玉米中伏马毒素B1、B2间接竞争酶联免疫吸附方法的建立

基于伏马毒素B1(fumonisin B1,FB1)单克隆抗体建立了间接竞争酶联免疫吸附法(indirect competitive enzyme linked immunosorbent assay,ic-ELISA),用于玉米中伏马毒素的初步筛查。该方法优化了抗原包被浓度和单抗体稀释倍数、抗原包被条件、酶标二抗稀释倍数、底物作用时间。结果显示,线性检测范围为1.41～54.2ng/m L,最低检测限为24.5μg/kg,实测玉米样品加标回收率为89.36%～108.54%。交叉反应结果显示,与伏马毒素B2(fumonisin B2,FB2)交叉反应率为129.88%,与其他真菌毒素交叉反应均小于10%,该ic-ELISA方法可对玉米样品中的FB1与FB2总量进行初筛。     

单克隆免疫亲和柱-高效液相色谱法测定玉米中伏马毒素B1、B2

研究了单克隆免疫亲和柱 -高效液相色谱法测定玉米中伏马毒素B1、B2 的方法。玉米样品经甲醇 -水(4∶1)提取 ,提取液通过FumoniTest免疫亲和柱净化 ,净化液经柱前衍生、SpherisorbC18色谱柱分离、荧光检测器检测、外标法定量。对添加不同含量的伏马毒素B1、B2 进行 5次重复实验 ,得B1的平均回收率为 82 .3%～88.7% ,B2 为 74.9%～ 81.6 %。B1的变异系数 (CV)为 4.9%～ 6 .3% ,B2 为 5 .8%～ 7.2 %。检测低限B1为0 .0 2 0mg/kg,B2 为 0 .0 40mg/kg。     

单克隆免疫亲和柱—高效液相色谱法测定酱油中伏马毒素B1、B2

研究了单克隆免疫亲和柱－高效液相色谱法测定酱油中伏马毒素B1、B2的方法。样品经离心和玻璃纤维滤纸过滤后,通过FumoniTest免疫亲和柱净化,净化液经柱前衍生,Spherisorb C18色谱柱分离,荧光检测器检测,外标法定量。对添加不同含量水平的伏马毒素B1、B2,5次重复实验的平均回收率为B1 84．6％－89．2％,B2 60．3％－69．5％。变异系数（CV）为B1 5．5％－7．8％,B2 6．2％－9．3％。检测低限为B1 0．01mg/kg,B2 0.02mg/kg。     

单克隆免疫亲和柱—高效液相色谱法测定啤酒中伏马毒素B1、B2

研究了单克隆免疫亲和柱－高效液相色谱法测定啤酒中伏马毒素B1、B2的方法。啤酒样品经脱气后,通过FumoniTest免疫亲和柱净化,净化液经柱前衍生,Spherisorb C18色谱柱分离,荧光检测器检测,外标法定量。对添加不同含量水平的伏马毒素B1、B2,5次重复实验的平均回收率为B1 86．1％－93．4％,B2 71．6％－82．0％。变异系数（CV）为B1 4．8％－7．2％,B2 6．3％－8．9％。检测低限为B1 0．005mg/kg,B2 0.01mg/kg。     

玉米及其制品中伏马菌素的去除方法

伏马茵素分布广泛且毒性较大,丢弃受伏马菌素污染的玉米将造成巨大的经济损失,因此降解和去除玉米及其制品中伏马菌素的技术和方法日益受到人们的重视.介绍了伏马菌素的性质以及伏马菌素污染食品的情况,对去除伏马菌素的方法,如物理法、化学法、生物法进行总结和阐述,并对去除和降解伏马菌素的前景进行展望.     

单克隆免疫亲和柱－高效液相色谱法测定啤酒中伏马毒素B 1、B 2

研究了单克隆免疫亲和柱－高效液相色谱法测定啤酒中伏马毒素B1、B2的方法。啤酒样品经脱气后,通过FumoniTest免疫亲和柱净化,净化液经柱前衍生,SpherisorbC18色谱柱分离,荧光检测器检测,外标法定量。对添加不同含量水平的伏马毒素B1、B2,5次重复实验的平均回收率为B186.1％～93.4％,B271.6％～82.0％。变异系数(CV)为B14.8％～7.2％,B26.3％～8.9％。检测低限为B10.005mg/kg,B20.01mg/kg。     

液相色谱串联质谱法测定玉米粉中伏马毒素B_1的不确定度评定

采用液相色谱-串联质谱法对玉米粉中伏马毒素B_1进行不确定度评定。通过整个过程测定,建立不确定度评定的数学模型,确定影响不确定度的主要来源,对各不确定度分量进行合成和扩展,最终建立了液相色谱_串联质谱法测定玉米粉中伏马毒素B_1的不确定度评定方法。结果表明,影响玉米粉中伏马毒素B_1测定的主要来源为溶液测定,样品定容,提取回收率,测定重复性和称样量,其测定结果为(3.542±0.779)μg/kg,k=2。按引入的不确定度的贡献大小排序,依次为溶液测定,样品定容,提取回收率,测定重复性和称样量,溶液测定引入的不确定度贡献最大。     

QuEChERS-超高效液相色谱-串联质谱法测定玉米油中伏马毒素B1、B2、B3

目的建立QuEChERS-超高效液相色谱-串联质谱法快速测定玉米油中伏马毒素B_1、B_2和B_3的分析方法。方法样品经酸化的乙腈水溶液混合振荡提取,然后进行盐析液体分配,通过QuEChERS净化柱净化,以乙腈和水为流动相, C_(18)色谱柱(2.1 mm×100 mm, 2.7μm)进行分离,多反应监测模式检测,采用基质匹配标准曲线进行定量分析。结果 3种伏马毒素在0.5～100.0μg/L线性范围内线性关系良好,相关系数r~20.99,检出限和定量限分别为0.12～0.70μg/kg和0.42～2.40μg/kg。在3个添加水平下, 3种伏马毒素的平均加标回收率为83.2%～108.0%(n=6),相对标准偏差为1.9%～4.6%。结论本方法操作简便、检测成本低、定量准确,适于玉米油样品中伏马毒素的快速检测。     

高效液相色谱法检测玉米中的伏马毒素B_1和B_2

采用柱前衍生,高效液相色谱分离,荧光分光光度法对玉米中伏马毒素B1和B2进行了定量测定,其线性范围分别为1.04～16.67ng(FB1)和1.67～26.67ng(FB2),检测限分别为0.037和0.028mg/kg。以该方法对加标玉米中的伏马毒素进行回收率测定,加标水平为0.1～2mg/kg时,FB1和FB2的平均回收率分别为80.1%和82.0%。     

二氧化氯对霉变玉米黄曲霉毒素B1脱毒效果的研究

霉变染有黄曲霉毒B1（AFB1）的玉米,用低浓度（250μg/ml）二氧化氯浸泡30－60min,能有效地解除AFB1的毒性。比较了二氧化氯作用时间及不同产地产品脱毒效果的差异,对二氧化氯的解毒功效及其使用安全性也作了探讨。     

Fumonisin B1, fumonisin B2, zearalenone and ochratoxin A contamination of maize in Croatia

Mycotoxins are products of moulds that frequently contaminate maize. In this study the presence of mycotoxins fumonisin B₁ (FB₁), fumonisin B₂ (FB₂), zearalenone (ZEA) and ochratoxin A (OTA) was determined in 49 maize grain samples collected in autumn 2002. The most frequent finding was that of FB₁(100%), followed by ZEA (84%) and OTA (39%), while FB₂ was found only in three samples. The co-occurrence of two and three mycotoxins was found in 55 and 37% of samples, respectively. The concentrations (mean ± SD) of FB₁, ZEA and OTA in positive samples were 459.8 ± 310.7, 3.84 ± 6.68 and 1.47 ± 0.38 µg kg^-1, respectively, and the concentrations of FB₂ in three positive samples were 68.4, 109.2 and 3084.0 µg kg^-1. Although such low concentrations of mycotoxins are not a significant source of exposure in countries with a European diet, a few samples with extreme values indicate that thorough control is needed.     

Use of a bio-wipe kit to detect fumonisin B1 in faecal materials

Fusarium toxins with reference to fumonisin B1 (FB1) have long been regarded as contaminants of maize and maize-based related products. However, when consumed they can cause intoxication, especially in humans. Therefore, effective quantitative methods for assessing the dietary exposure of this toxic fungal metabolite are required. The objective of this investigation was to evaluate the effect on the use of a bio-wipe kit, which is a faecal material collection kit, to detect the presence of FB1. Faecal materials were collected from a rural farming community in Gauteng Province, South Africa. In total, 200 samples of faecal material were analysed for Fusarium species using a serial dilution method, while FB1 was further analysed and quantified by reversed-phase TLC and HPLC. The study showed the presence of 11 different Fusarium species grown on potato dextrose agar culture medium of which F. verticillioides and F. proliferatum, producers of FB1, and F. oxysporum were the dominant species. Fumonisin B1 was recorded at an incidence rate of 65% of the total using TLC. Results from HPLC showed that 84% were positive at different ranges of concentration for FB1. This study supports the use of a bio-wipe as a rapid method to determine human exposure to FB1.     

Determination of the mycotoxin fumonisin B1 in maize by reversed-phase thin-layer chromatography: a collaborative study

A simple and cost-effective method using thin-layer chromatography for the determination of the mycotoxin fumonisin B₁ in maize is described. The analytical method consisted of the extraction of ground maize by shaking with methanol/water (75:25) for 60 min and clean-up of the resultant extract by means of strong anion exchange solid-phase extraction. The purified residue, formed by evaporation of the elution solvent, was reacted with fluorescamine and the fumonisin B₁-derivative was separated by reversed-phase thin-layer chromatography using a developing solution of methanol/aqueous 4% potassium chloride (70:30). The derivatized FB₁ was readily visualized as a greenish-yellow spot under long wavelength ultraviolet light and quantified by visual comparison with a set of similarly derivatized standards in the range 20-300 ng FB₁ spotted on plate. Based on visual comparison, levels down to 0.5 mg kg^-1 were successfully estimated. The method was collaboratively studied in 14 laboratories using four duplicate maize meal samples (including a blank) and a spiked sample for determination of recovery. No significant difference was observed between mean FB₁ levels by high-performance liquid chromatography or thin-layer chromatography. Based on within-laboratory relative standard deviations of 27.1-41.7% and between-laboratory relative standard deviations of 35.0-63.3%, the method can be considered semiquantitative. The mean recovery achieved by participants at a spiking level of 2.00 mg kg^-1 was 74.5%.     

Effects of previous storage history, hybrid, and drying method on the storability of maize grain (corn)

Maize grain (corn) from three harvest years (1986, 1991, and 1992) was harvested, dried, and stored in small bins. Samples taken at harvest and samples taken after various periods of bin storage (up to 77 months) were subjected to accelerated storage tests for measurement of carbon dioxide (CO₂) evolution. The initial (t < 72 h) slopes (SLOPE72) of CO₂ evolution rate curves were related to storability (r = 0.82), as measured by cumulative CO₂ evolution at 200 h. SLOPE72 (a faster test method than cumulative evolution) was subsequently used to evaluate the effects of the following factors on storability: (1) hybrid, (2) drying method, and (3) previous storage history. Differences in storability, attributable to hybrid, were significant both at harvest and after periods of bin storage. One extremely unusual growing year (severe drought stress) affected the otherwise consistent storability ranking among hybrids. Maize grain dried by high-temperature (95 °C) batch crossflow drying had significantly lower storability (i.e. greater SLOPE72) than did the same hybrids dried by low-temperature (ambient air) drying. Previous storage history (moisture content and duration) affected subsequent storability. Storage for longer periods, given the same moisture content, resulted in lower subsequent storability, and storage at higher moisture content, given the same time period, also resulted in lower subsequent storability.     

低温干燥冷藏调湿多功能储粮系统及特性分析

干燥是粮食行业的主要耗能环节,目前粮食干燥多采用烘干机或烘干塔,热损失大、能耗高,有些以煤炭作为热源,环境污染严重。另外,粮食长期储藏过程中易发生霉变和虫害,同时长期储藏会导致粮食水分过低影响粮食加工品质。实现粮食高品质、低能耗干燥及长期安全储藏和保证出库粮食的品质具有重大意义,因此提出了一种低温干燥冷藏调湿多功能储粮系统,并基于该系统开发了具有低温干燥模式、低温冷藏模式和加湿调质模式的设备,可实现“一站式”储粮,使储粮全程自动化控制。通过实验测试,结果表明,三种工作模式下,机组出风参数均满足设计要求。对玉米和萝卜进行了初步干燥实验,玉米的平均干燥速度约1.1%/h、萝卜干燥平均干燥速度2.9%/h左右。通过对系统进行能耗分析可知,本机组与烘干机相比可节能19.4%左右,与冷凝去湿干燥机相比可节能51.7%左右。该设备的驱动能源为电能,环境友好,便于实现粮库的智能化建设,市场应用前景广阔。     

The influence of local factors on the prediction of fumonisin contamination in maize

BACKGROUND: Contamination by mycotoxins is a major concern to the maize industry in north‐east Italy where maize grain is often spoiled by Fusarium spp. In this work, fumonisins, deoxynivalenol and zearalenone were determined and an artificial neural network (ANN) model suitable for predicting mycotoxin contamination of maize at harvest time was developed. RESULTS: The occurrence of deoxynivalenol and zearalenone was very limited, while fumonisins concentration ranged from 163 and to 3663 µg kg^?1 in 2007, and from 333 to 11473 µg kg^?1 in 2008. Statistical data analysis of factors affecting fumonisins concentration revealed that irrigation, chemical treatment against the European corn borer and harvest date significantly affected the level of contamination (P < 0.05), although the relevance of the factors was different in 2007 and 2008. The neural network approach showed a significant correlation between ascertained values and predictions based on agronomic data. CONCLUSION: This is the first time that an artificial neural network has been used to predict fumonisin accumulation in maize: the prediction has been shown to have the potential for the development of a new approach for the rapid cataloging of grain lots. Copyright © 2012 Society of Chemical Industry