Rapid detection of adulteration of cold pressed sesame oil adultered with hazelnut, canola, and sunflower oils using ATR-FTIR spectroscopy combined with chemometric

Research advances in detection of food adulteration and application of MALDI-TOF MS: A review

Food adulteration and illegal supplementations have always been one of the major problems in the world. The threat of food adulteration to the health of consumers cannot be ignored. Food of questionable origin causes economic losses to consumers, but the potential health risks cannot be ignored. However, the traditional detection methods are time-consuming and complex. This review mainly discusses the types of adulteration and technologies used to detect adulteration. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is also emphasized in the detection of adulteration and authenticity of origin analysis of various types of food (milk, meat, edible oil, etc.), and the future application direction and feasibility of this technology are analyzed. On this basis, MALDI-TOF MS was compared with other detection methods, highlighting the advantages of this technology in the detection of food adulteration. The future development prospect and direction of this technology are also emphasized.

Analytical approaches for the determination of adulterated animal fats and vegetable oils in food and non-food samples

Edible oils and fats are crucial components of everyday cooking and the production of food products, but their purity has been a major issue for a long time. High-quality edible oils are contaminated with low- and cheap-quality edible oils to increase profits. The adulteration of edible oils and fats also produces many health risks. Detection of main and minor components can identify adulterations using various techniques, such as GC, HPLC, TLC, FTIR, NIR, NMR, direct mass spectrometry, PCR, E-Nose, and DSC. Each detection technique has its advantages and disadvantages. For example, chromatography offers high precision but requires extensive sample preparation, while spectroscopy is rapid and non-destructive but may lack resolution. Direct mass spectrometry is faster and simpler than chromatography-based MS, eliminating complex preparation steps. DNA-based oil authentication is effective but hindered by laborious extraction processes. E-Nose only distinguishes odours, and DSC directly studies lipid thermal properties without derivatization or solvents. Mass spectrometry-based techniques, particularly GC-MS is found to be highly effective for detecting adulteration of oils and fats in food and non-food samples. This review summarizes the benefits and drawbacks of these analytical approaches and their use in conjunction with chemometric tools to detect the adulteration of animal fats and vegetable oils. This combination provides a powerful technique with enormous chemotaxonomic potential that includes the detection of adulterations, quality assurance, assessment of geographical origin, assessment of the process, and classification of the product in complex matrices from food and non-food samples.

Comparison evaluation pretreatments on the quality characteristics, oxidative stability, and volatile flavor of walnut oil

In this study, we applied various thermal pretreatment methods (e.g., hot-air, microwave, and stir-frying) to process walnut kernels, and conducted comparative analysis of the physicochemical properties, nutritional components, in vitro antioxidant activity, and flavor substances of the extracted walnut oil (WO). The results indicated that, thermal pretreatment significantly increased the extraction of total trace nutrients (e.g., total phenols, tocopherols, and phytosterols) in WO. The WO produced using microwave had 2316.71 mg/kg of total trace nutrients, closely followed by the stir-frying method, which yielded an 11.22% increase compared to the untreated method. The WO obtained by the microwave method had a higher Oxidative inductance period (4.05 h) and oil yield (2.48%). After analyzing the flavor in WO, we found that aldehydes accounted for 28.77% of the 73 of volatile compounds and 58.12% of the total flavor compound content in microwave-pretreated WO, these percentages were higher than those recorded by using other methods. Based on the comprehensive score obtained by the PCA, microwave-pretreatment might be a promising strategy to improve the quality of WO based on aromatic characteristics.

Physicochemical and antimicrobial properties of soy protein isolate films incorporating high internal phase emulsion loaded with thymol

Oil-in-water (O/W) high internal phase (HIP) emulsion was prepared to investigate its effects on the physicochemical properties and antimicrobial properties of soy protein isolate (SPI)-based films. The particle size and migration degree of oil droplets in the SPI film-forming solution with HIP emulsion and the films were lower than those with conventional O/W emulsion or oil. The SPI-based emulsion films with HIP emulsion containing 30 % oil had the lowest water vapor permeability (1.15 × 10-10 g·m-1·s-1·Pa-1), glass transition temperature (40.93 °C) and tensile strength (4.47 MPa), and the highest transparency value (12.87) and elongation at break (160.83 %). The antimicrobial test of the SPI-based emulsion films loaded with thymol showed that the thymol encapsulation efficiency, sustained release effect, and growth inhibition effect on microbes were higher for the films with HIP emulsion than those for the films with O/W emulsion or oil.

Classification of oils and margarines by FTIR spectroscopy in tandem with machine learning

This study assessed the combined utility of ATR-FTIR spectroscopy and machine learning (ML) techniques for identifying and classifying pure njangsa seed oil (NSO), palm kernel oil (PKO), coconut oil (CCO), njangsa seed oil-palm kernel oil (NSOPKO) and njangsa seed oil-coconut oil (NSOCCO) margarine. Additionally, it quantified the degree of adulteration in each oil and margarine using ML regression models and sunflower oil and canola-flaxseed oil margarine as adulterants. Fingerprints of the oils and the margarines derived in the spectra region 4000-600 cm-1 were combined with ML models. The first two principal components explained 99.4% and 98% of the variance of pure oils and margarines and 90.1, 88.3, 88, 97.3 and 98.3% of adulterated PKO, NSO, CCO, NSOCCO and NSOPKO, respectively while enabling visualization. Pure margarines were classified accurately (100%) in all models. KNN was most effective in classifying pure oil at 97% followed by LR (93%), SVM (83%), LightGBM (53%) and DT (50%). The R2 obtained from all the models for adulterated PKO, NSO, CCO, NSOPKO and NSOCCO ranged from 59-99%, 55-99%, 45-94%, 69-98% and 59-94%, respectively. SVM and DT underperformed, while KNN was the best model.

A methodological approach to preprocessing FTIR spectra of adulterated sesame oil

Fourier transform infrared (FTIR) spectroscopy is established as an effective and fast method for the confirmation of the authenticity of food and among other, edible oils. However, no standard procedure is available for applying preprocessing as a vital step in obtaining accurate results from spectra. This study proposes a methodological approach to preprocessing FTIR spectra of sesame oil adulterated with vegetable oils (canola oil, corn oil, and sunflower oil). The primary preprocessing methods investigated are orthogonal signal correction (OSC), standard normal variate transformation (SNV), and extended multiplicative scatter correction (EMSC). Other preprocessing methods are used both as standalone methods and in combination with the primary preprocessing methods. The preprocessing results are compared using partial least squares regression (PLSR). OSC alone or with detrending were the most accurate in predicting the adulteration level of sesame oil, with a maximum coefficient of prediction (R²_p) range of 0.910 to 0.971 for different adulterants.

Effects of free and encapsulated Siah-e-Samarghandi grape seed extract on the physicochemical, textural, microbial, and sensorial properties of UF-Feta cheese

The current study was conducted to elucidate the impact of grape seed extract (SE) and microencapsulated seed extract (MSE) addition to UF-Feta cheese. The SE was encapsulated in maize starch, alginate, and canola oil using the emulsion technique. The SE and MSE characteristics were evaluated. The products were subjected to physicochemical (pH, titrable acidity, color, texture, and sensory properties), microbiological analysis (starter count), and lipid oxidation test (proxide, acid degree, and ansidine value) during 60 days of storage. The main phenol component in the SE was catechin (419.04 mg/L), gallic acid (319.63 mg/L), and chlorogenic acid (4.19 ± 0.002 mg/L). The antioxidant value was 157.80 mg/L. The MSE was elliptical in shape with a 24.29 μm diameter. The efficiency of microencapsulation was 53.86%. The addition of SE and MSE had no significant effect on pH and acidity, but lipolysis decreased based on acid degree value (0.7%; p > .05). The increasing trend of peroxide values was 172.54%, 145.68%, and 118.75% for C, SE, and MSE samples, respectively, and 35.68%, 32.28%, and 17.24% for the P-anisidine values during the storage time. Therefore, fat oxidation was reduced in the supplemented cheese. Nevertheless, the supplemented cheese had limited color alterations. The MSE and SE did not affect the survival rates of the starter count. The SE and MSE had a less rigid structure. The hardness (2748.0 g) and chewiness (57.45 mJ) values in SE cheese had the greatest value among the samples. All sensory parameters were lowest in MSE cheese. In short, encapsulation showed suitable properties for SE to apply in UF-Feta cheese.

Bigel formulations based on sesame oleogel with probiotics alginate hydrogel: A novel structure for nutritious spreadable butter

As a replacement for saturated fats, bigel butter spread (BgBs) based on sesame oleogel and alginate hydrogel was developed. Morphology, oxidative stability, microbiological, chemical, and sensory analysis were assessed. The results demonstrated that unsaturated fatty acids were higher in cinnamon (73.87 %) than in plain (71.57 %) BgBs. The peroxide value was higher in plain (5.25 meqO₂/kg) than in cinnamon BgBs (4.29 meqO₂/kg). Cinnamon BgBs had 44.44 % more antioxidant activity compared to plain BgBs (40.20 %). Moreover, BgBs products kept their probiotic counts at >7 log cycles. The cinnamon BgBs had a lower microbial load than plain BgBs. The chemical composition of the BgBs products did not change significantly. But the pH values slightly dropped with the storage time. The sensory evaluation of plain and cinnamon BgBs did not significantly differ from one another. However, the period of storage and the addition of the cinnamon oil significantly affected the flavor ratings.

Impact of Metal Nanoparticles on the Phytochemical and Antioxidative Properties of Rapeseed Oil

The agricultural uses of nanoparticles continue to be considered as innovative methods that require more in-depth research into their impact on product quality. In our study, we investigated the effects of fertilizers containing metal nanoparticles (silver AgNPs and copper CuNPs) during the plant growth stage of winter rape cultivation, and in most experimental variants, with the exception of the (x2) application of AgNPs, we observed a decrease in the mass of one thousand seeds (MTS). The obtained result was 11.55% higher relative to the control sample in 2019, and also increased after the (x1) 4.36% and (x2) 11.11% application of CuNPS in 2020. The analyzed oxidative stability of the oil increased in both experimental years (2019-2020), with the highest values recorded after the (x1) and (x2) application of CuNPS-4.94% and 8.31%, respectively, in the first year of cultivation, and after the (x2) application of CuNPS-12.07% in the subsequent year. It was also observed that the content of polyphenols, flavonoids, squalene, tocopherols α and δ, chlorophylls, and carotenoids increased in the oil. Moreover, spectral FTIR analysis was performed on the oil samples obtained from cultivations sprayed with solutions containing Ag or Cu nanoparticles and revealed changes in several spectral regions with the maxima at ~1740, 1370, 1230, and ~1090 cm^-1. Additionally, a FTIR analysis conducted in combination with multivariate analysis allowed us to classify the studied oils into the most similar groups and to study the structure of data variability. The conducted analyses revealed that the use of nanoparticles resulted in decreased size of the produced seeds and improved antioxidative properties of rapeseed oil.

Authenticity Assessment from Sesame Seeds to Oil and Sesame Products of Various Origin by Differential Scanning Calorimetry

The aim of this study was to conduct thermal characterization of sesame seeds and oils from various geographical origins (Ethiopia, India, Nigeria, Sudan, Turkey), different method of extraction (hexane and cold-pressing), and different types of derived products (halva and tahini). Thermal characterization was investigated using differential scanning calorimetry (DSC), which showed that origin of the seeds has no influence on the melting profile of sesame oil (peak temperature and enthalpy). Method of extraction (hexane and cold-pressing) influenced the peak temperatures of the resulting oils (p ≤ 0.05). The addition of 20% of palm olein to pure sesame oil influenced the significant changes in thermodynamic parameters such as peak temperature (Tm2), which was lowered from −5.89 °C to −4.99 °C, peak half width (T1/2), elevated from 3.01 °C to 4.52 °C, and the percentage of first peak area (% peak 1) lowered from 87.9 to 73.2% (p ≤ 0.05). The PCA method enabled to distinguish authentic and adulterated sesame oils of various origins. There were no significant differences in thermal properties among the products (halva, tahini) and the authentic sesame oil (p > 0.05). The obtained results showed DSC feasibility to characterize sesame oil and sesame products in terms of authenticity.

Food inauthenticity: Authority activities, guidance for food operators, and mitigation tools

Historically, food fraud was a major public health concern which helped drive the development of early food regulations in many markets including the US and EU market. In the past 10 years, the integrity of food chains with respect to food fraud has again been questioned due to high profile food fraud cases. We provide an overview of the resulting numerous authoritative activities underway within different regions to counter food fraud, and we describe the guidance available to the industry to understand how to assess the vulnerability of their businesses and implement appropriate mitigation. We describe how such controls should be an extension of those already in place to manage wider aspects of food authenticity, and we provide an overview of relevant analytical tools available to food operators and authorities to protect supply chains. Practical Application: Practical Application of the provided information by the food industry in selecting resources (guidance document, analytical methods etc.).

Influence of ozonation and roasting on functional, microstructural, textural characteristics, and aflatoxin content of groundnut kernels

The present study was conducted to evaluate the influence of ozonation, roasting and their combination on the moisture content, color, functional, structural, textural components, and aflatoxins in groundnut kernels. Samples were subjected to three treatments namely, dry roasting (R): 166°C for 7 min; gaseous ozone treatment (O): 6 mg/L for 30 min; combined ozonation-roasting (OR): gaseous ozonation at 6 mg/L for 30 min followed by dry roasting at 166°C for 7 min. The ozonated-roasted samples had the lowest moisture content (3.45%), the highest total phenolic content (4.18 mg gallic acid equivalents/100 g), and antioxidants capacity (69.59%). The treatments did not induce significant changes in color of kernels (p < .05). Scanning electron microscopy indicated cracking of granules in roasted and swelling in ozonated kernels whereas more uniform orientation of granules was observed in ozonated-roasted kernels. Roasted and ozonated kernels indicated a significant reduction of fracturability force to 54.60 and 14.11%, respectively, whereas ozonated-roasted samples demonstrated a nonsignificant increase (4.37%). An increase in wave number of ozonated samples to 3,289.37 cm^-1 in Fourier transform infrared (FTIR) spectrum (FTIR) indicated stretching in OH groups. FTIR spectrum of ozonated-roasted kernels suggested the formation of a new compound with CC and CC groups. The major aflatoxin B1 was reduced to maximum, that is, 100% in ozonated-roasted kernels followed by ozonated (80.95%) and roasted (57.14%) samples. The findings indicate that the ozonation-roasting treatment had a prominent role in the enhancement of functional compounds, structural and textural attributes along with the considerable reduction in aflatoxin content.

Characterizing the Bioactive Ingredients in Sesame Oil Affected by Multiple Roasting Methods

Roasting is an important step in sesame (Sesamum indicum L.) processing. The current research was undertaken to evaluate the oil content, fatty acid (FA) profiles, and physicochemical characteristics of oil recovered from sesame roasted by different methods (cooker oven, stovetop pan, microwave, and electric frying pan). Roasting sesame seeds changed their oil content according to the roasting method used, with content ranging from 49.83% in control to 59.85% in the roasting by microwave. In oils recovered from raw or roasted seeds, seven fatty acids were obtained through gas chromatography. Changes in the fatty acid profiles occurred in all the treatments, and the total unsaturated fatty acid content was higher than that of saturated fatty acids. The obtained peroxide number of sesame oils was inside the rate of 3.90 meq/kg oil for microwave treatment versus 1.59 meq/kg oil for unroasted. The highest acid value was with the stovetop pan treatment at 3.78 mg/g, followed by the microwave treatment at 3.24 mg/g; the oven treatment gave the lowest value at 1.66 mg/g. The lowest iodine value was observed with the electric frying pan treatment (102.30/100 g oil), and phytosterols were most abundant with the microwave treatment. Moreover, the phenolic and flavonoid contents and antioxidant activity were the highest with the microwave roasting. The FTIR spectrum illustrated slight differences in peaks intensity (1738, 1454, 1151, 710 cm⁻¹) between the roasting methods used. The finding of the current investigation of roasting methods was that the fatty acid profiles were across methods. As is clear from the obtained results, the microwave roasting treatment is the favoured roasting method for the healthiest sesame seed oil contents. Sesame seeds are considered a significant and abundant resource with numerous beneficial nutrients that positively affect human health.

Highly efficient authentication of edible oils by FTIR spectroscopy coupled with chemometrics

A novel improved method for the authentication of edible oil samples based on Fourier-transform infrared (FTIR) spectroscopy coupled with chemometrics has been developed. A discrimination analysis model has been developed. On this basis, 100% correct classification of 135 samples from eleven species has been achieved. Recognition rates with respect to external validation for 91 pure oil samples and 231 blend samples were 100% and 92.6%, respectively. A general quantitative model for detecting edible oil adulteration (taking Camellia oil as an example) has also been built. An optimal backward interval partial least-squares model, based on the spectral regions ν = 3100-2900, 1800-1700, 1500-1400, and 1200-1100 cm^-1, has been determined, giving good performances. A specific sub-model using a single adulterant oil has also been constructed, which showed higher prediction accuracy. Based on the developed qualitative and quantitative FTIR methods, adulterant oils in Camellia blends could be rapidly detected, effectively differentiated, and accurately quantified.

Advanced process analytical tools for identification of adulterants in edible oils - A review

This review summarizes the use of spectroscopic processes-based analytical tools coupled with chemometric techniques for the identification of adulterants in edible oil. Investigational approaches of process analytical tools such asspectroscopy techniques, nuclear magnetic resonance (NMR), hyperspectral imaging (HSI), e-tongue and e-nose combined with chemometrics were used to monitor quality of edible oils. Owing to the variety and intricacy of edible oil properties along with the alterations in attributes of the PAT tools, the reliability of the tool used and the operating factors are the crucial components which require attention to enhance the efficiency in identification of adulterants. The combination of process analytical tools with chemometrics offers a robust technique with immense chemotaxonomic potential. These involves identification of adulterants, quality control, geographical origin evaluation, process evaluation, and product categorization.

Edible Oils Adulteration: A Review on Regulatory Compliance and Its Detection Technologies

Various events of edible oils adulteration with inferior ingredients were reported regularly in recent years. This review is aimed to provide an overview of edible oils adulteration practices, regulatory compliance and detection technologies. Many detection technologies for edible oils adulteration were developed in the past such as methods that are based on chromatography or spectroscopy. Electrochemical sensors like electric nose and tongue are also gaining popularity in the detection of adulterated virgin olive oil and virgin coconut oil. It can be concluded that these detection technologies are essential in the combat with food adulterers and can be improved.

Metabolomics Approaches for the Comprehensive Evaluation of Fermented Foods: A Review

Fermentation is an important process that can provide new flavors and nutritional and functional foods, to deal with changing consumer preferences. Fermented foods have complex chemical components that can modulate unique qualitative properties. Consequently, monitoring the small molecular metabolites in fermented food is critical to clarify its qualitative properties and help deliver personalized nutrition. In recent years, the application of metabolomics to nutrition research of fermented foods has expanded. In this review, we examine the application of metabolomics technologies in food, with a primary focus on the different analytical approaches suitable for food metabolomics and discuss the advantages and disadvantages of these approaches. In addition, we summarize emerging studies applying metabolomics in the comprehensive analysis of the flavor, nutrition, function, and safety of fermented foods, as well as emphasize the applicability of metabolomics in characterizing the qualitative properties of fermented foods.

Advanced techniques in edible oil authentication: A systematic review and critical analysis

Adulteration of edible substances is a potent contemporary food safety issue. Perhaps the overt concern derives from the fact that adulterants pose serious ill effects on human health. Edible oils are one of the most adulterated food products. Perpetrators are adopting ways and means that effectively masks the presence of the adulterants from human organoleptic limits and traditional oil adulteration detection techniques. This review embodies a detailed account of chemical, biosensors, chromatography, spectroscopy, differential scanning calorimetry, non-thermal plasma, dielectric spectroscopy research carried out in the area of falsification assessment of edible oils for the past three decades and a collection of patented oil adulteration detection techniques. The detection techniques reviewed have some advantages and certain limitations, chemical tests are simple; biosensors and nuclear magnetic resonance are rapid but have a low sensitivity; chromatography and spectroscopy are highly accurate with a deterring price tag; dielectric spectroscopy is rapid can be portable and has on-line compatibility; however, the results are susceptible to variation of electric current frequency and intrinsic factors (moisture, temperature, structural composition). This review paper can be useful for scientists or for knowledge seekers eager to be abreast with edible oil adulteration detection techniques.

Chia Oil Adulteration Detection Based on Spectroscopic Measurements

Chia oil is a valuable source of omega-3-fatty acids and other nutritional components. However, it is expensive to produce and can therefore be easily adulterated with cheaper oils to improve the profit margins. Spectroscopic methods are becoming more and more common in food fraud detection. The aim of this study was to answer following questions: Is it possible to detect chia oil adulteration by spectroscopic analysis of the oils? Is it possible to identify the adulteration oil? Is it possible to determine the amount of adulteration? Two chia oils from local markets were adulterated with three common food oils, including sunflower, rapeseed and corn oil. Subsequently, six chia oils obtained from different sites in Kenya were adulterated with sunflower oil to check the results. Raman, NIR and fluorescence spectroscopy were applied for the analysis. It was possible to detect the amount of adulterated oils by spectroscopic analysis, with a minimum R² of 0.95 for the used partial least square regression with a maximum RMSEP_range of 10%. The adulterations of chia oils by rapeseed, sunflower and corn oil were identified by classification with a median true positive rate of 90%. The training accuracies, sensitivity and specificity of the classifications were over 90%. Chia oil B was easier to detect. The adulterated samples were identified with a precision of 97%. All of the classification methods show good results, however SVM were the best. The identification of the adulteration oil was possible; less than 5% of the adulteration oils were difficult to detect. In summary, spectroscopic analysis of chia oils might be a useful tool to identify adulterations.

Detection of glibenclamide adulterated in antidiabetic Chinese patent medicine by attenuated total reflectance -infrared spectroscopy and chemometrics

There have been many reports of adulterated Chinese patent medicine with synthetic prescription that are claimed to be "pure natural". The present work investigates the feasibility of combining attenuated total reflectance-Mid-infrared (ATR-MIR) spectroscopy and several interval-based PLS algorithms for detecting the glibenclamide illegally adulterated in antidiabetic Chinese patent medicine (Jiangtangning). The full-spectrum PLS, four kinds of traditional interval PLS algorithms (iPLS, biPLS, siPLS and mwPLS) and a modified algorithm, i.e., a combination of mwPLS and window size optimization, named cmwPLS, were used for building calibration models. A total of 21 samples adulterated with 0-3.5% glibenclamide were prepared. The dataset was equally split into a training set and a test set for building and testing the prediction models, respectively. For those interval-based PLS, the whole wavenumber axis was divided into 20 sub-intervals. In terms of the prediction on the test set, the new cmwPLS produce the best model, followed by mwPLS. The modified algorithm can optimize automatically the window width (i.e., the number of adjacent variables used for modeling) and position. It can be concluded that cmwPLS coupled with ATR-MIR technique is a good alternative to other traditional chemical analysis for detecting the adulteration of Chinese patent medicine.

Vegetable oils: Are they true? A point of view from ATR-FTIR, 1H NMR, and regiospecific analysis by 13C NMR

Problems related to oil authenticity make it difficult to obtain the benefits associated with each type of vegetable oil. Fraudulent practices have been revealed by several targeted and nontargeted methods. In this paper, spectroscopic techniques (FT-IR, ¹H NMR, and ¹³C NMR) were applied to determine the chemical profiles of 23 Brazilian commercial vegetable oils obtained from five different high-value aggregated matrices (andiroba, babassu, baru, castor, and sweet almond oils) and investigate their adulteration, by comparison with the corresponding reference samples. Each technique is useful for the particular information it provides: differences in free fatty acids by FT-IR; adulteration with omega-3-enriched oils by ¹H NMR, and adulteration of unsaturated-enriched oil with another unsaturated oil without linoleic acid by regiospecific analysis. Our findings highlight the importance of fusion-based methods in providing precise information for use in oil quality authentication.

An overview of recent advances and applications of FT-IR spectroscopy for quality, authenticity, and adulteration detection in edible oils

Authenticity and adulteration detection are primary concerns of various stakeholders, such as researchers, consumers, manufacturers, traders, and regulatory agencies. Traditional approaches for authenticity and adulteration detection in edible oils are time-consuming, complicated, laborious, and expensive; they require technical skills when interpreting the data. Over the last several years, much effort has been spent in academia and industry on developing vibrational spectroscopic techniques for quality, authenticity, and adulteration detection in edible oils. Among them, Fourier transforms infrared (FT-IR) spectroscopy has gained enormous attention as a green analytical technique for the rapid monitoring quality of edible oils at all stages of production and for detecting and quantifying adulteration and authenticity in edible oils. The technique has several benefits such as rapid, precise, inexpensive, and multi-analytical; hence, several parameters can be predicted simultaneously from the same spectrum. Associated with chemometrics, the technique has been successfully implemented for the rapid detection of adulteration and authenticity in edible oils. After presenting the fundamentals, the latest research outcomes in the last 10 years on quality, authenticity, and adulteration detection in edible oils using FT-IR spectroscopy will be highlighted and described in this review. Additionally, opportunities, challenges, and future trends of FT-IR spectroscopy will also be discussed.

Classification of different liquid milk by near-infrared spectroscopy and ensemble modeling

Dairy products are necessary components of a healthy diet for human and nowadays, liquid milk become very popular because of its convenience. The identification of a brand of liquid milk is of importance. In this study, near-infrared (NIR) spectroscopy is used for rapid and objective classification of different brands of liquid milk. Chemometric methods including extreme learning machine (ELM) and its ensemble version (EELM) are investigated and compared. A dataset containing 144 samples from 6 brands are collected for experiment. A model-independent filter algorithm, i.e., relief-based feature selection, was used for variable reduction. Principal component analysis (PCA) is used as a tool of exploratory analysis for visualizing the difference among liquid milk samples of different brands. All samples were divided into three subsets, i.e., the training set, validation set and test set, for constructing, optimizing and testing the model, respectively. The model developed by the EELM procedure achieved 100% of classification accuracy, indicating that NIR spectroscopy combined with variable reduction and the EELM algorithm is feasible for classifying the brands of liquid milk.

Sesame Oil (Sesamum Indicum L.) as a New Challenge for Reinforcement of Conventional Glass Ionomer Cement, Could It Be?

Purpose

Despite the advantages of glass ionomer cement (GIC) including chemical bonding to the tooth structure and fluoride release, its low-grade mechanical properties make it a topic for research. Accordingly, this study was conducted to assess the ability of sesame oil as a natural bioactive additive to reinforce conventional glass ionomer cement.

Materials and Methods

Sesame oil was blended into the liquid component of the cement in ratios of 3 and 5 (v/v%). One control and two experimental groups were enrolled in the study; I: unmodified GIC (control), II: 3 (v/v%) sesame oil-modified GICs, and III: 5(v/v%) sesame oil-modified GICs. Compressive strength, shear bond strength, diametral tensile strength, surface microhardness, surface roughness, and color stability were the parameters assessed. A representative specimen of each group was analyzed for its chemical structure by Fourier transformation infrared spectroscopy. One-way ANOVA followed by Tukey test was used to analyze the collected data of all evaluated parameters except the color stability results, which were analyzed by Student t-test at p < 0.05.

Results

Three and 5 (v/v%) sesame oil-modified GICs exhibited significant increase in their compressive strength, shear bond strength, diametral strength, and surface microhardness. Concurrently, there was a significant decrease in surface roughness (p < 0.05) in both formulations of the modified cement. Both 3 and 5 (v/v%) sesame oil-modified GICs showed a clinically acceptable color change.

Conclusions

Sesame oil seems to be a promising natural bioactive product for reinforcement of conventional GIC with a clinically agreeable esthetic.

Fatty Acid Profile of Lipid Fractions of Mangalitza (Sus scrofa domesticus) from Northern Romania: A GC-MS-PCA Approach

Mangalitza pig (Sus scrofa domesticus) becomes more popular in European countries. The goal of this study was to evaluate the fatty acid profile of the raw and thermally processed Mangalitza hard fat from Northern Romania. For the first time, the gas chromatography-mass spectrometry-Principal component analysis technique (GC-MS-PCA)—was applied to evaluate the dissimilarity of Mangalitza lipid fractions. Three specific layers of the hard fat of Mangalitza from Northern Romania were subjected to thermal treatment at 130 °C for 30 min. Derivatized samples were analyzed by GC-MS. The highest relative content was obtained for oleic acid (methyl ester) in all hard fat layers (36.1–42.4%), while palmitic acid was found at a half (21.3–24.1%). Vaccenic or elaidic acids (trans) were found at important concentrations of 0.3–4.1% and confirmed by Fourier-transform infrared spectroscopy. These concentrations are consistently higher in thermally processed top and middle lipid layers, even at double values. The GC-MS-PCA coupled technique allows us to classify the unprocessed and processed Mangalitza hard fat specific layers, especially through the relative concentrations of vaccenic/elaidic, palmitic, and stearic acids. Further studies are needed in order to evaluate the level of degradation of various animal fats by the GC-MS-PCA technique.

A simple and quick method to detect adulterated sesame oil using 3D fluorescence spectra

Adulterated sesame oil seriously damages the interests of consumers and the health of market. In this paper, a simple, fast and real-time model for identifying adulterated sesame oil (ASO) was proposed by combining 3D fluorescence spectra with wavelet moments (WMs). First, noise and data volume of the experimental data were reduced by wavelet multiresolution decomposition (WMRSD), which improved the stability and real-time of the model. Next, WMs were used to extract the features of the 3D fluorescence spectra and proved to be effective by hierarchical clustering results. Then, the qualitative quality of WMs of the same orders, different orders and the combinations were evaluated by Dunn's validity index (DVI), and the rules were given, respectively. Finally, the target WMs for identifying ASO were determined. This model is simple and fast, and expandable to online measurement, providing a reference for identification and adulteration of vegetable oils.

Total synchronous fluorescence spectroscopy coupled with deep learning to rapidly identify the authenticity of sesame oil

The quality of sesame oil (SO) has been paid more and more attention. In this study, total synchronous fluorescence (TSyF) spectroscopy and deep neural networks were utilized to identify counterfeit and adulterated sesame oils. Firstly, typical samples including pure SO, counterfeit sesame oil (CSO) and adulterated sesame oil (ASO) were characterized by TSyF spectra. Secondly, three data augmentation methods were selected to increase the number of spectral data and enhance the robustness of the identification model. Then, five deep network architectures, including Simple Recurrent Neural Network (Simple RNN), Long Short-Term Memory (LSTM) network, Gated Recurrent Unit (GRU) network, Bidirectional LSTM (BLSTM) network and LSTM fortified with Convolutional Neural Network (LSTMC), were designed to identify the CSO and trace the source with 100% accuracy. Finally, ASO samples were also 100% correctly identified by training these network architectures. These results supported the feasibility of the novel method.

Flocculation of Microcystis unicells induced by pH regulation: Mechanism and potential application

In water treatment process, Microcystis colonies can be effectively removed by coagulants. However, the use of popular coagulants could cause adverse health effects in humans or increase the amount of sludge. Meanwhile, Microcystis unicells are much more difficult to remove than colonies, due to their small size and dispersed distribution. This study proposed and analyzed the flocculation of Microcystis unicells induced by pH regulation. The particle size, zeta potential, cell viability and integrity, cytochemical changes, and cell-to-cell connections were recorded during pH regulation. Results showed that when pH was adjusted in the range of 2.5 to 2 by HCl (1.2 M), Microcystis unicells aggregated to form flocs as large as 28 μm, which are easy to remove by filtration or sedimentation. The overwhelming majority of cells were intact and inactivated in the optimal pH range (2.5-2). Thus, pH regulation is an environment-friendly and cost-effective method to remove Microcystis unicells, which can be potentially applied to water treatment.

Prediction of chemical parameters and authentication of various cold pressed oils with fluorescence and mid-infrared spectroscopic methods

It was aimed to compare the performances of two spectroscopic methods, fluorescence and mid-infrared spectroscopy, in terms of their adulteration detection and estimation of several chemical properties for various cold pressed seed oils. Spectroscopic profiles, fatty acid, free fatty acid and total phenol contents of pumpkin seed, grape seed, black cumin oil, and sesame seed oils were determined and these oils were mixed with sunflower oil at 1-50% (v/v). Both spectroscopic techniques provided comparable results for determination of adulteration of each oil type and the most successful prediction was obtained for pumpkin seed oil at levels >%1. Combined data set of oils resulted in successful quantification of their free fatty acid value, total phenol and major fatty acids contents with both spectroscopic methods regardless of oil type. Both techniques could be used as reliable, fast and environmentally friendly alternatives in the analyses of different types of seed oils.

Comprehensive Review on Application of FTIR Spectroscopy Coupled with Chemometrics for Authentication Analysis of Fats and Oils in the Food Products

Currently, the authentication analysis of edible fats and oils is an emerging issue not only by producers but also by food industries, regulators, and consumers. The adulteration of high quality and expensive edible fats and oils as well as food products containing fats and oils with lower ones are typically motivated by economic reasons. Some analytical methods have been used for authentication analysis of food products, but some of them are complex in sampling preparation and involving sophisticated instruments. Therefore, simple and reliable methods are proposed and developed for these authentication purposes. This review highlighted the comprehensive reports on the application of infrared spectroscopy combined with chemometrics for authentication of fats and oils. New findings of this review included (1) FTIR spectroscopy combined with chemometrics, which has been used to authenticate fats and oils; (2) due to as fingerprint analytical tools, FTIR spectra have emerged as the most reported analytical techniques applied for authentication analysis of fats and oils; (3) the use of chemometrics as analytical data treatment is a must to extract the information from FTIR spectra to be understandable data. Next, the combination of FTIR spectroscopy with chemometrics must be proposed, developed, and standardized for authentication and assuring the quality of fats and oils.