太赫兹光谱技术在储粮品质检测中的应用

近年来粮食质量与安全问题备受国民的关注,了解粮食在储藏过程中品质的变化趋势,特别是在早期阶段对其劣变状况进行快速、准确检测是当前粮食行业的重要任务之一。太赫兹光谱探测与成像技术具有快速、无损、衰减性小、无电离辐射伤害等特性,现已成为无损检测技术的研究热点,在人体安全检查、环境监测、病变诊断、农产品质量控制等诸多领域取得了阶段性进展,在储粮品质检测方面也具有良好的应用前景。本文主要对太赫兹时域光谱技术的探测原理和光学参数提取以及成像技术进行了综述,重点阐述了该技术在储粮品质鉴别与分类、储粮新陈度、储粮真菌污染以及储粮害虫检测方面的应用研究,并对太赫兹光谱技术在粮食品质快速检测中的发展趋势和应用前景进行了展望。     

高光谱成像技术在红肉食用品质检测中的应用研究进展

高光谱成像技术是一种集光谱技术与计算机视觉技术为一体的无损检测技术,该项技术能快速、全面、无损地获取肉品的内外部信息,在红肉食用品质的检测中具有广泛应用。本文在简述高光谱成像原理的基础上,详述近年来高光谱成像技术在红肉制品食用品质方面的应用,并对该项技术存在的问题及应用前景进行概述,以期为红肉无损检测的研究提供参考。     

基于太赫兹反射成像技术的花生空果无损检测

目的 基于太赫兹反射成像技术(Terahertz Reflection Imaging Method, THz-RIM)实现花生空果无损检测,为太赫兹技术在农产品及食品快速无损检测中的应用奠定基础。方法 利用太赫兹脉冲光谱仪TeraPulse 4000及反射成像附件和采集软件,在0.2 mm采集步长下对去壳花生仁进行太赫兹反射成像预实验,确定出正式实验的图像颜色模式为hot模式。人为制备若干个花育36号满仁花生果样本和空果样本(仅有一粒花生仁),在与预试验相同的条件下采集样本光谱图像,以时域/频域2点外相加成像(Integrated Time Slice)重构方式进行图像重构, 突出花生空果样本图像的显著几何特征。结果 通过太赫兹反射图像可以实现满仁与花生空果样本的检测区分,但图像细节仍然比较模糊,需进一步提高图像清晰度。采用数字图像方法进行图像增强,利用OpenCV-Python提高图像的亮度、色度、对比度及锐度。提升对比度后的图像可观测度最高,且空果图像中黑色部分面积占比最大,与含仁部分对比最为明显,可以实现空果及满仁花生果的快速区分。结论 探索结果表明,THz波对花生外壳具有良好的穿透性,利用THz-RIM技术结合OpenCV-Python数字图像处理方法进行花生空果无损检测具有可行性,利用太赫兹光谱技术对油料作物内部品质进行无损检测研究具有极大潜力。     

基于太赫兹时域光谱技术的面粉品质快速无损检测研究

太赫兹(THz)波能够穿透大多数干的介电材料(塑料、陶瓷、衣物等),可实现对带包装物品的质量检测。为了研究THz光谱技术对带包装面粉的无损检测,首先对不带包装面粉进行太赫兹时域谱可行性分析及建模研究。对101份不同种类的面粉样本,用Tera Pulse 4000的太赫兹脉冲光谱仪采集了其太赫兹时域谱,对光谱预处理后,用偏最小二乘法(PLS)算法建立了面粉中3个指标水分、灰分、面筋的定量分析模型。各模型的预测相关系数都在0.89以上,研究结果表明,通过太赫兹时域光谱技术对面粉品质进行无损、快速检测具有可行性,对下一步太赫兹光谱技术直接对带包装的面粉进行检测研究奠定了坚实的基础。     

粮食真菌毒素污染的无损检测方法研究进展

粮食种植、加工和储运过程易受真菌毒素污染,严重威胁人畜健康。然而,目前传统的真菌毒素检测方法存在过程繁琐、时效性差或灵敏度低等缺点,难以满足现场快速准确检测的需要,日益成为制约粮食质量安全的瓶颈。现代无损检测技术作为一种新兴的检测技术,可以在不破坏样品的情况下对其进行质量评价,是粮食品质在线、实时检测的一个重要发展方向,在粮食真菌毒素污染的快速分析方面具有巨大的应用潜力。本文重点综述了近红外光谱、高光谱图像、电子鼻等典型无损检测技术在粮食真菌毒素污染检测分析中的最新研究进展,讨论了各种技术的优点及限制因素,并对其应用前景进行了展望。     

太赫兹波谱技术在木材工业中的应用

介绍了太赫兹波谱技术的基本特性,针对国外太赫兹波谱技术在木材工业中的应用研究现状,进行了分析。介绍了利用太赫兹时域光谱技术进行木材光学特性及含水率测定方法研究;介绍了利用太赫兹成像技术在木结构内部隐藏缺陷的无损检测等方向的研究成果。提出现阶段太赫兹波谱技术在木材工业领域的应用发展方向。     

高光谱成像在食品质量评估方面的研究进展与应用（二）

为了保证食品质量与安全,满足消费者需要,需要在食品生产、加工过程中对食品品质和安全信息进行实时检测。高光谱成像技术作为一种无损检测方法,能够实现食品品质和安全信息的快速、高效、准确检测。作为本综述的第二部分,本文主要介绍高光谱成像技术在水果与蔬菜的品质检验方面的应用,同时对其在奶制品、谷类、蘑菇等方面的研究成果也进行介绍,最后叙述高光谱成像技术的应用前景及目前的局限性。     

牛肉品质无损检测技术研究进展

牛肉营养物质丰富,是受消费者青睐的肉类之一。牛肉品质的优劣影响市场价格、消费者的购买意愿与满意度,因此牛肉品质的检测工作十分重要。目前传统的牛肉品质检测方法存在耗时、样品损坏以及操作复杂等问题。近年来,无损检测技术凭借其快速、高效、无损、绿色无污染的优势被广泛应用于牛肉品质检测。本文对无损检测技术在牛肉的品质分析（感官品质、营养品质和其他品质）进展进行了总结,系统阐述了近红外光谱、拉曼光谱、高光谱成像、电子舌和电子鼻等无损检测技术的原理,详细论述了近5年内无损检测技术在牛肉品质分析的进展,提出了无损检测技术在牛肉品质分析中存在的问题,并对未来的应用前景进行了展望,以期为牛肉品质无损检测技术的研究与应用提供参考。     

食品质量与安全中的THz技术应用进展分析

近年来,半导体材料科学与超快激光技术快速发展,为太赫兹技术奠定了可靠的、稳定的、实用的基础。促进了太赫兹技术在光谱学与成像技术方面的应用,尤其是在食品质量与安全领域上有着极大的应用机会,太赫兹技术已经展现出了巨大的优势。本文总结了太赫兹光谱系统与太赫兹成像系统的原理,进一步介绍了太赫兹技术在食品质量与安全领域中的应用。另一方面,探讨了太赫兹技术在食品质量与安全检测领域中存在的问题及发展。     

基于太赫兹技术的小麦粉品质快速检测研究

该研究针对目前小麦粉品质方面检测方法存在的问题,提出利用太赫兹光谱技术对小麦粉进行快速无损品质检测研究。使用光谱仪与成像仪,采集了不同种类小麦粉样本的太赫兹光谱,使用TQ Analyst软件结合距离匹配法对小麦粉的太赫兹扫描光谱进行定性分析研究,富强粉和麦芯粉成功分类,模型性能指数达到88.9%,预测准确率达100%。使用OPUS软件结合偏最小二乘法（PLS）和一阶导数+矢量归一化（SNV）进行定量分析研究,水分定量模型R2为91.18%,交叉验证均方根为0.182;灰分定量模型 R2为83.37%,交叉验证均方根为0.064,最终通过实验结果分析得出太赫兹技术在食品品质检测方面的可行性。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.