Ochratoxin A in Wines

Mycotoxins are produced by fungi, commonly known as mold. Ochratoxins are a dangereous group of mycotoxins produced as secondary metabolites by several fungi of the Aspergillus or Penicillium families. Ochratoxin have been detected in foods and beverages, including grape juice and wine. Several analytical methods have been developed for detection of Ochratoxin A [OTA] in wine. In this article, the chemical structure, biosynthesis, formation, microorganisms, determination methods, regulations and the removal of OTA have been reviewed.     

A Simple and Fast HPLC Method to Determine Lycopene in Foods

Carotenoids, among which lycopene—the principal pigment found in tomatoes—are lipophilic compounds which play a very important role in human health and nutrition. They are also recognised as strong antioxidants due to their ability to trap singlet oxygen and eliminate the peroxyl radical. The availability of reliable information on lycopene content of foods is essential both for the evaluation of diet and for epidemiological research relating the intake of lycopene. This paper describes a simple and fast HPLC/UV method for lycopene determination in a wide range of food products. All-E-lycopene together with its Z isomers were eluted isocratically using a carotenoid C30 reversed-phase column. The in-house validated HPLC method had a limit of quantification of 60 ng lycopene/g product and high precision and accuracy. The analytical method was successfully applied to several food products such as raw vegetables and fruits and also processed foods. Tomato and tomato-containing products contained the highest amounts of lycopene. While raw foods and minimally processed foods contained above 94% of all-E-lycopene, processed foods (such as soups, pasta sauces, pizza and cheese) contained from 76% to 87% of all-E-lycopene.     

Mycotoxin analysis: An update

Mycotoxin contamination of cereals and related products used for feed can cause intoxication, especially in farm animals. Therefore, efficient analytical tools for the qualitative and quantitative analysis of toxic fungal metabolites in feed are required. Current methods usually include an extraction step, a clean-up step to reduce or eliminate unwanted co-extracted matrix components and a separation step with suitably specific detection ability. Quantitative methods of analysis for most mycotoxins use immunoaffinity clean-up with high-performance liquid chromatography (HPLC) separation in combination with UV and/or fluorescence detection. Screening of samples contaminated with mycotoxins is frequently performed by thin layer chromatography (TLC), which yields qualitative or semi-quantitative results. Nowadays, enzyme-linked immunosorbent assays (ELISA) are often used for rapid screening. A number of promising methods, such as fluorescence polarization immunoassays, dipsticks, and even newer methods such as biosensors and non-invasive techniques based on infrared spectroscopy, have shown great potential for mycotoxin analysis. Currently, there is a strong trend towards the use of multi-mycotoxin methods for the simultaneous analysis of several of the important Fusarium mycotoxins, which is best achieved by LC-MS/MS (liquid chromatography with tandem mass spectrometry). This review focuses on recent developments in the determination of mycotoxins with a special emphasis on LC-MS/MS and emerging rapid methods.     

Mycotoxin analysis: an update

Mycotoxin contamination of cereals and related products used for feed can cause intoxication, especially in farm animals. Therefore, efficient analytical tools for the qualitative and quantitative analysis of toxic fungal metabolites in feed are required. Current methods usually include an extraction step, a clean-up step to reduce or eliminate unwanted co-extracted matrix components and a separation step with suitably specific detection ability. Quantitative methods of analysis for most mycotoxins use immunoaffinity clean-up with high-performance liquid chromatography (HPLC) separation in combination with UV and/or fluorescence detection. Screening of samples contaminated with mycotoxins is frequently performed by thin layer chromatography (TLC), which yields qualitative or semi-quantitative results. Nowadays, enzyme-linked immunosorbent assays (ELISA) are often used for rapid screening. A number of promising methods, such as fluorescence polarization immunoassays, dipsticks, and even newer methods such as biosensors and non-invasive techniques based on infrared spectroscopy, have shown great potential for mycotoxin analysis. Currently, there is a strong trend towards the use of multi-mycotoxin methods for the simultaneous analysis of several of the important Fusarium mycotoxins, which is best achieved by LC-MS/MS (liquid chromatography with tandem mass spectrometry). This review focuses on recent developments in the determination of mycotoxins with a special emphasis on LC-MS/MS and emerging rapid methods.     

农产品及其制品中交链孢酚和交链孢酚单甲醚研究进展

交链孢菌(Alternaria spp.)是一类重要的植物病原体,能产生多种毒素,其中交链孢酚(alternariol,AOH)和交链孢酚单甲醚(alternariol monomethyl ether,AME)是目前从食物中检出的比较普遍和主要的2种交链孢毒素,可广泛污染蔬菜、水果及谷物等农产品及其制品。本文对AOH和AME的结构及理化性质、毒性、产生影响因素、生物及化学合成和污染现状等进行了综述,并对交链孢毒素限量标准的制定、快速检测方法等进行了展望。     

Ochratoxin A and Brewing Technology: A Review

Ochratoxins are a hazardous group of mycotoxins produced as secondary metabolites by several fungi of the Aspergillus and Penicillium families. Ochratoxins have been detected and determined in foods and beverages, including barley, malt and beer, at ppb levels. Varied analytical methods have been developed for the detection of ochratoxin A [OTA] in cereals and beer. Ochratoxin A has hazardous effects on health and has been classified within group 2B, as a possible human carcinogen by IARC. Scientists have expressed great concern about the presence of ochratoxin A in foods. In this article, chemical structure, biosynthesis by microorganisms, analytical methods for testing, regulations, changes during brewing, and detoxification of OTA, are reviewed. Beer poses very little risk as a source of ochratoxin in the diet.     

果蔬常见病原菌及真菌毒素的防控技术研究进展

果蔬在田间的生长过程以及采摘后的贮存、运输和加工过程中, 易发生真菌性病害, 不仅可引起腐烂或腐败, 带来严重的经济损失, 部分病原菌还可能产生真菌毒素对人体造成潜在危害。真菌毒素是一类由丝状真菌在适宜条件下产生的有毒次级代谢产物, 是继农药残留、重金属污染后, 影响果蔬质量安全的又一类关键风险因子, 具有强毒性。链格孢毒素、赭曲霉毒素、展青霉素是存在于果蔬及其制品中主要的真菌毒素种类。本文综述了近年来果蔬中常见病原真菌及其真菌毒素, 并阐述了真菌毒素防控方法, 包括物理、化学和生物方法, 对未来果蔬中真菌毒素的防控研究方向进行了展望, 以期为该领域研究者提供参考。     

Microbiology of Fresh Produce: Route of Contamination,Detection Methods,and Remedy

Fresh fruits and vegetables are an important part of a healthful diet. They provide vitamins, minerals and fiber to help keep our body healthy. Occasionally, fresh fruits and vegetables can become contaminated with harmful bacteria or viruses, which are also known as pathogens. The major family of pathogen associated with food are members of Enterobacteriaceae which commonly form a part of microbiological criteria and their presence is traditionally related to hygiene and safety of foods. Organic fertilizers, irrigation water quality and soil are major source of contamination. For removal of pathogens, various decontamination procedures are also followed to reduce microbial load on the fruits. These are chemical preservatives and irradiation. Microbiological study of fresh produce can be done by various phenotypic, biochemical and molecular techniques so that pathogen can properly be identified. The World Health Organization (WHO) developed global risk communication message and training materials to assist countries in strengthening their food educating programs. There is a need for improved surveillance systems on food-borne pathogens, on food products and on outbreaks so that comparable data are available from a wider range of countries.     

梨果实及其制品中真菌毒素的污染、检测及控制方法研究进展

梨果实营养丰富, 水分含量较高, 在生产、采收和贮运过程中易受病原菌侵染, 特别是在贮藏期间发生真菌性病害后腐烂霉变, 产生并积累各种真菌毒素。本文首先介绍了链格孢毒素、展青霉素、橘霉素和黄曲霉毒素的毒性和在梨果实及其制品中的污染状况, 其次, 对在梨和其制品中应用的薄层色谱法和液相色谱-质谱联用法的特点和应用实例进行了综述, 最后, 总结了果品中真菌毒素的降解方法, 并对有效防控真菌毒素的重点研究方向进行了展望。当前国内对于梨果实及其制品中真菌毒素的研究报道很少, 今后应加强这方面研究, 明确当前真菌毒素的种类以及污染水平, 并重点开展有效防控真菌毒素的研究, 提高我国梨果实及其制品的质量安全水平。     

抗真菌性乳酸菌生物保护剂的研究进展

霉菌和酵母不仅引起果蔬、谷类、乳制品和肉制品等食品及农产品腐败变质,造成巨大的经济损失,而且霉菌还产生有害于人体健康的黄曲霉毒素、伏马菌素、单端孢霉烯、赭曲霉素A和棒曲霉素等真菌毒素,给食用者带来潜在的食品安全隐患。随着消费者对鲜活和微加工食品的需求不断增加,化学防腐剂在食品中应用受到限制,食品生物保护剂研究及应用已成为热点。乳酸菌通过生态位竞争、形成酸性环境和产生各种代谢产物对致病菌和腐败微生物具有较强的拮抗作用,作为一新型生物保护剂已广泛应用于各种食品中。本文对食品中抗真菌性乳酸菌的筛选和应用、乳酸菌产生的抗真菌代谢产物以及发展趋势进行综述,为进一步探究乳酸菌抗菌机理,研发高效食品生物保护剂提供借鉴与参考。     

国内外水果真菌毒素的限量及检测方法标准分析

水果在采收、运输和贮藏过程中易受到病原微生物污染,产生并积累各种真菌毒素。由于不适宜的加工工艺,这些真菌毒素会迁移至水果加工制品中,进而引起潜在风险。鉴于此,世界各国都积极制定各种标准、法规来控制真菌毒素在水果及其制品中的污染水平。本文综述了近年来我国水果中真菌毒素的现行限量标准及检测方法标准的制修订状况,并与国外相应的标准进行了对比和探讨,分析了在我国建立水果中真菌毒素限量及检测方法标准的紧迫性和重要性,以期为相关检测人员进行水果中真菌毒素检测时选择方法提供依据,同时也为政府部门制定国家标准提供参考。     

Determination of chemical hazards in foods using surface-enhanced Raman spectroscopy coupled with advanced separation techniques

BackgroundSurface-enhanced Raman spectroscopy (SERS) has been validated as a highly accurate and specific technique for the discrimination, identification, and potential quantification of different types of chemical compounds. However, its application for the detection of potential hazardous chemical targets in foods has not yet been well developed due to interferences from the complicated food matrices, which could lead to challenges in spectral deconvolution and interpretation. The accurate separation and enrichment of the analyte from food samples are major challenges for analytical chemists and food technologists.Scope and approachFour promising “capturing” techniques (molecularly imprinted polymers, aptamer, antibody, and microfluidics) coupled with SERS were introduced in this review paper for the reliable and ultrafast determination of chemical hazards in food systems. These developed “one-step” or “two-step” SERS methods can achieve accurate and sensitive detection of trace level chemical hazards in agricultural products including foods.Key findings and conclusionsTandem SERS methods can be applied for rapid and reliable detection of trace level of chemical hazards in foods.     

Mycotoxins in dairy products

Certain fungi produce chemical substances that cause toxic symptoms when food containing them is ingested by man or animals. These compounds are referred to as mycotoxins. Mycotoxins may contaminate dairy products by moulds growing on them, or by the carry-over of mycotoxins occurring in animal feedstuffs ingested by dairy cattle. An example of the first mentioned category is sterigmatocystin, a carcinogenic mycotoxin sometimes occurring on hard cheese. An example of the second category is aflatoxin M₁, a compound strongly suspected to be carcinogenic, which often occurs in milk. Due to the fact that processing of milk does not decrease the aflatoxin M₁ content, aflatoxin M₁ occurs in various dairy products. Sensitive methods of analysis for the determination of mycotoxins in dairy products have been developed in the last 10 years, most of them are based on TLC- or HPLC-separation procedures, followed by fluorimetric measurement.The most fundamental way to tackle the problem of mycotoxin contamination of dairy products is to prevent fungal growth on the dairy products or, in the case of carry-over of mycotoxins, in the crop before, during and after harvest. If measures to prevent fungal growth and mycotoxins production are not taken or fail, one can sometimes resort to physical or chemical methods to eliminate mycotoxins.     

Advanced synchrotron-based and globar-sourced molecular (micro) spectroscopy contributions to advances in food and feed research on molecular structure,mycotoxin determination,and molecular nutrition

ABSTRACT

Mycotoxin contamination has been a worldwide problem for food and feeds production for a long time. There is an obviously increased focus of the food and feed industry toward the reduction of mycotoxin concentration in both the raw materials and finished products. Therefore, both effective qualitative and quantitative techniques for the determination of mycotoxins are required to minimize their harmful effects. Conventional wet chemical methods usually are time-consuming, expensive, and rely on complex extraction and cleanup pretreatments. Synchrotron-based and globar-based molecular spectroscopy have shown great potential to be developed as rapid and nondestructive tools for the determination of molecular structure, molecular nutrition and mycotoxins in feed and food. This article reviews the common types of mycotoxins in feed and food, their toxicity, as well as the conventional detection methods. The principle of advanced molecular spectroscopy techniques and their application prospects for mycotoxin detection are discussed. Recent progress in food and feed research with molecular spectroscopy techniques is highlighted. This review provides a potential and insight into how to determine the structure and mycotoxins of feed and food on a molecular basis with advanced Synchrotron-based and globar-based molecular (micro) spectroscopy.     

谷物中DON、ZEA毒素的净化、检测、 毒性与生物脱毒技术的研究

禾谷镰刀菌在侵染谷物过程中所产生的次生代谢产物——单端孢霉烯族毒素[脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)、雪腐镰刀菌烯醇(nivalenol, NIV)]以及玉米赤霉烯酮(zearalenone, ZEA)是世界上粮食安全的一个重大问题。毒素经固液萃取技术提取后, 需要通过净化处理才能进行检测与分析。目前有多种净化技术用于毒素的净化, 如免疫亲和柱、多功能净化柱等固相萃取柱等, 以及广泛使用且简便经济的QuEChERS前处理技术。本文还介绍了禾谷镰刀菌毒素中DON、ZEA的检测方法、产毒条件、毒性以及生物脱毒技术等方面的研究进展, 旨在开发与应用更安全、高效、经济的生物脱毒技术进行毒素的防御与去除, 以提供安全、优质的粮食与食品。     

Nonthermal physical technologies to decontaminate and extend the shelf-life of fruits and vegetables: Trends aiming at quality and safety

Minimally processed fruits and vegetables are one of the major growing sectors in food industry. This growing demand for healthy and convenient foods with fresh-like properties is accompanied by concerns surrounding efficacy of the available sanitizing methods to appropriately deal with food-borne diseases. In fact, chemical sanitizers do not provide an efficient microbial reduction, besides being perceived negatively by the consumers, dangerous for human health, and harmful to the environment, and the conventional thermal treatments may negatively affect physical, nutritional, or bioactive properties of these perishable foods. For these reasons, the industry is investigating alternative nonthermal physical technologies, namely innovative packaging systems, ionizing and ultraviolet radiation, pulsed light, high-power ultrasound, cold plasma, high hydrostatic pressure, and dense phase carbon dioxide, as well as possible combinations between them or with other preservation factors (hurdles). This review discusses the potential of these novel or emerging technologies for decontamination and shelf-life extension of fresh and minimally processed fruits and vegetables. Advantages, limitations, and challenges related to its use in this sector are also highlighted.     

Development of an Indirect Competitive ELISA for Analysis of Alternariol in Bread and Bran Samples

Alternariol (AOH) is one of the major mycotoxins produced by various species of Alternaria fungi. Natural occurrences of AOH have been reported in various foods, including fruits; processed fruit products such as apple juice, tomato products; wheat and other grains; oilseeds and products thereof, such as sunflower seeds, oilseed rape meal, and flax seed/linseed; and pecans. In this study, AOH-specific polyclonal antibodies were generated and developed an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for monitoring AOH in bread and bran samples. The assay was very sensitive with a limit of detection (LOD) of 2.4?±?0.6 ng/g and a half maximal inhibitory concentration (IC₅₀) of 15.2?±?2.6 ng/g in bread and a LOD of 8.4?±?1.2 ng/g and IC₅₀ of 52.8?±?10.8 ng/g in bran extract. The assay was very specific to AOH and showed no cross-reactivity to alternariol monomethyl ether, altertoxin, altenuene, tentoxin, or tenuazonic acid. The effect of organic solvents on the assay was tested. The ELISA system tolerated methanol and acetonitrile as co-solvents at up to 5% content without significant loss of IC₅₀ value. Recoveries in all cases were greater than 75%, and the results using this method were comparable to those obtained from mass spectrometry methods. We conclude that this method is suitable for rapid detection of AOH in bread and bran samples, without expensive analytical equipment or time-consuming sample preparation.     

Recent progress in mycotoxins detection based on surface-enhanced Raman spectroscopy

Mycotoxins are toxic compounds naturally produced by certain types of fungi. The contamination of mycotoxins can occur on numerous foodstuffs, including cereals, nuts, fruits, and spices, and pose a major threat to humans and animals by causing acute and chronic toxic effects. In this regard, reliable techniques for accurate and sensitive detection of mycotoxins in agricultural products and food samples are urgently needed. As an advanced analytical tool, surface-enhanced Raman spectroscopy (SERS), presents several major advantages, such as ultrahigh sensitivity, rapid detection, fingerprint-type information, and miniaturized equipment. Benefiting from these merits, rapid growth has been observed under the topic of SERS-based mycotoxin detection. This review provides a comprehensive overview of the recent achievements in this area. The progress of SERS-based label-free detection, aptasensor, and immunosensor, as well as SERS combined with other techniques, has been summarized, and in-depth discussion of the remaining challenges has been provided, in order to inspire future development of translating the techniques invented in scientific laboratories into easy-to-operate analytic platforms for rapid detection of mycotoxins.     

Determination of protein in foods: comparison of net protein and crude protein (N × 6.25) values

The purpose of the present study was: (1) to determine net (true) protein (NP) values as sums of amino acid residues and to compare them with crude protein (PA) values; and (2) to calculate the nitrogen-to-NP conversion factors by means of linear regression analyses between the NP values and nitrogen content. The differences between NP and PA values varied between food groups. The NP values in milk and milk products were, on average, 5.5% smaller than the corresponding PA values. The corresponding figures for other foods were: meat and meat products 15.4%, fish and fish products 20.6%, cereals and bakery products 12.2%, vegetables, fruits and berries 13.9% and miscellaneous processed foods 16.1%. In the present study the nitrogen-to-NP conversion factor for milk and milk products was 5.94, meat and meat products 5.17, fish and fish products 4.94, cereals and bakery products 5.40, vegetables, fruits and berries 5.36 and miscellaneous processed foods 5.51; the general conversion factor for all foods was 5.33. The above respective factors were 5.0, 17.3,21.0, 13.6, 14.2, 11.8 and 14.7% smaller than the official factor of 6.25. We conclude that the traditional PA values (N × 6.25) deviate significantly from the NP values. We recommend that protein definitions and methods of determination should be re-evaluated in the appropriate international organizations and updated in line with current knowledge and analytical capabilities for both scientific and other purposes.