对热处理玉米食品中的伏马毒素和结合伏马毒素进行分析。

Analysis of heat-processed corn foods for fumonisins and bound fumonisins.

作者信息

Park J W, Scott P M, Lau B P Y, Lewis D A

机构信息

Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario K1A 0L2, Canada.

出版信息

Food Addit Contam. 2004 Dec;21(12):1168-78. doi: 10.1080/02652030400021873.

DOI:10.1080/02652030400021873

PMID:15799562

Abstract

Thirty retail samples of heat-processed corn foods, i.e. corn flakes, corn-based breakfast cereals, tortilla chips and corn chips, were analysed for fumonisins--fumonisin B1 (FB1), fumonisin B2 (FB2) and hydrolysed FB1 (HFB1)--as well as for protein- and total-bound FB1. Bound (hidden) fumonisins cannot be detected by conventional analysis. Improved methods for the determination of bound FB1 were developed. The protein-bound FB1 was extracted with 1% sodium dodecylsulfate (SDS) solution. The SDS, which interfered with high-performance liquid chromatography (HPLC) analysis, was then separated from protein-bound FB1 by complexing with methylene blue followed by solvent extraction and hydrolysis with 2 N KOH. To measure total-bound FB1, the sample itself was hydrolysed with KOH. In both cases, clean-up was accomplished on an OASIS polymeric solid-phase extraction column and the bound fumonisins were determined by HPLC measurement of HFB1. Fourteen of 15 samples of corn flakes and other corn-based breakfast cereals analysed contained detectable levels of FB1 with a mean in positive samples of 67ng g(-1) (13-237 ng g(-1)). Two samples also had detectable levels of FB2 (21-23ng g(-1)). Bound FB1 was found in all samples; the mean protein-bound FB1 measured was 58 ng g(-1) (22-176 ng g(-1)) and the mean total-bound FB1 measured was 106 ng g(-1) (28-418 ng g(-1)), reported as FB1 equivalents after correction for recoveries of HFB1. There was an average of about 1.3 times more FB1 in the bound form compared with extractable FB1, and this was about twice as much as protein-bound FB1. Seven of the 15 samples of alkali-processed corn-based foods, such as tortilla chips and corn chips, contained FB1 and three contained HFB1 with means in measurable positive samples of 78 (48-134) and 29 (13-47) ng g(-1), respectively. Five of these alkali-processed corn foods contained bound FB1; the mean measurable protein-bound FB1 was 42 ng g(-1) (39-46 ng g(-1)) and the mean measurable total-bound FB1 was 100 ng g(-1) (54-209 ng g(-1)). HFB1 derived from bound FB1 in selected samples was confirmed by HPLC with mass spectrometry (MS).

摘要

对30份经过热处理的玉米食品零售样品，即玉米片、玉米早餐谷物、玉米饼薯片和玉米片，进行了伏马毒素分析，包括伏马毒素B1（FB1）、伏马毒素B2（FB2）和水解FB1（HFB1），以及蛋白质结合型和总结合型FB1。传统分析方法无法检测到结合态（隐藏的）伏马毒素。因此开发了改进的结合态FB1测定方法。用1%十二烷基硫酸钠（SDS）溶液提取蛋白质结合型FB1。然后，通过与亚甲蓝络合、溶剂萃取以及用2N氢氧化钾水解，将干扰高效液相色谱（HPLC）分析的SDS与蛋白质结合型FB1分离。为测定总结合型FB1，用氢氧化钾对样品本身进行水解。在这两种情况下，均通过OASIS聚合物固相萃取柱进行净化，并通过对HFB1的HPLC测定来确定结合态伏马毒素。在分析的15份玉米片和其他玉米早餐谷物样品中，有14份含有可检测水平的FB1，阳性样品中的平均含量为67ng g⁻¹（13 - 237 ng g⁻¹）。两份样品还含有可检测水平的FB2（21 - 23ng g⁻¹）。所有样品中均发现了结合型FB1；测得的蛋白质结合型FB1平均含量为58 ng g⁻¹（22 - 176 ng g⁻¹），测得的总结合型FB1平均含量为106 ng g⁻¹（28 - 418 ng g⁻¹），以校正HFB1回收率后的FB1当量表示。结合态FB1中的FB1平均含量约为可提取FB1的1.3倍，约为蛋白质结合型FB1的两倍。在15份碱处理玉米基食品样品中，如玉米饼薯片和玉米片，有7份含有FB1，3份含有HFB1，可测量阳性样品中的平均含量分别为78（48 - 134）和29（13 - 47）ng g⁻¹。这些碱处理玉米食品中有5份含有结合型FB1；测得的可测量蛋白质结合型FB1平均含量为42 ng g⁻¹（39 - 46 ng g⁻¹），测得的可测量总结合型FB1平均含量为100 ng g⁻¹（54 - 209 ng g⁻¹）。通过HPLC与质谱联用（MS）对选定样品中由结合型FB1衍生的HFB1进行了确证。