Sudan dyes in adulterated saffron (Crocus sativus L.): Identification and quantification by (1)H NMR

Determination of fifteen illegal colorants in traditional Chinese medicines by two hydrophobic DES-based microextraction methods coupled with an HPLC-DAD

The dyeing and adulteration of traditional Chinese medicines (TCMs) are continuously updated. Valuable analytical methods for the daily inspection of illegal colorant additives in TCMs and the preparations are in demand. Two deep eutectic solvent (DES)-based vortex-assisted liquid-liquid microextraction (VA-LLME) and ultrasonic-assisted solid-liquid microextraction (UA-SLME) were developed for the sample pretreatment of ten water-soluble colorants and five water-insoluble colorants, respectively, followed by an HPLC-DAD detection. Fifteen colorants were analyzed at four detection wavelengths within 40 min of gradient elution. The optimal DES of VA-LLME and UA-SLME were screened from 23 homemade DESs. The factors affecting the extraction efficiency of VA-LLME and UA-SLME were optimized systematically. Under the optimal conditions, ten water-soluble colorants analyzed by DES-based VA-LLME-HPLC-DAD showed good linearity (R ≥ 0.9995) within the optimal linear range. The LODs and LOQs were 0.2-1.0 μg g-1 and 0. 5-5.0 μg g-1, respectively. The recoveries of spiked samples were 80.2%-104.7 %, with RSDs ≤ 4.39 %. Five water-insoluble colorants of Sudan I‒IV and Sudan 7B analyzed by DES-based UA-SLME-HPLC-DAD showed good linearity (R ≥ 0.9995) within the optimal linear range. The LODs and LOQs were 0.8-8.0 μg g-1 and 4.0-40.0 μg g-1, respectively. The recoveries of spiked samples were 94.2%-103.1 %, with RSDs ≤ 4.81 %. The proposed DES-based VA-LLME-HPLC-DAD was successfully applied to analyze six water-soluble yellow colorants in Cuscutae Semen, salted Cuscutae Semen, and four water-soluble red colorants in Schisandrae Chinensis Fructus. The proposed DES-based UA-SLME-HPLC-DAD was successfully applied to analyze five water-insoluble red colorants in Dieda pills. The study provides analytical method options for routine tests of water-soluble, water-insoluble, or both water-soluble/-insoluble illegal colorant additives in herbal medical materials and preparations by the relevant proposed DES-based sample pretreatment method or a combination of the two proposed DES-based methods.

Reductions in spice lead levels in the republic of Georgia: 2020-2022

Spice adulteration using yellow lead chromate-based pigments has been documented as a growing global health concern. Spices from the Republic of Georgia with extremely high levels of lead, up to an order of magnitude higher than any other spices worldwide, have been implicated as sources of child lead poisoning. The objectives of this study were to 1) evaluate lead concentrations in spices sampled across the country of Georgia between 2020 and 2022, and 2) assess factors associated with spice adulteration, specifically the role of spice quality and regulatory enforcement. Spice samples were collected from 29 cities nationwide. The most populous cities were selected in each administrative region as well as those of importance to the spice supply chain. Sampling was carried out at the largest spice bazaars in each city. The regions of Adjara and Imereti were the focus of qualitative interviews conducted in 2021 with key businesspeople selling spices with very high and low levels of lead. The same cities and bazaars were visited at each of three sampling periods between 2020 and 2022. In total, 765 spice samples were collected. Lead concentrations in spices decreased over time, with a maximum of 14,233 μg/g in 2020 down to 36 μg/g in the final sampling round of 2022. A logistic regression determined that sampling round, region and spice type were associated with elevated lead in samples. Samples from Adjara and those containing marigold had the highest lead levels. Interviews with eighteen prominent spice vendors revealed difficulties sourcing sufficient quantities of high quality, brightly colored marigold, and concerns about adulteration. Interviews with two authorities from the National Food Authority highlighted the increased attention on regulating lead in spices since 2018. Continued monitoring and periodic regulatory enforcement may adequately disincentivize further adulteration with lead chromate in the spice industry in Georgia.

Heavy metals induced health risk assessment through consumption of selected commercially available spices in Noakhali district of Bangladesh

There are growing concerns for food safety due to the risks associated with heavy metal contamination of culinary herbs and spices in developing countries like Bangladesh. The objective of the present cross-sectional study is to determine the concentrations of the heavy metals Lead (Pb), Cadmium (Cd), Chromium (Cr), Copper (Cu), and Iron (Fe) in the branded and non-branded spices collected from the Noakhali district by Atomic absorption spectrophotometry method, as well as to assess the health hazard risk associated with heavy metals intake via consumption of spices. The findings revealed that the greatest concentrations of Pb (15.47 ± 1.93), Cd (1.65 ± 0.011), Cr (31.99 ± 3.97), Cu (18.84 ± 1.97), and Fe (9.29 ± 1.71) were found in Cardamom, Coriander leaf, Bay leaf, Dried chili, and Black pepper respectively. Around 37 % of Cr and 5 % of Fe Estimated Daily Intake (EDI) were greater than reference doses (RfD). All spices had Total Hazard Quotient (THQ) values for Pb, Cd, Cu, and Fe that were below acceptable, and 37 % of all spices had Total Target Hazard Quotient (TTHQ) values for Pb, Cd, Cu, and Fe that were over the standard range, suggesting adverse health impacts for consumers. Green chili, ginger, coriander leaf, and all kinds of chili powder and turmeric powder have been reported to have exceptionally high TTHQ levels of Cr. The estimated carcinogenic risk for chromium in non-branded coriander leaf was found to be higher than safe levels. This study provides valuable insights into the commonly consumed spices in Bangladesh and their potential health risks associated with heavy metal contamination. The findings of this study can be used by regulatory authorities to develop effective strategies and actions to mitigate these risks and safeguard public health.

Lead Poisoning From Home-Prepared Indian Spices in 3 Families

Spice consumption, along with other environmental factors, can contribute to pediatric lead poisoning. Although public health efforts have increased awareness of contamination of spices, false assumptions regarding the safety of home-prepared spices have emerged. Here, we present the clinical features, family beliefs, and environmental toxicology of 3 spice-associated pediatric lead poisoning cases.

Detection and Classification of Saffron Adulterants by Vis-Nir Imaging, Chemical Analysis, and Soft Computing

Saffron (Crocus sativus L.) is the most expensive spice in the world, known for its unique aroma and coloring in the food industry. Hence, its high price is frequently adulterated. In the current study, a variety of soft computing methods, including classifiers (i.e., RBF, MLP, KNN, SVM, SOM, and LVQ), were employed to classify four samples of fake saffron (dyed citrus blossom, safflower, dyed fibers, and mixed stigma with stamens) and three samples of genuine saffron (dried by different methods). RGB and spectral images (near-infrared and red bands) were captured from prepared samples for analysis. The amount of crocin, safranal, and picrocrocin were measured chemically to compare the images' analysis results. The comparison results of the classifiers indicated that KNN could classify RGB and NIR images of samples in the training phase with 100% accuracy. However, KNN's accuracy for different samples in the test phase was between 71.31% and 88.10%. The RBF neural network achieved the highest accuracy in training, test, and total phases. The accuracy of 99.52% and 94.74% was obtained using the features extracted from RGB and spectral images, respectively. So, soft computing models are helpful tools for detecting and classifying fake and genuine saffron based on RGB and spectral images.

Status of food colorants in India: conflicts and prospects

Food colorants are imperative ingredients for attracting consumers and in deciding their preferences. Here we discuss the current status of natural colorants and synthetic food colorants on the Indian market by appraising the growth of the food colorant market both globally and nationally, based on published case studies on synthetic food colorants (SFCs), rules, and regulations implemented by Food Safety and Standards Authority of India on natural food colorants and SFCs. The substantial lacunae in the research on the impacts of SFCs in the Indian population identified through our literature survey signify the scope and need for appraisal of the issues prevailing in the Indian food colorant market as well as the necessity of renewing the food colorant policies. The illegal use of banned food colorants, the adulteration of natural food colorants, mislabelling of SFCs as natural colorants, and the permitted use of internationally banned food colorants, as well as the unawareness among consumers are serious issues recognized. Appropriate labelling to denote natural food colorants' presence, renewed standards of policy to determine the permitted use of food colorants, comprehensive regulations for the production and use of natural food colorants, stringent rules to constrain the production of toxic SFCs are obligatory to breakdown the dilemma on the Indian food market. Most importantly, awareness and responsiveness should be generated among consumers regarding the illegal use and adulteration of colorants and the need to use natural colorants. We also recommend a logo to designate the presence of natural colorants which will aid the consumers to make the right choice.

Detection of Saffron’s Main Bioactive Compounds and Their Relationship with Commercial Quality

This review aims to evaluate the state of saffron’s main bioactive compounds and their relationship with its commercial quality. Saffron is the commercial name for the dried red stigmas of the Crocus sativus L. flower. It owes its sensory and functional properties mainly to the presence of its carotenoid derivatives, synthesized throughout flowering and also during the whole production process. These compounds include crocin, crocetin, picrocrocin, and safranal, which are bioactive metabolites. Saffron’s commercial value is determined according to the ISO/TS3632 standard that determines their main apocatotenoids. Other techniques such as chromatography (gas and liquid) are used to detect the apocarotenoids. This, together with the determination of spectral fingerprinting or chemo typing are essential for saffron identification. The determination of the specific chemical markers coupled with chemometric methods favors the discrimination of adulterated samples, possible plants, or adulterating compounds and even the concentrations at which these are obtained. Chemical characterization and concentration of various compounds could be affected by saffron’s geographical origin and harvest/postharvest characteristics. The large number of chemical compounds found in the by-products (flower parts) of saffron (catechin, quercetin, delphinidin, etc.) make it an interesting aromatic spice as a colorant, antioxidant, and source of phytochemicals, which can also bring additional economic value to the most expensive aromatic species in the world.

Recent progress in treatment of dyes wastewater using microbial-electro-Fenton technology

Globally, textile dyeing and manufacturing are one of the largest industrial units releasing huge amount of wastewater (WW) with refractory compounds such as dyes and pigments. Currently, wastewater treatment has been viewed as an industrial opportunity for rejuvenating fresh water resources and it is highly required in water stressed countries. This comprehensive review highlights an overall concept and in-depth knowledge on integrated, cost-effective cross-disciplinary solutions for domestic and industrial (textile dyes) WW and for harnessing renewable energy. This basic concept entails parallel or sequential modes of treating two chemically different WW i.e., domestic and industrial in the same system. In this case, contemporary advancement in MFC/MEC (METs) based systems towards Microbial-Electro-Fenton Technology (MEFT) revealed a substantial emerging scope and opportunity. Principally the said technology is based upon previously established anaerobic digestion and electro-chemical (photo/UV/Fenton) processes in the disciplines of microbial biotechnology and electro-chemistry. It holds an added advantage to all previously establish technologies in terms of treatment and energy efficiency, minimal toxicity and sludge waste, and environmental sustainable. This review typically described different dyes and their ultimate fate in environment and recently developed hierarchy of MEFS. It revealed detail mechanisms and degradation rate of dyes typically in cathodic Fenton system under batch and continuous modes of different MEF reactors. Moreover, it described cost-effectiveness of the said technology in terms of energy budget (production and consumption), and the limitations related to reactor fabrication cost and design for future upgradation to large scale application.

Non-Targeted NMR Method to Assess the Authenticity of Saffron and Trace the Agronomic Practices Applied for Its Production

The development of analytical methods aimed at tracing agri-food products and assessing their authenticity is essential to protect food commercial value and human health. An NMR-based non-targeted method is applied here to establish the authenticity of saffron samples. Specifically, 40 authentic saffron samples were compared with 18 samples intentionally adulterated by using turmeric and safflower at three different concentration levels, i.e., 5, 10, and 20 wt%. Statistical processing of NMR data furnished useful information about the main biomarkers contained in aqueous and dimethyl sulfoxide extracts, which are indicative of the presence of adulterants within the analyzed matrix. Furthermore, a discrimination model was developed capable of revealing the type of agronomic practice adopted during the production of this precious spice, distinguishing between organic and conventional cultivation. The main objective of this work was to provide the scientific community involved in the quality control of agri-food products with an analytical methodology able to extract useful information quickly and reliably for traceability and authenticity purposes. The proposed methodology turned out to be sensitive to minor variations in the metabolic composition of saffron that occur in the presence of the two adulterants studied. Both adulterants can be detected in aqueous extracts at a concentration of 5 wt%. A lower limit of detection was observed for safflower contained in organic extracts in which case the lowest detectable concentration was 20%.

Metal-Organic Frameworks-Based Sensors for Food Safety

Food contains a variety of poisonous and harmful substances that have an impact on human health. Therefore, food safety is a worldwide public concern. Food detection approaches must ensure the safety of food at every step of the food supply chain by monitoring and evaluating all hazards from every single step of food production. Therefore, early detection and determination of trace-level contaminants in food are one of the most crucial measures for ensuring food safety and safeguarding consumers’ health. In recent years, various methods have been introduced for food safety analysis, including classical methods and biomolecules-based sensing methods. However, most of these methods are laboratory-dependent, time-consuming, costly, and require well-trained technicians. To overcome such problems, developing rapid, simple, accurate, low-cost, and portable food sensing techniques is essential. Metal-organic frameworks (MOFs), a type of porous materials that present high porosity, abundant functional groups, and tunable physical and chemical properties, demonstrates promise in large-number applications. In this regard, MOF-based sensing techniques provide a novel approach in rapid and efficient sensing of pathogenic bacteria, heavy metals, food illegal additives, toxins, persistent organic pollutants (POPs), veterinary drugs, and pesticide residues. This review focused on the rapid screening of MOF-based sensors for food safety analysis. Challenges and future perspectives of MOF-based sensors were discussed. MOF-based sensing techniques would be useful tools for food safety evaluation owing to their portability, affordability, reliability, sensibility, and stability. The present review focused on research published up to 7 years ago. We believe that this work will help readers understand the effects of food hazard exposure, the effects on humans, and the use of MOFs in the detection and sensing of food hazards.

Highly Selective and Sensitive Benzimidazole Based Bifunctional Sensor for Targeting Inedible Azo Dyes in Red Chilli, Red Food Color, Turmeric Powder, and Cu(Ii) in Coconut Water

In this study, a simple Benzimidazole based bifunctional chemosensor 4-(2-(3,4-dimethoxyphenyl)-1H-benzo[d]imidazol-6-yl) benzene-1,2-diamine, L was synthesized and characterized. The sensor proved to be selective and sensitive towards detecting banned azo dyes Sudan Dye I, II, and Metanil Yellow via fluorescence turn-off response. The proposed mechanism of fluorescence quenching was the inner filter effect. LODs for Sudan I, II, and Metanil Yellow were found to be 0.009 µM, 0.012 µM, and 0.0073 µM, respectively. The developed chemosensor also showed a colorimetric response towards Cu (II) ions via an apparent color change from yellow to pink. LOD for Cu (II) ions was found to be 1.2 µM. The synthesized benzimidazole based bifunctional chemosensor was adequately tested to determine Sudan I in Red chili powder and red Food color samples, Metanil yellow in turmeric powder, and Cu(II) packaged coconut water.

Detection-confirmation-standardization-quantification: a novel method for the quantitative analysis of active components in traditional Chinese medicines

Background

Quantitative analysis of the active ingredients of Traditional Chinese Medicine is a research tendency. The objective of this study was to build a novel method, namely, Detection-confirmation-standardization-quantification (DCSQ), for the quantitative analysis of active components in traditional Chinese medicines, without individual reference standard.

Methods

Danshen (the dried root of Radix Salvia miltiorrhiza) was used as the matrix. The “extraction” function in high-performance liquid chromatography-mass (HPLC-MS) instrument was used to find the peaks corresponding to cryptotanshinone, tanshinone I, and tanshinone IIA in the total ion current (TIC) chromatogram of Danshen. The multicomponent reference standard (MCRS) containing the three tanshinones mainly was prepared by preparative HPLC. The contents of them in the resulting MCRS were determined by NMR; moreover, the constituents of the MCRS were confirmed. The MCRS containing known content of the three tanshinones was used as the reference standard for the quantitative analysis of cryptotanshinone, tanshinone I and tanshinone IIA in Danshen Samples by analytical HPLC.

Results

The optimized HPLC conditions for the quantitative analysis of the active components in Danshen were established, and the assignments of the extracted peaks were confirmed by analyzing the characteristic fragments in their MS/MS product ion spectra and UV spectra. Then, the MCRS containing the three tanshinones were successfully prepared. The results of determination about the contents by NMR showed linearity fitted with high likelihood and calibration curves possessed high linearity. The results of determination on Danshen Samples obtained through DCSQ exhibited minimal deviations, in contrast to those obtained through individual reference standards.

Conclusion

The establishing DCSQ is independent and convenient for the quantitative analysis of the active components in TCMs by MCRS, without individual reference standard. This method is a great advance in quantitative analysis for complex composition, especially TCMs.

External parameter orthogonalization-support vector machine for processing of attenuated total reflectance-mid-infrared spectra: A solution for saffron authenticity problem

In the present work, a new approach based on external parameter orthogonalization combined with support vector machine (EPO-SVM) is proposed for processing of attenuated total reflectance-Fourier transform mid-infrared (ATR-FT-MIR) spectra with the goal of solving authentication problem in saffron, the most expensive spice in the world. First, one-hundred authentic saffron samples are clustered by principal component analysis (PCA) with EPO as the best preprocessing strategy. Then, EPO-SVM is used for the detection of four commonly used plant-derived adulterants (i.e. safflower, calendula, rubia, and style) in binary mixtures (saffron and each of plant adulterants) and its performance is compared with other common classification methods. The obtained results showed that the EPO-SVM approach has a much better classification accuracy (>95%) than other methods (accuracy<89.2%). Finally, two different sample sets including mixture of saffron and four plant adulterants and commercial saffron samples are used for validation of the developed EPO-SVM model. In this regard, classification figures of merit in terms of sensitivity, specificity and accuracy were respectively 96.6%, 97.1%, and 96.8% which showed good classification performance. It is concluded that the proposed EPO-PCA and EPO-SVM approaches can be considered as reliable tools for authentication and adulteration detection in saffron samples.

A review on the application of spectroscopy to the condiments detection: from safety to authenticity

Condiments are the magical ingredients that make the food present a richer taste. In recent years, due to the increasing consciousness of food safety and human health, much progress has been made in developing rapid and nondestructive techniques for the evaluation of food condiments safety, authentication, and traceability. The potential of spectroscopy techniques, such as near-infrared (NIR), mid-infrared (MIR), Raman, fluorescence, inductively coupled plasma (ICP), and hyperspectral imaging techniques, has been widely enhanced by numerous applications in this field because of their advantages over other analytical techniques. Following a brief introduction of condiment and safety basics, this review mainly focuses on recent vibrational and atomic spectral applications for condiment nondestructive analysis and evaluation, including (1) chemical hazards detection; (2) microbiological hazards detection; and (3) authenticity concerns. The review shows current spectroscopies to be effective tools that will play indispensable roles for food condiment evaluation. In addition, online/real-time applications of these techniques promise to be a huge growth field in the near future.

DNA barcoding: a modern age tool for detection of adulteration in food

Globalization of the food trade requires precise and exact information about the origin, methods of production, transformation technologies, authentication, and the traceability of foodstuffs. New challenges in food supply chains such as deliberate fraudulent substitution, tampering or mislabeling of food and its ingredients or food packaging incapacitates the market and eventually the national economy. Currently, no proper standards have been established for the authentication of most of the food materials. However, in order to control food fraud, various robust and cost-effective technologies have been employed, like a spectrophotometer, GC-MS, HPLC, and DNA barcoding. Among these techniques, DNA barcoding is a biotechnology advantage with the principle of using 400-800 bp long standardized unique DNA sequences of mitochondrial (e.g. COI) or plastidial (e.g. rbcL) of nuclear origin (e.g. ITS) to analyze and classify the food commodities. This review covers several traded food commodities like legumes, seafood, oils, herbal products, spices, fruits, cereals, meat, and their unique barcodes which are critically analyzed to detect adulteration or fraud. DNA barcoding is a global initiative and it is being accepted as a global standard/marker for species identification or authentication. The research laboratories and industries should collaborate to realize its potential in setting standards for quality assurance, quality control, and food safety for different food products.

A critical review on advances in the practices and perspectives for the treatment of dye industry wastewater

Rapid industrialization has provided comforts to mankind but has also impacted the environment harmfully. There has been severe increase in the pollution due to several industries, in particular due to dye industry, which generate huge quantities of wastewater containing hazardous chemicals. Although tremendous developments have taken place for the treatment and management of such wastewater through chemical or biological processes, there is an emerging shift in the approach, with focus shifting on resource recovery from such wastewater and also their management in sustainable manner. This review article aims to present and discuss the most advanced and state-of-art technical and scientific developments about the treatment of dye industry wastewater, which include advanced oxidation process, membrane filtration technique, microbial technologies, bio-electrochemical degradation, photocatalytic degradation, etc. Among these technologies, microbial degradation seems highly promising for resource recovery and sustainability and has been discussed in detail as a promising approach. This paper also covers the challenges and future perspectives in this field.

Turmeric means "yellow" in Bengali: Lead chromate pigments added to turmeric threaten public health across Bangladesh

Adulteration is a growing food safety concern worldwide. Previous studies have implicated turmeric as a source of lead (Pb) exposure due to the addition of lead chromate (PbCrO₄), a yellow pigment used to enhance brightness. We aimed to assess the practice of adding yellow pigments to turmeric and producer- consumer- and regulatory-factors affecting this practice across the supply chain in Bangladesh. We identified and visited the nine major turmeric-producing districts of Bangladesh as well as two districts with minimal turmeric production. In each district, we conducted semi-structured interviews and informal observations with individuals involved in the production, consumption, and regulation of turmeric. We explored perceptions of and preferences for turmeric quality. We collected samples of yellow pigments and turmeric from the most-frequented wholesale and retail markets. We collected samples of turmeric, pigments, dust, and soil from turmeric polishing mills to assess evidence of adulteration. Interviews were analyzed through an inductive, thematic coding process, with attention focused on perceptions of and preferences for turmeric quality. Samples were analyzed for Pb and chromium (Cr) concentrations via inductively coupled plasma mass spectrometry and x-ray fluorescence. In total, we interviewed 152 individuals from across the supply chain and collected 524 samples of turmeric, pigments, dust, and soil (Table S3, Table S4). Turmeric Pb and Cr concentrations were highest in Dhaka and Munshiganj districts, with maximum turmeric powder Pb concentrations of 1152 μg/g, compared to 690 μg/g in the 9 major turmeric-producing districts. We found evidence of PbCrO₄-based yellow pigment adulteration in 7 of the 9 major turmeric-producing districts. Soil samples from polishing mills contained a maximum of 4257 μg/g Pb and yellow pigments contained 2-10% Pb by weight with an average Pb:Cr molar ratio of 1.3. Turmeric wholesalers reported that the practice of adding yellow pigments to dried turmeric root during polishing began more than 30 years ago and continues today, primarily driven by consumer preferences for colorful yellow curries. Farmers stated that merchants are able to sell otherwise poor-quality roots and increase their profits by asking polishers to adulterate with yellow pigments. Adulterating turmeric with lead chromate poses significant risks to human health and development. The results from this study indicate that PbCrO₄ is being added to turmeric by polishers, who are unaware of its neurotoxic effects, in order to satisfy wholesalers who are driven by consumer demand for yellow roots. We recommend immediate intervention that engages turmeric producers and consumers to address this public health crisis and ensure a future with Pb-free turmeric.

The potentiality of NMR-based metabolomics in food science and food authentication assessment

In the last years, there was an increasing interest on nuclear magnetic resonance (NMR) spectroscopy, whose applications experienced an exponential growth in several research fields, particularly in food science. NMR was initially developed as the elective technique for structure elucidation of single molecules and nowadays is playing a dominant role in complex mixtures investigations. In the era of the "omics" techniques, NMR was rapidly enrolled as one of the most powerful methods to approach metabolomics studies. Its use in analytical routines, characterized by rapid and reproducible measurements, would provide the identification of a wide range of chemical compounds simultaneously, disclosing sophisticated frauds or addressing the geographical origin, as well as revealing potential markers for other authentication purposes. The great economic value of high-quality or guaranteed foods demands highly detailed characterization to protect both consumers and producers from frauds. The present scenario suggests metabolomics as the privileged approach of modern analytical studies for the next decades. The large potentiality of high-resolution NMR techniques is here presented through specific applications and using different approaches focused on the authentication process of some foods, like tomato paste, saffron, honey, roasted coffee, and balsamic and traditional balsamic vinegar of Modena, with a particular focus on geographical origin characterization, ageing determination, and fraud detection.

Voltammetric Determination of Sudan 1 in Food Samples Using Its Cu(II) Compound

In this work, we developed a sensitive, simple and convenient electrochemical method to determine Sudan 1 in food samples using its Cu(II) coordination compound. Using phosphate buffer solution at pH=5.0 as supporting electrolyte (75% methanol), differential pulse voltammetry and 6-fold concentration of Cu(II), the electrochemical oxidation signal of Sudan 1–Cu(II) coordination compound at glassy carbon electrode significantly increased when compared to the one without the added Cu(II). The experimental conditions such as the amount of methanol, pH, the concentration of Cu(II) and the instrumental parameter were optimized for the determination of Sudan 1. Under the optimal experimental conditions, the oxidation peak current of Sudan 1 was proportional to its concentration in two ranges: 0.04–0.09 to 0.09–5.3 µM with a detection limit of 0.71 nM (S/N=3). The interference effects of Sudan 2-4 with the determination of Sudan 1 was also evaluated. The developed method was successfully applied to tomato, chilli sauces, ketchup and chilli powder. The analysis results of Sudan 1 in food samples obtained by the proposed method were in a good agreement with the reference values detected by HPLC.

Nuclear Magnetic Resonance (NMR) Spectroscopy in Food Science: A Comprehensive Review

Nuclear magnetic resonance (NMR) spectroscopy is a robust method, which can rapidly analyze mixtures at the molecular level without requiring separation and/or purification steps, making it ideal for applications in food science. Despite its increasing popularity among food scientists, NMR is still an underutilized methodology in this area, mainly due to its high cost, relatively low sensitivity, and the lack of NMR expertise by many food scientists. The aim of this review is to help bridge the knowledge gap that may exist when attempting to apply NMR methodologies to the field of food science. We begin by covering the basic principles required to apply NMR to the study of foods and nutrients. A description of the discipline of chemometrics is provided, as the combination of NMR with multivariate statistical analysis is a powerful approach for addressing modern challenges in food science. Furthermore, a comprehensive overview of recent and key applications in the areas of compositional analysis, food authentication, quality control, and human nutrition is provided. In addition to standard NMR techniques, more sophisticated NMR applications are also presented, although limitations, gaps, and potentials are discussed. We hope this review will help scientists gain some of the knowledge required to apply the powerful methodology of NMR to the rich and diverse field of food science.

Integrated analytical assets aid botanical authenticity and adulteration management

This article reviews and develops a perspective for the meaning of authenticity in the context of quality assessment of botanical materials and the challenges associated with discerning adulterations vs. contaminations vs. impurities. Authentic botanicals are by definition non-adulterated, a mutually exclusive relationship that is confirmed through the application of a multilayered set of analytical methods designed to validate the (chemo)taxonomic identity of a botanical and certify that it is devoid of any adulteration. In practice, the ever-increasing sophistication in the process of intentional adulteration, as well as the growing number of botanicals entering the market, altogether necessitate a constant adaptation and reinforcement of authentication methods with new approaches, especially new technologies. This article summarizes the set of analytical methods - classical and contemporary - that can be employed in the authentication of botanicals. Particular emphasis is placed on the application of untargeted metabolomics and chemometrics. An NMR-based untargeted metabolomic model is proposed as a rapid, systematic, and complementary screening for the discrimination of authentic vs. potentially adulterated botanicals. Such analytical model can help advance the evaluation of botanical integrity in natural product research.

A feasible and practical 1H NMR analytical method for the quality control and quantification of bioactive principles in Lycii Fructus

Lycii Fructus, a solanaceous drug, is widely used as functional foods and in Traditional Chinese Medicine. Samples collected from different regions of China have been found to be not identical in chemical compositions which might affect the biological activities. Although many chromatographic and spectrometric methods have been reported to determine the concentration of betaine and other bioactive amino acids, disturbance resulted from other polar substances with low UV-absorbance and expensive mass facilities reduced the applicability of these techniques. In the present study, the strong cation exchange solid phase extraction procedure incorporated with ¹H NMR was successfully developed as a rapid and reliable method that can simultaneously determine betaine, citric acid, threonine, alanine, and proline in various Lycii Fructus. In addition, ERETIC 2 method based on PULCON principle was also applied and compared with conventional method. This feasible and practical method offers a very powerful tool for the quality control of commercial Lycii Fructus from different sources.