Surface enhanced Raman spectroscopy (SERS): A novel reliable technique for rapid detection of common harmful chemical residues

BackgroundThe irrational usage of chemical substances including pesticides and drugs in agricultural and food production is a significant food safety issue due to its residues. Therefore, the detection of harmful residues in foods is an indispensable step for guaranteeing the consumer's health. Conventional methods, such as HPLC, GC-MS and LC-MS are accurate enough, but they fail to meet the requirements of the modern industry for rapid and on-line detection. Novel reliable techniques should thus be developed as alternatives.Scope and approachIn this review, fundamentals of surface-enhanced Raman spectroscopy (SERS) is introduced. Recent advances in its usage for detecting harmful chemical residues in agricultural products including pesticides, antibiotics and β₂-adrenergic agonists are discussed by two typical ways of detection improvement, and the advantages of SERS are addressed. Finally, future trends to routine use of SERS applications in harmful residues are presented.Key findings and conclusionsSERS is a promising detection technique for the detection of common harmful chemical residues with merits of simple sampling, rapid data collection and non-destructiveness. Despite rapid developments in the technology, there is much studies should be done before SERS could be used as a daily tool for the industry.     

An LC–ESI–MS/MS method for residues of fluoroquinolones,sulfonamides, tetracyclines and trimethoprim in feedingstuffs: validation and surveillance

ABSTRACT

An increasing concern about food safety has been observed over the years. The presence of drugs residues in food is one of the major subjects of research in food safety. Feedingstuffs can be responsible for carryover into the food chain of residues of several drugs. This paper describes the development, validation and application of a fast and simple method for analysis of 24 antibiotic residues in feedingstuffs for cattle, pigs and poultry. Analytes include compounds from different antimicrobials classes, such as sulfonamides (sulfadiazine, sulfamethazine, sulfamethoxazole, sulfaquinoxaline, sulfachlorpyridazine, sulfadoxine, sulfadimethoxine, sulfizoxazole, sulfamerazine and sulfathiazole), fluoroquinolones (ciprofloxacin, enrofloxacin, norfloxacin, danofloxacin, difloxacin, sarafloxacin, flumequine, nalidixic acid and oxolinic acid), tetracyclines (tetracycline, doxycycline, oxytetracycline and chlortetracycline) and trimethoprim. Samples were extracted with methanol:water (70:30) 0.1% formic acid, followed by clean-up steps using centrifugation, low-temperature purification (LTP) and ultracentrifugation. Instrumental analysis was performed using liquid chromatography coupled to tandem mass spectrometry. Chromatographic separation was achieved using a C18 column and a mobile phase composed of acetonitrile and water, both with 0.1% formic acid. Validation parameters such as limit of detection (LOD), limit of quantification (LOQ), selectivity, linearity, accuracy, precision, decision limit (CCα) and detection capability (CCβ) were determined and meet the adopted criteria. LOD and LOQ were set to 30 and 75 µg kg^?1, respectively. Inter-day precision were in the range from 4.0 to 11.1%, and linearity provides values of r² above 0.95 for all analytes. The optimised method was applied to the analysis of more than 1500 real samples within the period 2012–2017. Non-compliant results were discussed and classified in terms of analytes, feed types and target species. Multivariate analysis of the data was performed using principal component analysis.     

Residues of antibacterial drugs in honey from the Italian market

Antibacterial drugs are used worldwide for the control of American and, less often, European foulbrood. Their administration is mostly uncontrolled and applied without approved protocols and instructions for use as well as precautionary recommendations. Consequently, this practice is responsible for the contamination of beehive products and contributes to the problem of food safety. According to this situation, 4672 analyses were carried out on 5303 honeys collected from 2001 to 2007. These samples were investigated for antibacterial residues of tetracyclines, sulphonamides, streptomycin, chloramphenicol and tylosin. Honeys were classified according to their origin: imported honey and honey from the Italian market. In the last group (only for samples collected from 2001 to 2004), another type of honey was distinguished: that of local honey. A total of 6.3% of all samples were positive for the antibacterial drugs analysed; in particular, 6.8% of imported honeys and 6.1% of honeys on the Italian market. Only 1.7% of local honey had antibacterial residues. These results are indicative of a rather frequent presence of antibacterial drug residues in both Italian and imported honeys. Furthermore, the data showed that among the active substances analysed, sulphonamides are the most used antibacterial substance followed by tetracyclines, streptomycin, tylosin, and chloramphenicol. Finally, a continuous monitoring programme is needed, accompanied by an education programme to beekeepers on proper hive management.     

Characterization,antigenicity and detection of fish gelatine and isinglass used as processing aids in wines

Fish gelatine (FG) and isinglass (IG) are widely used in the pharmaceutical industry and as ingredients or processing aids in food production. Both products are the focus of interest since several countries, particularly the member states of the EU and Japan, USA, Australia and New Zealand, have introduced special labelling regulations for allergenic foodstuffs, such as fish and products thereof. Thus, there is a demand for a reliable and sensitive method for the detection of FG and IG in foodstuffs. In this study, the characterization of various FGs and IGs, polyclonal antibodies raised against fish collagen and the development of a sensitive indirect ELISA for the detection of FG and IG is described. The ELISA method detected ≤0.11 µg ml^?1 from all FGs and IGs tested. The indirect ELISA was applied to various experimental wines where FG and IG had been used as processing aids and to several commercial wines. No residues of FG and IG were detected in the experimental wines additionally treated with bentonite, a strong adsorbent for proteins, and successive filtration. Additionally, no residues were found in the commercial wines. However, amounts of up to 0.33 µg ml^?1 were found in some experimental wines not treated with bentonite and successive filtration. Therefore, wines may contain traces of FG and IG that were used as processing aids during wine production. However, treatment with bentonite in combination with additional filtration had a clear impact on these residues.     

Quantitative analysis of Sudan dye adulteration in paprika powder using FTIR spectroscopy

ABSTRACT

As adulteration of foodstuffs with Sudan dye, especially paprika- and chilli-containing products, has been reported with some frequency, this issue has become one focal point for addressing food safety. FTIR spectroscopy has been used extensively as an analytical method for quality control and safety determination for food products. Thus, the use of FTIR spectroscopy for rapid determination of Sudan dye in paprika powder was investigated in this study. A net analyte signal (NAS)-based methodology, named HLA/GO (hybrid linear analysis in the literature), was applied to FTIR spectral data to predict Sudan dye concentration. The calibration and validation sets were designed to evaluate the performance of the multivariate method. The obtained results had a high determination coefficient (R²) of 0.98 and low root mean square error (RMSE) of 0.026% for the calibration set, and an R² of 0.97 and RMSE of 0.05% for the validation set. The model was further validated using a second validation set and through the figures of merit, such as sensitivity, selectivity, and limits of detection and quantification. The proposed technique of FTIR combined with HLA/GO is rapid, simple and low cost, making this approach advantageous when compared with the main alternative methods based on liquid chromatography (LC) techniques.     

RESIDUES – A FOOD SAFETY PROBLEM?

Considerable time, regulation and consumer concern is associated with the question of chemical residues in food. Potential residues in food span a broad range from natural contaminants (mycotoxins) through environmental contaminants (dioxins, PCBs), agrochemicals (nitrates, pesticides), veterinary drugs (anthelmintics, antibiotics), prohibited substances (hormonal growth promoters), chemicals arising in processing (nitrosamines), packaging components (plasticisers) to contaminants arising in domestic food preparation (heavy metals). The occurrence or avoidance of these chemicals as residues in food is to a greater or lesser extent under the control of the food producer, processor and consumer in the activities of growing/producing, treating, storing, processing, packaging and cooking. The fundamental question is to what extent do or can residues in food constitute a food safety hazard for the consumer. Many of these substances are regulated as to their use and as to their acceptable levels in food while others, by their nature, arise as more random occurrences and, as such, are less prone to regulation. Of particular concern to the producer, processor and retailer of food is what steps may be taken to ensure that the food supply is safe. Best practice in plant and animal husbandry by the producer, in sourcing of material and in control of food manufacturing by the processor, and in sourcing of food products by the retailer combine to assure the safety of food to the consumer. This paper describes the various classes of chemicals which can arise as residues in food, particularly agrochemicals and veterinary drugs, the usage patterns which decrease/increase the likelihood of the occurrence of residues at unacceptable levels, how and in what form(s) residues can occur in foods, and the contribution of food processing to a reduction or otherwise of residue levels in food consumed. Consideration will be given, also, to quantifying the risk posed by chemical residues in food and to a study of the results from a Residue Database and from residue monitoring/surveillance as an indicator of risk to the consumer.     

Existing and potential applications of ultraviolet light in the food industry – a critical review

Short‐wave ultraviolet light (UVC, 254 nm) can reduce dramatically the microbial load in air or on hard surfaces free from food residues, and can eliminate pathogens from potable water filtered to remove organic residues and ‘clumps’ of bacteria. More recently, approval of the Food and Drug Administration (USA) has been sought for a system for the destruction of pathogenic bacteria in fruit juices using UVC, and the same approach could perhaps be applied to remove spoilage organisms from cider or wines. In contrast, long‐wave UV light (UVA, >320 nm) has limited microbiocidal properties, and for practical applications its effectiveness has to be enhanced by the presence of photosensitive compounds (eg furocoumarins) that will diffuse into a microbial cell prior to irradiation. The penetration of UVA into water is better than that of UVC, and its bacteriocidal action in the presence of photosensitisers can be rapid. However, pure furocoumarins are expensive and their addition to foodstuffs might be questioned on safety grounds. © 2000 Society of Chemical Industry     

Effect of protein glycation in the presence or absence of wheat proteins on detection of soybean proteins by commercial ELISA

Soybean (Glycine max) is the world's primary provider of protein and oil and is widely used in foodstuffs. However, the use of soybean in foodstuffs might pose a serious threat to allergic consumers since some proteins can cause allergic reactions. To date mostly ELISA methods are used for testing contamination of foodstuffs with soybean. In view of the complexity regarding allergen detection in foodstuffs and appropriate food product labelling, the aim of this study was to investigate the impact of the Maillard reaction on the detectability of soybean proteins using commercial ELISA kits. Accumulation of protein-bound carbonyls, modification of reactive lysine residues and severe aggregation as a result of incubation with glucose, in the presence or absence of soluble wheat proteins, were recorded. Moreover, detection of soybean proteins by means of three commercial ELISA kits was strongly altered and was highly dependent on the type of kit used.     

Ozone in the food industry: Principles of ozone treatment,mechanisms of action,and applications: An overview

ABSTRACT

The food contamination issue requires continuous control of food at each step of the production process. High quality and safety of products are equally important factors in the food industry. They may be achieved with several, more or less technologically advanced methodologies. In this work, we review the role, contribution, importance, and impact of ozone as a decontaminating agent used to control and eliminate the presence of microorganisms in food products as well as to extend their shelf-life and remove undesirable odors. Several researchers have been focusing on the ozone's properties and applications, proving that ozone treatment technology can be applied to all types of foods, from fruits, vegetables, spices, meat, and seafood products to beverages. A compilation of those works, presented in this review, can be a useful tool for establishing appropriate ozone treatment conditions, and factors affecting the improved quality and safety of food products. A critical evaluation of the advantages and disadvantages of ozone in the context of its application in the food industry is presented as well.     

Non-targeted screening of pesticides for food analysis using liquid chromatography high-resolution mass spectrometry-a review

ABSTRACT

Targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a robust and reliable tool in quantitative analysis of pesticide residues in food samples. However, these methods have been only targeted to a predefined set of pesticides. Many other unexpected pesticides and/or their (bio)transformation products present in food matrices that may be harmful to consumers need to be discovered for food safety monitoring purpose. Therefore, non-targeted screening approaches using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) have gained much attention in food monitoring recently. However, the development and implementation of non-targeted screening of potential pesticides and their (bio)transformation products in food samples are particularly challenging due to the inherent sample complexity and large quantity of MS data. To provide guidance on how to use non-targeted screening approaches for pesticide screening, three different aspects, namely, sample preparation, data acquisition and data processing, encompassed in the workflow of non-targeted screening approaches have been discussed, and current strategies, advances and challenges regarding these three aspects are reviewed. In addition, the recent application of non-targeted screening analysis of pesticide residues and their (bio)transformation products in food samples has been overviewed in this paper.     

Gold nanoparticles: From synthesis,properties to their potential application as colorimetric sensors in food safety screening

BackgroundFood safety management and guarantee are the basic requirement during food processing, circulation, storage, and marketing. Elevating the ability to evaluate food quality and safety in a rapid, sensitive and reliable manner is of great importance in food industry. Recently, gold nanoparticles due to unique optical property, ease of functionalization and preparation, and high selectivity and sensitivity have received considerable attention in the field of food safety.Scope and approachGold nanoparticles exhibit distinguishable optical characteristic in different aggregated states and thus have been developed into simple colorimetric sensors for the quick detection of chemical contaminants in food samples. Herein, we reviewed the current methods for synthesis and functionalization of gold nanoparticles, strategies for fabrication of gold nanoparticle based colorimetric sensors and their applications in rapid analysis of food contaminant. Moreover, the inherent optical property of gold nanoparticles and their detecting principle have been highlighted. Finally, the main challenges and future efforts in developing such colorimetric sensors for food contaminants detection were discussed.Key findings and conclusionsGold nanoparticles as smart colorimetric sensors conform to the requirement of modern analysis, such as high selectivity, sensitivity, simplicity, celerity, and portability. Thus, they have great potential to be applied as power sensing tools for food safety screening.     

Crosslinking in polysaccharide and protein films and coatings for food contact – A review

BackgroundCrosslinking is the process of forming tridimensional networks by linking polymer chains by covalent or noncovalent bonds. It is useful for polysaccharide- and protein-based films and coatings to be applied to food surfaces, enhancing their water resistance as well as mechanical and barrier properties. Crosslinkers intended to be used for food contact materials must present low toxicity.Scope and approachThis review is a summary of the main crosslinking agents which have been used for protein and polysaccharide films and coatings, and which may be applied as food contact materials. The study emphasizes the mechanisms of crosslinking agents, the chemical groups involved, conditions for application, advantages and drawbacks, as well as examples of applications for food contact materials.Key findings and conclusionsCrosslinking is a promising technique to improve the performance and applicability of protein- and polysaccharide-based food contact materials, especially concerning their water sensitivity, which hinders many of their potential applications as food contact materials. Some aldehydes are very effective as crosslinkers, but they have been avoided in food contact materials because of possible migration of aldehyde residues to food, and less toxic compounds have been studied for those applications, such as phenolic acids, oxidized polysaccharides, and enzymes. Crosslinking techniques may help make protein- and polysaccharide-based materials more suitable for large-scale processing and applications in the future.     

Antimicrobial residues in the food chain

Antimicrobials are used in the food chain. It is often not appreciated that the requirements for a sponsor of a veterinary antimicrobial drug intended for use in food-producing animals are more onerous than those for companion animals or indeed for man. This is primarily because of the issue of potential drug residues being ingested in the human diet. Indeed this is the rationale behind the Harmonised VICH Guideline 36. It is argued that this current trilateral (EU-Japan-USA) scientific guidance is appropriate to determine the safety of antimicrobial residues in the food chain; much of this thinking has been developed from previous considerations of these matters. In this contribution we will discuss this approach, which addresses the complexity of the human intestinal flora and reduces uncertainty when determining microbiological acceptable daily intakes, and make some concluding remarks with respect to food safety and security with respect to the use of antimicrobials. A variety of toxicological evaluations are performed to establish the safety of veterinary drug residues in human food and as part of such evaluation for veterinary antimicrobial drugs is the safety of their residues on the human intestinal flora; this is an important step in ensuring the safety of the food supply.     

Early detection of food pathogens and food spoilage microorganisms: Application of metabolomics

BackgroundFood safety is a major issue, with a large number of people around the world suffering from illness due to the consumption of contaminated and unsafe food products. An early detection of food pathogens and spoilage microorganisms is an important step that can help to control a foodborne outbreak, thus avoiding the loss of a massive amount of food products.Scope and approachMetabolomics is generally a hypothesis generating tool that makes use of different analytical instruments to analyse as many metabolites as possible in a given biological sample. Metabolomics has already been successfully applied to different areas of food science. Here, I present metabolomics as a valuable tool for studying the metabolism of food pathogens and spoilage microorganisms.Key findings and conclusionsThe scientific area of metabolomics has improved tremendously over last decade. Due to the rapid development of instrumental platforms, it is now possible to analyse a wide range of metabolites present in food and produced by microorganisms. This approach has a high potential to determine biomarkers which can later be used for the development of early detection tools for food pathogens and spoilage microorganisms, thus ensuring a better management of food safety.     

食品安全综合评价指标体系构建与应用

目的：构建一套规范的食品安全综合评价指标体系。方法：从理论研究和实践探索两个层面梳理了国内外食品安全综合评价指标体系研究现状。结果：基于层次分析法和德尔菲法构建了一套涵盖6个准则、24项一级指标、41项二级指标的食品安全综合评价指标体系;应用该套指标结合相关统计数据对天津市各行政区食品安全状况开展实证分析。结论：该套指标能够有效评价各区食品安全状况,具备综合性、实操性、可比性等优势。     

An overview of solid‐phase extraction of food flavor compounds and chemical residues

Abstract

Solid‐phase extraction (SPE) is a rapid and sensitive sample preparation technique whose use has increased considerably within the last decade. This emerging technology has successfully replaced many tedious conventional methods of isolation and extraction of various chemicals in food, environmental, pharmaceutical, and biological samples. Sample preparation and concentration via SPE can be achieved in a one‐step extraction, and the methodology is appropriate for isolating trace amounts of chemical compounds from complex matrices. This paper gives an overview on the use of SPE as a sample preparation tool for the isolation of flavor compounds and chemical residues in food. Applying SPE in the areas of food science and agriculture will be valuable in assuring the safety and quality of our food products.     

A compendium of wheat germ: Separation,stabilization and food applications

BackgroundWheat germ is a precious by-product deriving from the milling industry, as it is a natural concentrated source of essential amino and fatty acids, minerals, vitamins, tocopherols, and phytosterols. However, the presence of high enzymatic activities together with a high content of unsaturated oil, induce a fast decrease in the nutritional value of wheat germ during storage and, consequently, strongly limit product's shelf-life.Scope and approachIn recent decades, flour blends from raw or/and processed wheat germ received great interest from nutritional and technological perspectives. Nevertheless, the quality of the end-product strongly depended on the supplementation level, as well as the type and the severity of separation and stabilization techniques that wheat germ went through. Hence, in this review, the newest advances in wheat germ pre-handling approaches and food applications are discussed to provide relevant and updated information about its worthiness to be a part of the human diet.Key findings and conclusionsTo fully valorize and preserve the nutritious potential of wheat germ, effective pre-treatments of separation and stabilization are needed to guarantee its stability and suitability to meet food quality and safety standards. Such an underutilized ingredient might be a valuable fortifying component for a spectrum of foodstuffs.     

食品中氨基糖苷类残留检测技术难点及解决对策研究进展

氨基糖苷类药物为当前畜禽养殖业常用的药物,不规范使用会导致药物在畜禽肉及其副产品中的残留,为目前食品安全重要问题之一。因此,监测食品中氨基糖苷类的残留对于保障食品安全和人类的健康具有重要的意义。但由于氨基糖苷类药物结构和化学性质的特殊性,给检验检测带来了一定的技术难度。本文针对目前食品中氨基糖苷类残留检测的的技术难点和解决对策进行了阐述,并对今后在解决检测技术难点的方向进行了展望,以期为食品中氨基糖苷类残留检测方法的开发研究提供借鉴和依据。     

Optimization of the GC method for routine analysis of the fatty acid profile in several food samples

The fatty acids profile of food samples was determined by gas chromatography (GC). The fat was extracted from different food samples using Soxhlet technique. Extracted triglycerides were converted to corresponding methyl esters using methanolic solution of potassium hydroxide (trans-esterification). GC method for the analysis of obtained methyl esters was optimized on two different cyanopropyl capillary columns. Good resolution of all fatty acids commonly found in foodstuffs was achieved. After optimization, the method was validated and the results for linearity, precision, limit of quantitation (LOQ), limit of detection (LOD), robustness and stability were presented. The method has been applied to the quantitative determination of the fatty acid content in different food samples: edible oil, dairy products rich with omega-3 fatty acids, different food supplements, baby food, etc.     

Tropane alkaloid contamination of agricultural commodities and food products in relation to consumer health: Learnings from the 2019 Uganda food aid outbreak

Tropane alkaloids (TAs) are secondary plant metabolites derived mainly from Solanaceae plant families, with the most virulent invasive species being Datura stramonium. Datura stramonium commonly grows in cereal fields and produce TAs (e.g., hyoscyamine and scopolamine) which may accidentally contaminate cereals (and cereal-based foods) at occasionally high levels. Dietary exposure to TAs can be toxic and depending on the dose ingested can cause outcomes ranging from anticholinergic effects to acute poisoning and death. In 2019, 315 adults became ill and another five adults died in Uganda following consumption of a “Super Cereal” (a fortified blended food) that was later confirmed to be contaminated by TAs—a scenario which provoked this holistic review on TAs in foodstuffs. Thus, this article provides information on the history, development, occurrences, exposures, and human legislative and health benchmarks for TAs. It describes control strategies for reducing TA contamination of agricultural commodities and resultant health implications following consumption of TA contaminated foodstuffs. Adequate application of food safety control measures (including maximum limits) and good practices, from the start of cereal cultivation through to the final stages of manufacturing of food products can aid in the reduction of seeing toxic plants including D. stramonium in cereal fields.