单分散的二氧化硅微球表面印迹壳层的制备及其对食品包装材料中邻苯二甲酸二苄酯的检测

以邻苯二甲酸二苄酯(DBz P)为模板,以Stber和"种子生长法"相结合获得的二氧化硅微球为载体,采用表面印迹技术成功制备了纳米印迹壳层(MIPs)。采用红外光谱与扫描电镜对其结构和形貌进行表征,同时进行了一系列的吸附性能实验,结果表明,MIPs达到平衡吸附的时间约为30 min,吸附行为符合伪二级动力学。等温吸附实验结果表明,室温条件下MIPs的最大吸附量达47.35 mg/g。对不同温度条件下的等温实验数据进行拟合发现,Langmuir模型与实验数据的吻合度比Freundlich模型更高;Scatchard拟合结果证实该印迹壳层仅含1种结合位点,且印迹位点为均相分布。选择性吸附实验表明MIPs对DBz P的吸附明显高于其他结构类似物。MIPs经10次循环吸附后,吸附效率为83%,表明MIPs具有较长的使用寿命。采用超高效液相色谱(UPLC)技术,以MIPs为吸附剂提取食品包装材料中的DBzP,其加标回收率为88.8%~93.1%,相对标准偏差低于6%。MIPs可作为食品及其包装材料中DBz P提取的备选材料。     

纸基包装材料中抗氧化剂及增塑剂向干性食品模拟物Tenax TA迁移的研究

采用改性聚苯醚多孔聚合物微球Tenax TA为干性食品模拟物,用于纤维素纸基食品接触材料中3-叔丁基-4-羟基苯甲醚(BHA)、2,6-二叔丁基-4-甲基苯酚(BHT)和邻苯二甲酸二环己酯(DCP)向Tenax TA迁移的研究,以超高效液相色谱进行测定。迁移试验以白卡纸和牛皮纸为研究对象,通过设计不同迁移时间和迁移温度下3种目标物向Tenax TA迁移的实验,获取有机化合物从纸基纤维素向Tenax TA迁移的规律。结果表明,有机化合物从纸基材料向多孔聚合物微球的迁移经历了气体吸附和脱附两个步骤。在Tenax TA吸附目标化合物的过程中,纤维素纸基材料的微观孔径尺寸越大,与迁移物的相互作用越小,迁移物迁移的速率越大,Tenax TA的吸附效率越高;当吸附达到平衡后,迁移时间的延长会引发Tenax TA中迁移物的脱附,进而导致目标化合物的迁移率下降。对45种纸基食品接触材料中目标迁移物的筛查表明,BHA和DCP分别存在于两种不同类型的纸基食品接触材料中,迁移量分别为0.027μg/dm~2和0.81μg/dm~2,均小于欧盟指令规定的特定迁移限量。     

Advances on melamine determination by micellar liquid chromatography: A review

Melamine is a toxic triazine which has been recently proven as a threat to human health. It can be ingested by several methods, being the most important the unethical adulteration of protein-rich foodstuff for economic reasons. This review presents several analytical methods, taken from the literature studies, devoted to the determination of melamine in milk, dietetic supplements, drinking and wastewater, swine kidney, plasma, and urine, using micellar liquid chromatography (MLC). We consider that the control of these samples is crucial to prevent and manage melamine intoxication. This technique has been demonstrated as an excellent tool to determine organic compounds in these matrices. We detail the optimization strategy and the obtained results in the different steps of method development, such as sample pretreatment, chromatographic separation, and validation process. The similarities and differences of the procedures have been described and discussed, as well as their advantages. The main ones were the possibility of direct injection and the efficient chromatographic elution, in spite of the complexity of the samples. Besides, it was found that the MLC procedures were fast, easy-to-handle, inexpensive, eco-friendly, safe, and useful for routine analysis. Therefore, they represent an excellent alternative to reliably evaluate the melamine concentration in that kind of samples.     

The determination and characterisation of 2-naphthyloxycarbonyl chloride derivatised biogenic amines in pet foods

The need to monitor biogenic amines levels is essential for many areas of the food industry for two main reasons: the caustic nature and potential toxicity of these amines, and the potential to use amine levels as markers for freshness and quality in foodstuffs. Optimised analysis conditions used for the determination of biogenic amines derivatised with 2-napthyloxycarbonyl chloride has been applied to different pet food samples to assess the effectiveness of this method for complex sample matrices. Further to this, the use of high-resolution mass spectrometry has enabled the previously unconfirmed derivatised form of seven biogenic amines to be established. The derivatised forms identified include as mono substituted (tryptamine and histamine), bisubstituted (putrescine, cadaverine and tyramine), trisubstituted (spermidine) and tetrasubstituted (spermine). The methodology of biogenic amine determination was performed successfully to a range of pet food products highlighting the applicability to a variety of complex sample matrices.     

食品微生物对超高压处理的逆境响应

 超高压（High Hydrostatic Pressure,HHP）作为一种非热杀菌技术,在食品工业中有着很广泛的应用,与传统的热加工处理相比,在保持食品品质、杀菌、钝酶等方面都有其明显的优势。通过对国内外相关文献的分析,对HHP处理后处于亚致死状态食品微生物的细胞膜、遗传与结构物质、机体代谢等方面,以及大部分食品微生物在应对外界的多种刺激时而进行的普遍性调控机制的研究进行了总结,探讨了经过HHP处理后处于亚致死状态的食品微生物在逆境下存活的应激反应。     

Melamine and Cyanuric Acid in Foodstuffs and Pet Food: Method Validation and Sample Screening

Hazardous levels of melamine in food and feed products have been of great concern after the outbreak of contamination reported in Chinese commodities in 2008. Despite the existence of several analytical methods for melamine (MEL) detection in food, few provide a full validation data set, especially when MEL and cyanuric acid (CYA) are analyzed simultaneously. The aim of this study was to validate an analytical methodology for MEL and CYA analysis in foodstuffs by GC-MS after trimethylsilylation with N,O-bis(trimethylsilyl)trifluoroacetamide. Linearity was obtained in the range of 0.4 to 800 mg/kg for both compounds, with limits of detection (LODs) of 0.15 and 0.05 mg/kg for MEL and CYA, respectively. Screening in 20 food products [3 soya milk powder, 1 baby milk powder, 3 soya powder, 13 diversified cookies and biscuits (8 from China and 2 from Portugal), and 3 dog food) revealed MEL incidence in 55% of the cases, with a maximum concentration of 3.4 mg/kg. CYA was not detected in all samples.     

Abilities of Partial Least‐Squares (PLS‐2) Multivariate Calibration in the Analysis of Quaternary Mixture of Food Colors (E‐110, E‐122, E‐124, E‐131)

Abstract

Sunset Yellow (SY), Carmoisine (C), Ponceau 4R (P), and Patent Blue V (PB) are synthetic organic dyes which are under governmental regulations all over the world because of their toxicity and carcinogenicity.

In this study, a simple and fast analytical procedure was proposed for the simultaneous determination of food dyes (SY, C, P, and PB) in powder drinks by means the partial least‐square treatment of spectrophotometric absorbance between 450 –730 nm, taken at 10 nm intervals. The experimental calibration matrix was constructed with 27 samples. The concentration ranges considered were 2, 3, 4 µg · ml^?1 for SY, 7, 8, 9 µg · ml^?1 for C, 9, 10, 11 µg · ml^?1 for P, and 0.3, 0.4, 0.5 µg · ml^?1 for PB. The method was applied to the determination of dyes in different commercially available powder drinks. The results obtained by the application of the PLS‐2 method were statistically compared with those obtained by an HPLC method using the F and t tests. Very similar values were found by two methods. No time consuming pretreatment was needed and this method also provides rapid, accurate and economical analysis of these colors.     

离子色谱法检测食品添加剂焦碳酸二甲酯中的氯离子

建立离子色谱法检测食品添加剂焦碳酸二甲酯（DMDC）中的杂质氯离子的方法。样品用水溶解超声定容后,采用SH-AC-1阴离子交换柱（250mm×4．6mm,5μm）分离,抑制电导法检测。考察了淋洗液种类、浓度对氯离子与干扰离子分离度的影响。最佳色谱条件：以0．005mol／L的四硼酸钠水溶液为淋洗液,流速1．0mL／min。在此条件下,样品中的氯离子可以和其它干扰离子分离,而且分离度达3．0以上,峰形对称。在氯离子浓度为0．1～5．0mg／L的范围内,可获得良好的线性关系,线性相关系数大于0．999;氯离子检出限（S／N=3）达0．007mg／L,加标回收率为97．5％～98．9％。该方法可以用于食品添加剂DMDC中氯离子的测定。     

食品中化学添加剂的功能与风险控制*

食品中的化学添加剂是指由化学方法合成的一类食品添加剂。本文探讨了食品中化学添加剂产生和发展的原因,指出化学合成的食品添加剂是天然物质群的一种补充与完善,概述了化学合成食品添加剂的一般性质和功能,介绍了食品添加剂联合专家委员会(JECFA)、美国、欧盟和中国对食品添加剂进入市场前的安全性评价程序和方法,以及美国、欧盟和中国在化学添加剂投入使用后实施监督管理的机构、法律依据、质量标准等,总结了影响食品中化学添加剂安全风险控制的主要因素,最后在此基础上,提出如何从政府、企业、科研三方面完善风险控制体系和有效保障食品安全的建议。     

多元校正模型用于拼色食品中混合色素的同时测定

采用多元校正模型,不经分离,用吸光光度法同时测定拼色食品中混合合成色素,获得较满意的结果,同时对影响实际样品分析的因素进行了探讨。