroscopy to detect waste cooking oil.

[Chloropropanol and glycidyl esters content in edible vegetable oils in China in 2015-2017].

OBJECTIVE: To investigate the occurrence data for fatty acid esters of chloropropanol and glycidyl in edible vegetable oils purchased in China. METHODS: The 1309 samples of edible vegetable oil were collected and the data of chloropropanol and glycidyl were detected by the gas chromatography-mass spectrometry from 2015 to 2017. RESULTS: The detection rate of 3-monochloropropanediol esters in vegetable oils was 81. 83% with the mean level of 1. 21 mg/kg. The mean content of tea-seed oil was significantly higher than that of other varieties, followed by peanut oil(1. 36 mg/kg), rapeseed oil(1. 12 mg/kg). The sunflower seed oil has the lowest mean content(0. 54 mg/kg). The detection rate of 2-monochloropropanediol esters in vegetable oils was 82. 84% with the mean level of 0. 39 mg/kg. The content of peanut oil was significantly higher than that of other varieties, followed by blended oil(0. 30 mg/kg) and soybean oil(0. 25 mg/kg). There was no significant difference with rapeseed oil(0. 66 mg/kg). The exceeding rate of glycidyl ester was 19. 90% with the mean level of 0. 68 mg/kg. The average content of glycidyl ester in blended oil(0. 78 mg/kg) was significantly higher than that in peanut oil(0. 54 mg/kg). There was no significant difference among other varieties. CONCLUSION: The pollution of chloropropanol esters is common in edible vegetable oils in China. The contamination is different in kinds of edible oils.

[Investigation of benzo(a)pyrene contamination in edible vegetable oil sold in Henan Province from 2017 to 2019].

OBJECTIVE: To investigate the contamination of benzo(a)pyrene in edible vegetable oil from Henan Province. METHODS: A total of 1190 edible vegetable oil samples from Henan Province were collected. The concentration of benzo(a)pyrene was examined by high performance liquid chromatography. RESULTS: The concentration of benzo(a)pyrene in prepackaged edible vegetable oils was <0. 3-63. 5 µg/kg with an average of 1. 5 µg/kg. The detection rate of benzo(a)pyrene in samples was 80. 0%, and the over standard rate was 0. 6%. In terms of subclasses of vegetable oil, the sesame seed oil samples were most seriously contaminated with benzo(a)pyrene. The risk of the benzo(a)pyrene contamination of sesame seed oil produced by aqueous extraction method was higher than that by mechanical pressed method. The risk of benzo(a)pyrene contamination in sesame seed oil and rapeseed oil increased as the decrease of quality grade. CONCLUSION: The result suggested that the sesame seed oil produced by aqueous extraction method had high risk in benzo(a)pyrene contamination in Henan Province.

Cumulative risk assessment of phthalates in edible vegetable oil consumed by Chinese residents.

BACKGROUND: Phthalates have been widely used as plasticizers in various industries and are widely focused on in the international community as a result of their reproductive toxicity. Exposure of Chinese residents to phthalates via edible vegetable oil occurs often. In the present study, gas chromatography-mass spectrometry was used to detect the two main phthalates bis(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) in four major edible vegetable oil sources: an edible oil blend, soybean oil, peanut oil and rapeseed oil (a total of 1016 samples), as collected throughout China. Furthermore, cumulative risk assessment was used to estimate the reproductive health risk to Chinese residents caused by the phthalates that come from edible vegetable oils. RESULTS: Both phthalates were detected in four major edible vegetable oil sources. The phthalate with the highest detection rate was DBP (13.48%), followed by DEHP (7.78%). The results of the cumulative risk assessment showed that the hazard indices of these two phthalates in edible vegetable oils were less than 1, except in soybean oil. Nevertheless, the two phthalates had the lowest detection rates in soybean oil, which were 1.94% (DEHP) and 5.16% (DBP). In China, contamination levels of phthalates in the soils where oil crops are cultivated have a great influence on the phthalate concentrations in edible vegetable oils. CONCLUSION: It is recommended that Chinese residents who are consuming soybean oil choose well-known brands and regularly change their brand of consumption. The phthalates in edible vegetable oils pose a relatively small reproductive health risk to Chinese residents. © 2019 Society of Chemical Industry.

Assessment of quality of edible vegetable oils accessed in Gondar City, Northwest Ethiopia.

OBJECTIVE: Edible vegetable oils are prone to quality deterioration through oxidation and microbial degradation resulting in nutritional loss and off-flavors. Quality deterioration may contribute in the formation of oxidation products that are reactive and toxic, which ultimately pose health risks including cancer and inflammation. The objective of this study was to assess quality of both imported and locally made edible vegetable oils accessed in Gondar City, Ethiopia. Cross-sectional study design was used to collect 60 samples randomly; 30 from locally made (Niger seed at market 14, Niger seed at production center 11, sunflower at the market 5) and 30 from imported palm oil brands (Avena 11, Hayat 4, Jersey 5 and Chef 10). RESULTS: The mean value for: moisture content (%) (0.333 ± 0.08 while 0.089 ± 0.11), specific-gravity (0.823 ± 0.14 and 0.807 ± 0.115), peroxide value (15.09 ± 1.61 and 7.05 ± 0.102 mill-equivalents of oxygen/kg), acid value (2.43 ± 0.9 and 0.98 ± 0.23 mg KOH/g oil) and iodine value (115.63 ± 6.77 and 21.8 ± 3.4 g I2/100 g oil) for local and imported edible oils, respectively. The results highlight that all rancidity quality parameters of the locally made oil samples were not within the joint WHO/FAO standards whilst the imported oils showed a greater fatty acid saturation.

Non-edible vegetable oil-based feedstocks capable of bio-lubricant production for automotive sector applications-a review.

Fossil fuel resource is on the draining stage which leads to an increment in the cost of the petroleum products. Nowadays, research is focused on the development of environment-friendly lubricants which are derivatives of renewable sources. Bio-lubricants based on non-edible oil sources are environmentally friendly because they are non-hazardous and biodegradable and no emission of toxic gases were detected when they are used. This study involves the characterizations and advantages, as well as utilization of inedible plant oil-driven bio-lubricants as an alternative for tribological applications. This report also presents the status of the global lubricant market as well as the potential outlook of the bio-lubricants for their future usage. Non-edible plant oil-driven bio-lubricants bear high viscosity, high lubricity, and high viscosity index which can enhance the equipment service life and deserve the ability to carry the high load and results in a minimum amount of metal traces during combustion while applied to engines. Beside their advantages, some of the disadvantages are also there which can be addressed by the employment of certain additives available according to the applications. The detailed study about the different additives utilized during their use in the internal combustion engine is also described in detail during this study. This study provides a detailed description of the possibilities associated with bio-lubricant based on non-edible oil feedstocks to the automotive sector applications.

[Determination of organo-tin residues in edible vegetable oil by positive chemical ionization-gas chromatography-mass spectrometry].

For the determination of organo-tin residues in edible vegetable oil, a method was developed based on gas chromatography-mass spectrometric (GC-MS) with positive chemical ionization (PCI). The edible oil samples were first dissolved by cyclohexane-ethyl acetate (1:1, v/v), and then purified by gel permeation chromatography (GPC). After derivatization by sodium tetraethylborate, the samples were analyzed by GC-MS with PCI source in the single ion monitor (SIM) mode. The seven organo-tin compounds showed good linear relationships in the range of 20-2000 µg/L and the correlation coefficients exceeded 0.99. The limits of quantitation (LOQs) and the average recoveries of the seven organo-tin compounds were 0.3-1.2 µg/kg and 66.2%-103.2%, respectively, and the relative standard deviations were less than 11.5% at three spike levels (0.05, 0.10, and 0.20 mg/kg). The method showed good linearity and high sensitivity and can be used for the determination of organo-tin residues in edible vegetable oil.

Ultrasound-assisted surfactant-enhanced emulsification microextraction using a magnetic ionic liquid coupled with micro-solid phase extraction for the determination of cadmium and lead in edible vegetable oils.

A novel ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) using a magnetic ionic liquid (MIL) coupled with micro-solid phase extraction was developed for the preconcentration of cadmium and lead in edible vegetable oils prior to analysis by graphite furnace atomic absorption spectrometry. MIL [C4mim] [FeCl4] was used as the extractant, non-ionic surfactant Triton X-100 as the emulsifier and Fe3O4 nanoparticles as the sorbent, while ultrasound was applied to assist the dispersion of the extractant and accelerate the mass transfer process. By mixing Fe3O4 nanoparticles with the MIL after UASEME, the phase separation time was shortened and the separation can be simplified by applying an external magnetic field. Under the optimized conditions, the proposed method was validated and the results demonstrated that the method can produce satisfactory linearity, sensitivity, reproducibility and recovery for the analytes. Finally, the method was successfully applied for the determination of Cd and Pb in edible vegetable oil samples.

Synchronous front-face fluorescence spectroscopy for authentication of the adulteration of edible vegetable oil with refined used frying oil.

Synchronous front-face fluorescence spectroscopy has been developed for the discrimination of used frying oil (UFO) from edible vegetable oil (EVO), the estimation of the using time of UFO, and the determination of the adulteration of EVO with UFO. Both the heating time of laboratory prepared UFO and the adulteration of EVO with UFO could be determined by partial least squares regression (PLSR). To simulate the EVO adulteration with UFO, for each kind of oil, fifty adulterated samples at the adulterant amounts range of 1-50% were prepared. PLSR was then adopted to build the model and both full (leave-one-out) cross-validation and external validation were performed to evaluate the predictive ability. Under the optimum condition, the plots of observed versus predicted values exhibited high linearity (R(2)>0.96). The root mean square error of cross-validation (RMSECV) and root mean square error of prediction (RMSEP) were both lower than 3%.

Two-dimensional linear discriminant analysis for classification of three-way chemical data.

The two-dimensional linear discriminant analysis (2D-LDA) algorithm was originally proposed in the context of face image processing for the extraction of features with maximal discriminant power. However, despite its promising performance in image processing tasks, the 2D-LDA algorithm has not yet been used in applications involving chemical data. The present paper bridges this gap by investigating the use of 2D-LDA in classification problems involving three-way spectral data. The investigation was concerned with simulated data, as well as real-life data sets involving the classification of dry-cured Parma ham according to ageing by surface autofluorescence spectrometry and the classification of edible vegetable oils according to feedstock using total synchronous fluorescence spectrometry. The results were compared with those obtained by using the spectral data with no feature extraction, U-PLS-DA (Partial Least Squares Discriminant Analysis applied to the unfolded data), and LDA employing TUCKER-3 or PARAFAC scores. In the simulated data set, all methods yielded a correct classification rate of 100%. However, in the Parma ham and vegetable oil data sets, better classification rates were obtained by using 2D-LDA (86% and 100%), compared with no feature extraction (76% and 77%), U-PLS-DA (81% and 92%), PARAFAC-LDA (76% and 86%) and TUCKER3-LDA (86% and 93%).

Characterization of volatile components in four vegetable oils by headspace two-dimensional comprehensive chromatography time-of-flight mass spectrometry.

Edible oil adulteration is the biggest source of food fraud all over the world. Since characteristic aroma is an important quality criterion for edible oils, we analyzed volatile organic compounds (VOCs) in four edible vegetable oils (soybean, peanut, rapeseed, and sunflower seed oils) by headspace comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (Headspace-GC×GC-TOFMS) in this study. After qualitative and quantitative analysis of VOCs, we used unsupervised (PCA) and supervised (Random forests) multivariate statistical methods to build a classification model for the four edible oils. The results indicated that the four edible oils had their own characteristic VOCs, which could be used as markers to completely classify these four edible oils into four groups.