我国市售酱油氯丙醇污染研究:地区间污染水平的比较

采用稳定性同位素稀释气相质谱法定量测定多组分氯丙醇,调查了我国市售酱油氯丙醇的污染水平。调查分3次进行,所抽查的629份市售酱油产于2003~2004年间,来自我国11个省、市。各地区样品3-氯-1,2-丙二醇(3-MCPD)的检出率均较高,在90%~100%之间,3-MCPD水平在0.003~189 mg/kg之间,几何均数为21.1μg/kg;2-氯-1,3-丙二醇(2-MCPD)的检出率在14.3%~83.8%之间;1,3-二氯-2-丙醇(1,3-DCP)、2,3-二氯-1-丙醇(2,3-DCP)的检出率分别在0%~24%、0~18.9%之间,全部样品的几何均数低于定量限。总体上,我国市售酱油氯丙醇污染水平有明显下降,但以各地有限的抽查样品评价,污染的地区差异明显,来自河南、广西、浙江样品污染水平以及检出率相对较高,而福建、江苏、北京以及上海样品污染水平较低。     

气-质联用测定食品接触用纸制品中氯丙醇的迁移量

建立了气相色谱-质谱联用法(GC-MS)同时检测食品接触用纸制品中1,3-二氯-2-丙醇(1,3-DCP)、2,3-二氯-1-丙醇(2,3-DCP)、2-氯-1,3-丙二醇(2-MCPD)与3-氯-1,2-丙二醇(3-MCPD)四种氯丙醇迁移量的测定方法,食品模拟物包括4%乙酸、10%乙醇,50%乙醇与橄榄油。通过方法优化,四种氯丙醇的方法检出限与定量限分别为2μg/kg与10μg/kg,加标回收率为87.3%～109%,相对标准偏差(RSD)为1.1%～9.5%(n=6)。实验表明,该方法准确度高,重现性好,可满足纸制品中氯丙醇迁移量的检测要求。应用此方法对15批次纸制品进行检测,结果显示,3-MCPD迁移量的检出率与检出水平最高,1,3-DCP与3-MCPD迁移量的检出率分别为33.3%与53.3%,迁移量分别为2.27～12.04μg/kg与2.51～183.32μg/kg,2,3-DCP与2-MCPD迁移量均为未检出;氯丙醇在水基模拟物的迁移水平比橄榄油模拟物的迁移水平高。纸制品中普遍检出1,3-DCP与3-MCPD迁移,其对食品安全的影响需引起关注。     

气相色谱法测定膨化食品虾条中氯丙醇类化合物

建立了检测膨化食品中 3 氯 1,2 丙二醇和 1,3 二氯 2 丙醇含量的方法。采用乙醚索氏提取、甲醇净化 ,再经N ,O 双 (三甲基硅烷 )三氟乙酰胺 (BSTFA)衍生 ,毛细管气相色谱法分离 ,FID作检测器。方法检出限为 0 0 1mg/kg ,回收率 85 %～ 95 %。     

婴幼儿配方奶粉中氯丙醇脂肪酸酯的检测方法优化与污染暴露

目的：采用气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）联用技术,建立同时测定婴幼儿配方奶粉中3-氯-1,2-丙二醇脂肪酸酯（3-monochloropropane-1,2-diol ester,3-MCPDE）、2-氯-l,3-丙二醇脂肪酸酯（2-monochloropropane-1,3-diol ester,2-MCPDE）、1,3-二氯-2-丙醇脂肪酸酯（1,3-dichloropropane-2-ol ester,1,3-DCPE）和2,3-二氯-1-丙醇脂肪酸酯（2,3-dichloropropane-1-ol ester,2,3-DCPE）含量的分析方法,并对市售50 份婴幼儿配方奶粉中4 种氯丙醇脂肪酸酯的污染水平进行调查分析和风险暴露评估。方法：婴幼儿配方奶粉经脂肪提取后,依次通过碱水解、硅藻土固相萃取小柱净化、七氟丁酰基咪唑衍生上机,同位素内标法定量。结果：该方法在20～600 ng/mL范围内线性良好（r2≥0.998 9）,检出限为0.005 mg/kg,定量限为0.015 mg/kg,检出限和定量限均以相应的氯丙醇计。0.03、0.075 mg/kg和0.15 mg/kg水平下的加标回收率在82.2%～113.9%之间,相对标准偏差均不大于8.3%。50 份奶粉样品中,3-MCPDE检出率为100.0%,含量为0.037～0.208 mg/kg,2-MCPDE检出率为42.0%,含量为ND～0.060 mg/kg,1,3-DCPE和2,3-DCPE均未检出。统计不同月龄婴幼儿氯丙醇脂肪酸酯的平均暴露量,0～6 月龄为3.86 μg/kg、6～12 月龄为2.00 μg/kg、12～36 月龄为1.07 μg/kg。结论：该方法操作简便、准确可靠,适合婴幼儿配方奶粉中4 种氯丙醇脂肪酸酯的同时测定。婴幼儿摄入氯丙醇脂肪酸酯的健康风险需引起关注。     

氨基酸源对热反应牛肉香精中氯丙醇形成的影响

采用气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)仪对热反应牛肉香精及其原料中的氯丙醇进行了分析,并通过单因素试验考察了水解植物蛋白(hydrolyzed vegetable protein,HVP)液、酵母浸膏、VB1、牛肉酶解物、半胱氨酸、谷氨酸、牛骨素、甘氨酸和丙氨酸等原料对热反应牛肉香精中3-氯-1,2-丙二醇(3-chloro-1,2-propanediol,3-MCPD)生成的影响。结果发现,4种氯丙醇中3-MCPD是牛肉香精的主要污染物,且牛肉香精原料中都含有一定量的3-MCPD;牛肉香精原料中所检测的各种氨基酸源对3-MCPD的含量均有显著影响。     

Dietary exposure to chloropropanols of secondary school students in Hong Kong

This paper reports levels of 3-monochloropropan-1,2-diol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) in a wide range of food items and estimates their dietary exposure for secondary school students in Hong Kong. Dietary exposure to chloropropanols was estimated using local food consumption data obtained from secondary school students in 2000 and the concentrations of 3-MCPD and 1,3-DCP in food samples taken from the local market. The dietary exposure to 3-MCPD for an average secondary school student consumer was estimated to be 0.063–0.150 µg kg^?1 body weight (bw) day^?1, whilst that for the high consumer was 0.152–0.300 µg kg^?1 bw day^?1. Both estimates fell below the provisional maximum tolerable daily intake of 2 µg kg^?1 bw established by the Joint Expert Committee on Food Additives (JECFA) and amounted to less than 20% of this safety reference value. The dietary exposure to 1,3-DCP for an average secondary school student consumer was estimated to be 0.003–0.019 µg kg^?1 bw day^?1, whilst that for the high consumer was 0.009–0.040 µg kg^?1 bw day^?1. The resulting margins of exposures were of low concern for human health. It could be concluded that both the average and high secondary school student consumers were unlikely to experience major toxicological effects of 3-MCPD and 1,3-DCP.     

油脂中氯丙醇形成机制及控制研究进展

食品中的氯丙醇污染是目前国际上广为关注的食品安全问题之一, 最初在酸水解植物蛋白加工中被检出, 近年来发现氯丙醇及其酯类化合物广泛存在于油脂及其加工品中, 成为危害消费者身体健康的又一隐性因素, 从而引起人们的再次高度关注。本文较为全面地介绍了氯丙醇的定义、分类, 分析了氯丙醇的潜在毒性及在食品中的污染现状, 总结了氯丙醇特别是3-氯-l,2-丙二醇(3-monochloropropanol-l,2-diol, 3-MCPD)的可能形成途径, 并归纳了油脂加工过程中可行的控制方法。     

Thermal degradation of sucralose and its potential in generating chloropropanols in the presence of glycerol

Sucralose, a polychlorinated synthetic high-intensity sweetener is being increasingly used in relatively large amounts in baked products under high temperature environments. This necessitates understanding its thermal decomposition and studying the consequences of hydrogen chloride release from sucralose and its ability to chlorinate various food related ingredients such as glycerol to generate chloropropanols a potentially toxic class of compounds. Studies conducted on the thermal degradation of sucralose under dry heating conditions have indicated that the glycosidic cleavage occurs through the formation of a galactopyranosyl cation contrary to sucrose where fructofuranosyl cation dictates the major breakdown products. Consequently the major product detected was levoglucosenone and its precursor. Subsequent degradation of the two monosaccharide derivatives causes dehydrochlorination and dehydration reactions to produce furan-related products. In addition, pyrolysis of sucralose in the presence of glycerol generated significant amounts of 3-monochloropropanediol and 1,2- and 1,3-dichloropropanols based on the relative intensities of their chromatographic peaks which amounted to 15% of the total chromatographic peak area.     

Effects of yeast stress and pH on 3-monochloropropanediol (3-MCPD)-producing reactions in model dough systems

A major precursor of 3-monochloropropanediol (3-MCPD) in leavened cereal products is glycerol, which is formed as a natural by-product of yeast fermentation. However, yeast metabolism is affected by stresses such as low osmotic pressure from, for example, the incorporation of sugar or salt in the dough recipe. Tests with model doughs have shown that glycerol production was proportional to yeast mass and limited by available sugars, but that high levels of yeast inhibited 3-MCPD formation. The yeast fraction responsible for the inhibition of 3-MCPD in model dough was shown to be the soluble cytosol proteins, and the inhibition mechanism could be explained by the known reactions of 3-MCPD and/or its precursors with ammonia/amino acids (from yeast proteins). Added glucose did not increase the production of glycerol by yeast but it did promote the generation of 3-MCPD in cooked doughs. The latter effect was attributed to the removal of 3-MCPD inhibitors such as ammonia and amino acids by their reactions with added glucose (e.g. Maillard). The thermal generation of organic acids from added glucose also reduced the pH of cooked doughs, so the effect of pH and short-chain organic acids on 3-MCPD generation in dough was measured. There was a good correlation between initial dough pH and the level of 3-MCPD generated. The effect was weaker than that predicted by simple kinetic modelling, suggesting that the involvement of H⁺ and/or the organic acid was catalytic. The results showed that modifications to dough recipes involving the addition of reducing sugars and/or organic acids can have a significant impact on 3-MPCD generation in bakery products.     

Determination of 1,3-dichloropropanol in soy and related sauces by using gas chromatography/mass spectrometry

A gas chromatography/mass spectrometry method for 3-MCPD in foods and food ingredients was modified for the determination of 1,3-DCP in soy and related sauces. The method was validated by using a blank soy sauce. The detection limit, quantitation limit and recoveries were determined, and identities were confirmed by mass spectrometry on the basis of analyses of test portions spiked with 1,3-DCP at 10, 25, 50 and 100 ng g^-1. The spiked test portions were quantitated by using an internal standard calibration curve. For the spiked test portions, the mean internal standard-corrected recovery for 1,3-DCP was 100% with a relative standard deviation of 1.32%. The limits of detection and quantitation were determined as 0.055 and 0.185 ng g^-1, respectively. The method also was compared with a headspace GC/MS method recently developed by the UK's Central Science Laboratory. Results from the method comparison showed that the recoveries for the spiked test portions, as well as the amounts of 1,3-DCP found in the retail products, were comparable.