A review of the properties and usage of methyl bromide as a fumigant

The properties which make methyl bromide an effective fumigant and the range of commodities treated with it are reviewed. The problems associated with the various situations in which fumigations are carried out and the methods of application used are discussed, and consideration is given to the toxicity of methyl bromide to man and other mammals, and to the risks involved in its use. Analytical methods for determining methyl bromide in air and residual bromide in foodstuffs are reviewed and a Table of physical properties and other reference data is given as an Appendix.     

食品中全氟化合物分析技术研究进展

全氟化合物(perfluorinated compounds,PFCs)是一类人工合成的脂肪烃类化合物,自上个世纪50年代合成以来,该类化合物以其优良的稳定性及表面活性作为加工助剂被应用于多种民用及工业领域,如纺织品、灭火器和油漆等行业。近些年来越来越多的调查研究发现,在空气、沉积物、饮用水、海水和食品中检测出全氟类化合物。膳食作为人体暴露PFCs的重要途径之一,已受到了各国研究人员的重视。本文综述了食品中PFCs的检测技术的研究进展,讨论了不同食品中PFCs的前处理及检测方法,当前主要采用离子对液液萃取和液固萃取,WAX柱净化提取液,液相色谱-质谱联用技术定量分析食品中的PFCs。由于食品中PFCs处于痕量水平,对该类物质的检测方法中空白本底的控制尤为重要。另外,全氟化合物存在的多种同分异构体之间的差异将是研究人员对其准确监测的困难之一。     

Potential carcinogenic heterocyclic aromatic amines (HAAs) in foodstuffs: Formation,extraction, analytical methods,and mitigation strategies

During the heat treatment of proteinaceous food, heterocyclic aromatic amines (HAAs), a kind of strong mutagens/carcinogens are formed. HAAs can be classified into two major groups based on the heating temperature, which are thermic HAAs generally formed in 150 to 300 °C and pyrolytic HAAs produced above 300 °C. This review focuses on the formation mechanisms of HAAs and identifies different mechanisms of the formation of HAAs in foodstuffs. Moreover, an overview of the available extraction, purification methods, and instrumental analytical methods in the last two decades is shown to determine the HAAs in various foodstuffs. Finally, based on the factors that affect the formation of HAAs in heat‐processed foodstuffs, such as the cooking method, food type, the recipe, and the content of substances with enhancing or inhibiting effects on the formation of HAAs, this review also highlights the most promising strategies for mitigating HAAs, which include adjusting cooking methods or process conditions, adding natural product extracts, antioxidants or other compounds, or reasonable selection of types of foodstuff. The review intends to provide a broad but comprehensive understanding of the formation, extraction, purification, analytical methods, and possible mitigation strategies for isolated and identified HAAs.     

A review of extraction,analytical and advanced methods for determination of pesticides in environment and foodstuffs

Pesticides are widely applied to prevent unwanted pests from attacking crops and livestock which led to their access into the environment. Overuses of pesticides in environment are presence of pesticide residues and their metabolites that are causing serious detrimental effects on human health and all other living organisms. Several severe diseases (Cancer, chronic obstructive pulmonary disease, birth defects, infertility) and more damages of human health are associated with the exposure of pesticides. The maximum residue limits for pesticides have been regulated by the Codex Alimentarius Commission and European Union to protect human health. Thus, monitoring these compounds is extremely important to ensure that only permitted levels of pesticide are consumed. To date, several techniques have been developed for pesticide detection, from conventional analytical to advanced detection techniques. The conventional analytical methods are gas chromatography and high performance liquid chromatography coupled with various detectors involved a sample preparation step prior to further analysis. Advanced detection methods refer to the sensors development such as electrochemical, optical, piezoelectric and molecular imprinted polymer. In this review, we summarized and explained the available analytical and advanced methods for determination of pesticides compound in environment and foodstuffs. Also, pesticides classification and its toxicity, and available extraction methods are briefly discussed.     

赭曲霉毒素A分析方法进展

赭曲霉毒素A(OchratoxinA,OTA)是曲霉属和青霉属的某些菌种产生的一种具有致癌、致畸、免疫抑制和肝肾毒性的有毒代谢产物,世界上许多国家已制定了食品中OTA的相关法规和标准,而准确、可靠、灵敏的分析OTA方法是法规标准实施的重要依据。有机溶剂与酸(或碳酸氢钠)的混合溶液是提取食品中OTA的常用溶剂系统;含有OTA提取液的净化手段包括液液分配、固相柱萃取和免疫亲和层析等;反相液相色谱配荧光检测器、酶联免疫吸附法和液相色谱质谱联机是分析OTA的常用方法,本文就OTA的检测方法进行综述。     

Valorisation of food wastes to produce natural pigments using non-thermal novel extraction methods: a review

Waste or by-products produced during food processing can be used as a potential source of bioactive compounds including natural pigments. Natural pigments/colourants have numerous health benefits whereas the synthetic colourants have many negative effects on human health. Thus, there is a considerable interest worldwide in pigments extraction from natural sources. Conventional extractions such as soxhlet extraction, water distillation, and solvent extraction have many limitations such as large solvent consumption, long extraction time, and low extraction yields. Therefore, novel techniques such as high pressure, ultrasound, negative pressure and electric field have been employed to assist the pigment extraction process. The novel extraction methods are being developed with the primary aim of higher pigment yield, lower solvent consumption, minimised environmental effects and the convenience of extraction. With this perspective, the present review provides recent insights into the recovery of natural pigments from food wastes/by-products and the application of novel non-thermal technologies for their recovery.     

水酶法提取植物油脂技术研究进展

水酶法是在水代法基础上发展起来的一种现代提取植物油脂新技术。水酶法主要利用生物酶的酶解作用促进植物油脂的游离,与传统压榨法、有机溶剂浸出法及超临界萃取法等相比,其工艺简单,对设备的要求低,无高温处理及有机溶剂残留,油脂品质更好。因此,水酶法是一种"绿色、安全、营养"的提油新技术。本文介绍了水酶法提取植物油脂的技术原理及工艺特点,生物酶的选择与生物酶在水酶法提油中的应用现状,比较了水酶法与其他传统方法制备的植物油脂的品质;并重点讨论了水酶法提取植物油脂技术研究的关键问题,即:水酶法提油过程中乳化液的形成机制及破乳技术;同时,针对水酶法提油技术存在的用酶量大、成本较高及废水处理等问题提出了可能的解决途径,并对其应用前景进行了展望。     

Analytical methods for the determination of acrylamide in food products: a review

In early 2002, the Swedish National Food Administration reported high acrylamide levels in heat-treated carbohydrate-rich foods. Consequently, intensive activity began examining the many different types of food, and thousands of analyses have been undertaken world wide. Measurement data have been published in many different types of media. Within this flood of publications, there are only a limited number of articles concerned with the technical aspects of the measurements. This review focuses on the state-of-the-art in the analysis of acrylamide in foodstuffs. It covers information on methods from peer-reviewed articles and other sources (e.g. a survey carried out among official and private laboratories of the Member States of the European Union). Alternative methods are presented and discussed alongside the more common measurement techniques for acrylamide in foodstuffs. Special attention is given to sample preparation. The greatest differences between the analytical methods was for acrylamide extraction and clean-up. The influence of different extraction techniques or extraction solvents/solvent mixtures on the measurement results has not yet been fully investigated. There is also a lack of understanding about the sample clean-up. Since both might have a large impact on the results of the analysis, this review should also be considered as a basis for further investigations.     

Analysis of Isoflavones in Foods

In recent years the nutritional and bioactive properties of foods are being intensively investigated with a view to control, in addition to food quality, their possible influence on human health. Because of this, there is a growing demand for rapid, selective, sensitive, and validated methods for analysis and quantification. Bioactive plant compounds include those with weak estrogenic activity (phytoestrogens), among which are the isoflavones. Some of the beneficial activities that have been attributed to isoflavones are anticarcinogenic activity, the prevention of cardiovascular disease, the improvement of bone health, and antioxidant activity. The objective of this work is to provide an updated review of the methods used in sample preparation and subsequent analysis for the determination of isoflavones in food samples, including both soybean and soy products, as well as other foods with low isoflavone contents. The review focuses on the most common sample preparation techniques used during the last 10 years, including both conventional solvent extraction and other more recent extraction techniques. Separation and detection methods, including current trends in liquid chromatography analysis, such as the use of monolithic columns or ultra‐high‐pressure liquid chromatography, are also discussed.     

Extraction Methods of Citrus Peel Phenolic Compounds

Several extraction methods have been reported in the literature for the extraction of phenols from citrus peel. Extraction methods may cause a degradation of phenolic compounds due to high applied temperature and pressure or long extraction times (conventional solvent extraction, high-pressure extraction). However, other extraction methods are limited by the polarity of phenolic compounds (supercritical CO₂ extraction). Novel techniques of extraction of bioactive compounds have been developed in order to shorten the extraction time, increase the extraction yield, and prevent the degradation of the phenolic compounds. This review provides a critical comparison of the different extraction methods of citrus peel phenolic compounds. The review compiles valuable data that could be useful for the choice of an appropriate extraction method for bioactive compounds from vegetables sources. The main parameters influencing the extraction yield are also discussed.     

基于液相色谱和液质联用法的动物源性食品中氟喹诺酮类与酰胺醇类药物残留检测研究进展

氟喹诺酮类和酰胺醇类药物是畜禽生产中常用的广谱高效抗生素，应用广泛，但药物残留超标现象频出。液相色谱与液质联用法是目前检测氟喹诺酮类和酰胺醇类药物残留的主要方法，当前国内标准规定的检测方法仅能在牛奶中同时检测这两类兽药残留，在其他基质中鲜有报道，因此亟需建立和优化氟喹诺酮类和酰胺醇类药物在不同基质中同时检测的方法。本文概述了液液萃取、固相萃取、QuEChERS方法和加速溶剂萃取等四种常用前处理技术，具体论述了纳米材料吸附剂这一研究热点的应用情况，并从色谱和色谱质谱联用法的角度，总结并论述了不同基质条件、仪器配置、液相条件对方法性能参数的影响，以期为动物源性食品中兽药残留的检测和监管提供参考。     

液质联用检测水产品中氯霉素、氟苯尼考和甲砜氯霉素的残留量

建立了采用液相色谱-质谱同位素稀释法同时测定水产品中氯霉素、氟苯尼考、甲砜氯霉素三种残留药物的方法.样品采用碱化乙酸乙酯提取,同位素内标法定量.氯霉素、氟苯尼考、甲砜氯霉素三种药物的定量限(LOQ)分别为0.05 ng/mL、0.5 ng/mL、0.7 ng/mL;药物质量浓度分别在0.05～1.2 ng/g、0.5～20.0 ng/g和0.7～28.0 ng/g内,与相应的峰面积比值呈良好的线性关系,并且在鱼肉中氯霉素、氟苯尼考、甲砜氯霉素回收率分别为92.2%～125.5%、78.6%～102.7%和79.4%～121.0%,在虾肉中分别为98.5%～128.4%、73.5%～109.6%和87.7%～122.8%.该法具有简单、快速、简化样品前处理步骤等优点.     

Understanding the potential benefits of thyme and its derived products for food industry and consumer health: From extraction of value-added compounds to the evaluation of bioaccessibility,bioavailability, anti-inflammatory,and antimicrobial activities

ABSTRACT

Natural bioactive compounds isolated from several aromatic plants have been studied for centuries due to their unique characteristics that carry great importance in food, and pharmaceutical, and cosmetic industries. For instance, several beneficial activities have been attributed to some specific compounds found in Thymus such as anti-inflammatory, antioxidant, antimicrobial, and antiseptic properties. Moreover, these compounds are classified as Generally Recognized as Safe (GRAS) which means they can be used as an ingrident of may food producs. Conventional extraction processes of these compounds and their derived forms from thyme leaves are well established. Hoewever, they present some important drawbacks such as long extraction time, low yield, high solvent consumption and degradation thermolabile compounds. Therefore, innovative extraction techniques such as ultrasound, microwave, enzyme, ohmic and heat-assisted methods can be useful strategies to enhance the exytraction yield and to reduce processing temperature, extraction time, and energy and solvent consumption. Furthermore, bioaccessibility and bioavailability aspects of these bioactive compounds as well as their metabolic fates are crucial for developing novel functional foods. Additionally, immobilization methods to improve stability, solubility, and the overall bioavailability of these valuable compounds are necessary for their commercial applications. This review aims to give an overall perspective of innovative extraction techniques to extract the targeted compounds with anti-inflammatory and antimicrobial activities. Moreover, the bioaccessi-bility and bioavailability of these compounds before and after processing discussed. In addition, some of the most important characteristics of thyme and their derived products discussed in this paper.     

Formation and extraction of persistent fumigant residues in soils

Fumigants are commonly thought to be short-lived in soil, but residues have been found in soils years following application. In this study, formation and extraction of persistent soil fumigant residues were investigated. Fumigants 1,3-dichloropropene (1,3-D), chloropicrin (CP), and methyl isothiocyanate (MITC) were spiked into Arlington, Glenelg, and Hagerstown soils and incubated for 30 d under controlled conditions. The incubated soils were evaporated for 20 h prior to extraction with a variety of organic solvents at different temperatures. Extraction with acetonitrile in sealed vials at 80 degrees C for 24 h was the most efficient method to recover persistent soil fumigant residues. At application rates of 1000-1700 mg (kg of soil)(-1), persistent residues of 1,3-D, CP, and MITC in the three soils ranged from 5 to 67 mg kg(-1). The residue content increased with application rate, correlated positively with soil silt content, decreased dramatically as indigenous organic matter (OM) was removed, and changed little with external OM addition. Adsorption to clay surfaces was not important in fumigant retention, while pulverization of soil aggregates significantly decreased persistent fumigant residues. The results suggest that persistent fumigant residues are retained in soil intra-aggregate micropores resulting from binding clay flocs and silt particles by humic substances.     

Industrial relevance of Tamarindus indica L. by-products as source of valuable active metabolites

Tamarind (Tamarindus indica L.) pulp is highly consumed due to the appreciable sensorial attributes. However, the fruit processing generates from 50 to 70% of residue, corresponding to peel, fiber, and seeds; a biomass still unexplored and usually discarded in the environment. In this perspective, the present review highlights and summarizes the current literature data about the main bioactive compounds associated to by-products from tamarind processing. Then, to balance the lack of information on these residues, an overview on extraction methods is also presented, linked to the recovery of relevant compounds from these residues and possible applications for the resulting products. Phenolic compounds, fatty acids, and polysaccharides are the main classes of substances from tamarind by-products, which, when processed, are submitted to traditional extraction methods (Soxhlet and maceration). To spread the environmental appeal of these residues as viable biomass, non-traditional extraction methods, still underused for tamarind by-products, are valued. These methods are interesting alternatives to obtain valuable compounds adequate for functional foods, packaging formulations, medicines, and cosmetics.     

Current technologies and new insights for the recovery of high valuable compounds from fruits by-products

The recovery of high valuable compounds from food waste is becoming a tighten issue in food processing. The large amount of non-edible residues produced by food industries causes pollution, difficulties in the management, and economic loss. The waste produced during the transformation of fruits includes a huge amount of materials such as peels, seeds, and bagasse, whose disposal usually represents a problem. Research over the past 20 years revealed that many food wastes could serve as a source of potentially valuable bioactive compounds, such as antioxidants and vitamins with increasing scientific interest thanks to their beneficial effects on human health. The challenge for the recovery of these compounds is to find the most appropriate and environment friendly extraction technique able to achieve the maximum extraction yield without compromising the stability of the extracted products. Based on this scenario, the aim of the current review is twofold. The first is to give a brief overview of the most important bioactive compounds occurring in fruit wastes. The second is to describe the pro and cons of the most up-to-dated innovative and environment friendly extraction technologies that can be an alternative to the classical solvent extraction procedures for the recovery of valuable compounds from fruit processing. Furthermore, a final section will take into account published findings on the combination of some of these technologies to increase the extracts yields of bioactives.     

大气压化学电离-液相色谱串联质谱法测定油基食品中的18种邻苯二甲酸酯类化合物

根据2011年6月卫生部公示的食品中17种禁用邻苯二甲酸酯的名单,本方法采用相色谱-串联四极杆质谱建立了快速测定含油食品中18种邻苯二甲酸酯（PAEs）含量的分析方法。食品采用乙腈提取,加入水稀释后,正己烷液液萃取,样液浓缩至干后,甲醇定容。采用C18液相色谱柱分别在等度与梯度两种洗脱程序下分离,大气压化学正离子电离,多反应监测模式测定。在该优化方法条件下,18种邻苯二甲酸酯检测限（LOQ）在0.05~0.5 mg/kg之间,方法回收率为53.4%~107.9%,相对标准偏差（RSD）为7.2%~24.6%。应用本方法分析了植物油、起酥油、辣椒酱、豆辨酱、饼干等多种食品中18种邻苯二甲酯类物质含量,经与标准方法相比,表明本方法操作简单、测定结果准确,可以作为食品中18种邻苯二甲酸酯类化合物的确证方法。     

A critical comparison between traditional methods and supercritical carbon dioxide extraction for the determination of tocochromanols in cereals

Traditional methods and a supercritical CO₂ (SFE) method for the extraction of tocochromanols (tocopherols and tocotrienols) from cereals were compared. The tested SFE procedure showed no significant selectivity towards the different tocochromanols but the extraction yield obtained (about 85%) can be compared with the conventional extraction techniques like Soxhlet and Folch. Like traditional methods, SFE extracts free and esterified tocochromanols and is unable to give a total recovery of tocochromanols strictly bonded to matrix components, as shown after hot saponification of the lipidic extracts and the residues of extraction. The low solvent consumption and the short analysis time are the main advantages of the method proposed here compared with the classic solvent extraction methods.     

采用不同提取方法、利用超高效液相色谱-串联质谱检测鸡肉中喹诺酮类药物残留的影响

研究不同种类提取溶剂、超声时间、净化体积、加标量条件下,鸡肉中7种喹诺酮类药物含量的变化,分析不同提取方法对检测鸡肉中兽药残留的影响.结果显示,选用含0.2％甲酸的乙腈/水(80+20)溶液作为提取鸡肉中喹诺酮类药物的最佳溶剂.超声提取10min时,提取效果最佳.上样体积为3mL时回收率较高.加标量为5ng/g水平上的...     

食品中丙烯酰胺分析的样品前处理技术

近年来,关于食品中丙烯酰胺危害食品安全的问题倍受关注,在检测过程中,样品的前处理技术直接影响检测的效率和准确率。综述了近年来食品中丙烯酰胺分析的样品前处理技术,对加速溶剂萃取和固相微萃取等新技术进行了评述,并对食品中丙烯酰胺分析的前处理技术的发展方向进行了讨论。