Chromatography in authenticity and traceability tests of vegetable oils and dairy products: a review

Comprehensive adulteration detection of sesame oil based on characteristic markers

Sesame oil has a unique flavor and is very popular in Asian countries, and this leads to frequent adulteration. In this study, comprehensive adulteration detection of sesame oil based on characteristic markers was developed. Initially, sixteen fatty acids, eight phytosterols, and four tocopherols were utilized to construct an adulteration detection model, which screened seven potentially adulterated samples. Subsequently, confirmatory conclusions were drawn based on the characteristic markers. Adulteration with rapeseed oil in 4 samples was confirmed using the characteristic marker of brassicasterol. The adulteration of soybean oil in 1 sample was confirmed using the isoflavone. The adulteration of 2 samples with cottonseed oil was demonstrated by sterculic acid and malvalic acid. The results showed that sesame oil adulteration could be detected by screening positive samples using chemometrics and verifying with characteristic markers. The comprehensive adulteration detection method could provide a system approach for market supervision of edible oils.

A review on proteomic and genomic biomarkers for gelatin source authentication: Challenges and future outlook

Biomarkers are compounds that could be detected and used as indicators of normal and/or abnormal functioning of different biological systems, including animal tissues and food matrices. Gelatin products of animal origin, mainly bovine and porcine, are currently under scrutiny mainly due to the specific needs of some sectors of the population related to religious beliefs and their dietary prohibitions, as well as some potential health threats associated with these products. Thus, manufacturers are currently in need of a reliable, convenient, and easy procedure to discern and authenticate the origin of animal-based gelatins (bovine, porcine, chicken, or fish). This work aims to review current advances in the creation of reliable gelatin biomarkers for food authentication purposes based on proteomic and DNA biomarkers that could be applied in the food sector. Overall, the presence of specific proteins and peptides in gelatin can be chemically analysed (i.e., by chromatography, mass spectroscopy, electrophoresis, lateral flow devices, and enzyme-linked immunosorbent assay), and different polymerase chain reaction (PCR) methods have been applied for the detection of nucleic acid substances in gelatin. Altogether, despite the fact that numerous methods are currently being developed for the purpose of detecting gelatin biomarkers, their widespread application is highly dependent on the cost of the equipment and reagents as well as the ease of use of the various methods. Combining different methods and approaches targeting multiple biomarkers may be key for manufacturers to achieve reliable authentication of gelatin's origin.

Quality Control and Authentication of Argan Oils: Application of Advanced Analytical Techniques

In addition to the nutritional and therapeutic benefits, Argan oil is praised for its unique bio-ecological and botanic interest. It has been used for centuries to treat cardiovascular issues, diabetes, and skin infections, as well as for its anti-inflammatory and antiproliferative properties. Argan oil is widely commercialized as a result of these characteristics. However, falsifiers deliberately blend Argan oil with cheaper vegetable oils to make economic profits. This reduces the quality and might result in health issues for consumers. Analytical techniques that are rapid, precise, and accurate are employed to monitor its quality, safety, and authenticity. This review provides a comprehensive overview of studies on the quality assessment of Moroccan Argan oil using both untargeted and targeted approaches. To extract relevant information on quality and adulteration, the analytical data are coupled with chemometric techniques.

Using HPLC with In-Column Derivatization to Authenticate Coffee Samples

Coffee is one of the world's most popular beverages, with the global coffee capsule market worth over USD 4 billion and growing. The incidence of coffee fraud is estimated to be up to one in five coffees being contaminated with cheaper blends of coffee. Given the worsening extent of climate change, coffee crop yields are harder to maintain, while demand is increasing. The 2021 Brazil frost delaying or destroying many coffee crops is an example. Hence, the incidence of coffee fraud is expected to increase, and as the market becomes more complex, there needs to be faster, easier, and more robust means of real-time coffee authentication. In this study, we propose the use of novel approaches to postcolumn derivatization (termed herein as in-column derivatization) to visualize the antioxidant profiles of coffee samples, to be later used as indicators for authentication purposes. We propose three simple mathematical similarity metrics for the real-time identification of unknown coffee samples from a sample library. Using the CUPRAC assay, and these metrics, we demonstrate the capabilities of the technique to identify unknown coffee samples from within our library of thirty.

The use of analytical techniques coupled with chemometrics for tracing the geographical origin of oils: A systematic review (2013-2020)

The global market for imported, high-quality priced foods has grown dramatically in the last decade, as consumers become more conscious of food originating from around the world. Many countries require the origin label of food to protect consumers need about true characteristics and origin. Regulatory authorities are looking for an extended and updated list of the analytical techniques for verification of authentic oils and to support law implementation. This review aims to introduce the efforts made using various analytical tools in combination with the multivariate analysis for the verification of the geographical origin of oils. The popular analytical tools have been discussed, and scientometric assessment that underlines research trends in geographical authentication and preferred journals used for dissemination has been indicated. Overall, we believe this article will be a good guideline for food industries and food quality control authority to assist in the selection of appropriate methods to authenticate oils.

Use of non-volatile compounds for the classification of specialty and traditional Brazilian coffees using principal component analysis

Coffee beans contain different volatile and non-volatile compounds that are responsible for their flavor and aroma. Herein, principal component analysis (PCA) was employed to correlate the non-volatile composition of specialty and traditional coffees with drink quality. The quantified non-volatile compounds included caffeine, chlorogenic acid, caffeic acid, and nicotinic acid in both types of coffee samples, while 5-hydroxymethylfurfural was only quantified in the specialty coffee samples. The most abundant compounds present in specialty coffees were associated with the aroma and flavor, affording a high drink quality. In traditional coffees, the most abundant compounds included nicotinic acid and caffeine, indicating a stronger roasting process, loss of sensory characteristics, and blended formulations. PCA showed a distinction between the traditional and specialty coffees such that a relationship between the contents of the compounds in each type of coffee, quality, and classification could be established.

Essential oils in vapor phase as alternative antimicrobials: A review

The antimicrobial effectiveness of essential oils (EOs) against many foodborne microorganisms when applied by direct contact has been extensively demonstrated. However, the vapor phase and volatile components present in EOs have not been thoroughly investigated; there are a small number of published reports on the antimicrobial activity of some EOs and a few of their components against selected microorganisms. It is well known that the antimicrobial activity of EOs depends mainly on their chemical composition. It is also important; however, to understand the volatility of these compounds as well as the methodologies used to evaluate the antimicrobial effectiveness of their vapor phase. This review focuses on recent research regarding the chemical composition of EOs, their biological activity and mechanisms of action, the antimicrobial activity of EOs in the vapor phase, the different techniques that have been proposed to evaluate the antimicrobial effects of EOs in the vapor phase, and actual and potential applications of EOs in the vapor phase. Although there is still no standard methodology for determining the activity of EOs in the vapor phase, results reported thus far are encouraging and suggest possible applications in food preservation.

Gelatin controversies in food, pharmaceuticals, and personal care products: Authentication methods, current status, and future challenges

Gelatin is a highly purified animal protein of pig, cow, and fish origins and is extensively used in food, pharmaceuticals, and personal care products. However, the acceptability of gelatin products greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid and protein based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review paper has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication.

Proteomics in food: Quality, safety, microbes, and allergens

Food safety and quality and their associated risks pose a major concern worldwide regarding not only the relative economical losses but also the potential danger to consumer's health. Customer's confidence in the integrity of the food supply could be hampered by inappropriate food safety measures. A lack of measures and reliable assays to evaluate and maintain a good control of food characteristics may affect the food industry economy and shatter consumer confidence. It is imperative to create and to establish fast and reliable analytical methods that allow a good and rapid analysis of food products during the whole food chain. Proteomics can represent a powerful tool to address this issue, due to its proven excellent quantitative and qualitative drawbacks in protein analysis. This review illustrates the applications of proteomics in the past few years in food science focusing on food of animal origin with some brief hints on other types. Aim of this review is to highlight the importance of this science as a valuable tool to assess food quality and safety. Emphasis is also posed in food processing, allergies, and possible contaminants like bacteria, fungi, and other pathogens.

Quality and statistical classification of Brazilian vegetable oils using mid-infrared and Raman spectroscopy

Palm oil, soy oil, sunflower oil, corn oil, castor oil, and rapeseed oil were analyzed with Fourier transform infrared (FT-IR) and FT-Raman spectroscopy. The quality of different oils was evaluated and statistically classified by principal component analysis (PCA) and a partial least squares (PLS) regression model. First, a calibration set of spectra was selected from one sampling batch. The qualitative variations in spectra are discussed with a prediction of oil composition (saturated, mono- and polyunsaturated fatty acids) from mid-infrared analysis and iodine value from FT-Raman analysis, based on ratioing the intensity of bands at given wavenumbers. A more robust and convincing oil classification is obtained from two-parameter statistical models. The statistical analysis of FT-Raman spectra favorably distinguishes according to the iodine value, while the mid-infrared spectra are most sensitive to hydroxyl moieties. Second, the models are validated with a set of spectra from another sampling batch, including the same oil types as-received and after different aging times together with a hydrogenated castor oil and high-oleic sunflower oil. There is very good agreement between the model predictions and the Raman measurements, but the statistical significance is lower for mid-infrared spectra. In the future, this calibration model will be used to check vegetable oil qualities before using them in polymerization processes.

Determination of nonprotein amino acids and betaines in vegetable oils by flow injection triple-quadrupole tandem mass spectrometry: a screening method for the detection of adulterations of olive oils

A novel screening method using an automated flow injection electrospray ionization tandem mass spectrometry system is proposed for the simultaneous determination of five nonprotein amino acids (β-alanine, alloisoleucine, ornithine, citrulline, pyroglutamic acid) and three betaines (glycine betaine, trigonelline, proline betaine) after derivatization with butanolic HCl. MS/MS experiments were carried out in a triple-quadrupole instrument using multiple reaction monitoring mode in <2 min. The proposed method provided high fingerprinting power to identify the presence of five of the studied compounds in different types of vegetable oils (soybean, sunflower, corn, olive) with LODs at parts per billion levels. The method was validated, and different mixtures of extra virgin olive oil with seed oils were analyzed, achieving the typification for the detection of adulterations in extra virgin olive oils up to 2% w/w. The nonprotein amino acid ornithine was confirmed as a marker for adulteration in the olive oils analyzed.

Comparison and analysis of fatty acids, sterols, and tocopherols in eight vegetable oils

The similarities and differences of eight vegetable oils produced in China were investigated in terms of their fatty acid, sterol, and tocopherol compositions and subsequent data processing by hierarchical clustering analysis and principal component analysis. The lipid profiles, acquired by analytical techniques tailored to each lipid class, revealed great similarities among the fatty acid profiles of corn and sesame oil as well as few differences in their sterol profiles. It turns out that not only was there great similarity between the fatty acid profiles of corn oil and sesame oil but also there were not too many differences for the sterol profiles. Sunflower and tea-seed oil showed similar sterol compositions, while the tea-seed oil tocopherol was very similar to palm oil. The results demonstrated that the use of only one of these profiles was unreliable for indentifying oil origin and authenticity. In contrast, the use of the sterol or tocopherol profile together with the fatty acid profile more accurately discriminates these oils.

Fast screening and secure confirmation of milk powder adulteration with maltodextrin via electrospray ionization-mass spectrometry [ESI(+)-MS] and selective enzymatic hydrolysis

Direct-infusion electrospray ionization-mass spectrometry [ESI(+)-MS] of several milk powder samples, confiscated by the Brazilian Federal Police, showed ions accounting for sodiated and potassiated molecules of disaccharides (m/z 365 and 381) as well as trisaccharides (m/z 527 and 543), whereas monosaccharide ions were not detected. The trisaccharide ions were not detected in samples of genuine milk powder, raising the suspicion that their presence indicates adulteration by the addition of maltodextrin. In control samples, maltose and maltotriose were hydrolyzed by alpha-glucosidase and not beta-galactosidase, whereas lactose was resistant to alpha-glucosidase but was hydrolyzed with beta-galactosidase. Samples suspected of being adulterated behaved in the same fashion, confirming the presence of maltose and maltotriose or maltodextrin. Direct-infusion ESI-MS is shown therefore to provide rapid screening of milk powder for adulteration with maltodextrin, whereas its combination with selective enzymatic hydrolysis provides highly reliable confirmation for unambiguous results.

Immunoaffinity capillary electrophoresis as a powerful strategy for the quantification of low-abundance biomarkers, drugs, and metabolites in biological matrices

In the last few years, there has been a greater appreciation by the scientific community of how separation science has contributed to the advancement of biomedical research. Despite past contributions in facilitating several biomedical breakthroughs, separation sciences still urgently need the development of improved methods for the separation and detection of biological and chemical substances. In particular, the challenging task of quantifying small molecules and biomolecules, found in low abundance in complex matrices (e.g., serum), is a particular area in need of new high-efficiency techniques. The tandem or on-line coupling of highly selective antibody capture agents with the high-resolving power of CE is being recognized as a powerful analytical tool for the enrichment and quantification of ultra-low abundance analytes in complex matrices. This development will have a significant impact on the identification and characterization of many putative biomarkers and on biomedical research in general. Immunoaffinity CE (IACE) technology is rapidly emerging as the most promising method for the analysis of low-abundance biomarkers; its power comes from a three-step procedure: (i) bioselective adsorption and (ii) subsequent recovery of compounds from an immobilized affinity ligand followed by (iii) separation of the enriched compounds. This technology is highly suited to automation and can be engineered to as a multiplex instrument capable of routinely performing hundreds of assays per day. Furthermore, a significant enhancement in sensitivity can be achieved for the purified and enriched affinity targeted analytes. Thus, a compound that exists in a complex biological matrix at a concentration far below its LOD is easily brought to well within its range of quantification. The present review summarizes several applications of IACE, as well as a chronological description of the improvements made in the fabrication of the analyte concentrator-microreactor device leading to the development of a multidimensional biomarker analyzer.

Detection of adulteration of poppy seed oil with sunflower oil based on volatiles and triacylglycerol composition

Although poppy seed oil is an expensive article of trade, no literature about identification methods for adulteration with cheaper vegetable oils, like sunflower oil, has been published. This kind of adulteration is a challenge for routine analytical methods, such as the determination of fatty acid composition, because of almost similar fatty acid ratios. The detection of adulteration of poppy seed oils with sunflower oils at different levels (5-40%, w/w) by using SPME-GC-MS and MALDI-ToF-MS is the subject of our investigation. With the mentioned SPME-GC-MS method, it was possible to detect an admixture of sunflower oils in all relevant (5-40%) amounts by using alpha-pinene as a marker compound. Admixture of sunflower oil with high levels of triolein (high-oleic acid type) could be undoubtedly detected by MALDI-MS down to the 5-10% level. In contrast, adulteration of pure poppy seed oil by "standard" sunflower oils remained indistinguishable using this MALDI-MS.