粮油作物中黄曲霉毒素风险预测预警研究进展

粮油作物中黄曲霉毒素污染严重影响着人和动物的健康。开展粮油作物中黄曲霉毒素产生关键影响因素研究,构建早期风险预测模型,是减少污染发生、保障人类健康和减少经济损失的重要途径。文章在总结黄曲霉毒素在粮油作物中风险发生影响因素的基础上,从黄曲霉毒素易发多发的环节如作物收获期和储藏期讨论了预测模型的研究进展,同时归纳了目前预测模型主要建立方法,包括基于回归、神经网络等方法建立的数据驱动模型和基于黄曲霉毒素产生机制建立的机理模型。通过分析目前的研究,讨论了未来粮油作物中黄曲霉毒素风险预测模型的研究方向和应用场景,为开展我国作物中黄曲霉毒素污染风险早期预测和污染防控研究提供参考。     

我国大陆地区食品中柄曲霉素和黄曲霉毒素B1的污染调查

为了解我国食品中黄曲霉毒素B1（Aflatoxin B1,AFB1）和柄曲霉素（Sterigmatocystin,STC）污染情况,采集自我国大陆地区1137份的食品样品以及室温储存1-2年的米份样品315份,采用高效液相色谱-串联质谱方法分析其中AFB1和STC的含量。检测结果显示食品中AFB1检出率范围为0%-40%,谷物类和谷物基加工品检出率分别为0.2%和7.8%;坚果检出率为8.7%,其中有两份样品中AFB1含量超标,啤酒中AFB1的检出率为0%。STC检出率为12.9%,平均含量为0.39 μg/kg,谷物类、谷物基加工品、坚果和啤酒中检出率分别为2.6%,28.3%,4.3%和0%。相比于所采集的超市和农贸市场样品,室温储存1-2年的米粉样品中AFB1和STC的阳性率均较高,分别为4.4%和84.8%,平均含量为0.84和2.38 μg/kg。     

高效液相色谱-串联质谱法测定花生中的黄曲霉毒素B1

目的建立高效液相色谱-串联质谱法测定花生中黄曲霉毒素B_1含量的分析方法。方法样品经乙腈水溶液提取,三氯甲烷反提取后,正己烷净化,以水(D)和乙腈(A)作为流动相进行梯度洗脱,质谱采用多离子检测模式对黄曲霉毒素B_1的定量离子和定性离子进行检测。结果在0.5～10 ng/mL范围内线性良好(线性方程:Y=8.57×10~3X+312, r0.999),黄曲霉毒素B_1在1、5、10μg/kg 3个水平上进行加标回收试验,平均回收率为93.2%～100.2%,相对标准偏差为2.8%～6.9%,方法检出限为0.1μg/kg。结论该方法经济、快速、准确,适合测定花生中黄曲霉毒素B_1的含量。     

远红外辐照对大米黄曲霉孢子及其产毒能力的影响

以接种黄曲霉孢子的大米为原料,采用远红外辐照杀菌技术,研究了红外辐照对黄曲霉孢子的杀灭效果、生长曲线和产黄曲霉毒素B1(AFB1)能力的影响,同时考察了其对大米的色泽、游离氨基酸、可溶性蛋白等品质的影响。结果表明,远红外对黄曲霉孢子的杀灭效果随着辐照温度的升高和时间的延长而显著增强。当大米含水率为30%时,辐照温度115℃处理5 min,黄曲霉对数降低值(lgS)为2.96±0.28,AFB1总量下降63.09%,单位菌体产毒量下降38.44%;当大米含水率为20%时,lgS为2.04±0.17,AFB1总量下降55.04%,单位菌体产毒量下降22.54%。采用先115℃高温处理5min后70℃保温5 min,大米黄曲霉lgS3.87,L、b、△E和游离氨基酸含量均无显著性差异,可溶性蛋白含量随着处理时间的延长逐渐降低。     

浓香花生油生产技术实践

对浓香花生油生产技术实践进行了介绍,包括炒籽压榨制油、蒸炒压榨制油工艺及低温水化脱胶、低温无水脱胶工艺,并对浓香花生油调香、黄曲霉毒素的脱除、劣质花生及花生油的处理及花生油中矿物油含量的控制等问题进行讨论,为工业化生产安全优质的浓香花生油提供参考。     

国外花生研究进展

介绍国外对花生的加工处理如烘烤和油炸,及对花生壳的利用。分析了对花生凝集素的研究,特别是控制黄曲霉毒素以实现花生的贮藏与加工的安全。     

组合实验设计用于黄曲霉毒素污染控制的研究

为控制黄曲霉毒素主要产生菌寄生曲霉 AS3.4407在粮食储藏环境中的产毒污染,采用组合实验设计策略,考察了五个模拟环境因子对菌株产毒的影响。首先,利用 Plack-ett-Burman 试验筛选出三个对毒素产量影响显著的因子(转速、温度、pH),在此基础上,采用CCD 实验设计法(Central Composite Design,CCD)研究了这三个因子对寄生曲霉 AS3.4407产毒影响的交互作用,并根据毒素曲面方程和二次多项回归方程得到该菌的最低产毒条件。在环境通风良好(转速240rpm),储藏温度较低(18℃),pH 为弱碱性(pH8)条件下,寄生曲霉AS3.4407产毒量最低,验证试验证实了该方程的预测值与实际值之间具有较好的拟合度。为粮库采取相应措施,改变储藏环境条件以降低毒素污染提供了很好依据。     

Stabilization of the Single-Chain Fragment Variable by an Interdomain Disulfide Bond and Its Effect on Antibody Affinity

The interdomain instability of single-chain fragment variable (scFv) might result in intermolecular aggregation and loss of function. In the present study, we stabilized H4—an anti-aflatoxin B₁ (AFB₁) scFv—with an interdomain disulfide bond and studied the effect of the disulfide bond on antibody affinity. With homology modeling and molecular docking, we designed a scFv containing an interdomain disulfide bond between the residues H44 and L100. The stability of scFv (H4) increased from a GdnHCl₅₀ of 2.4 M to 4.2 M after addition of the H44-L100 disulfide bond. Size exclusion chromatography revealed that the scFv (H44-L100) mutant existed primarily as a monomer, and no aggregates were detected. An affinity assay indicated that scFv (H4) and the scFv (H44-L100) mutant had similar IC₅₀ values and affinity to AFB₁. Our results indicate that interdomain disulfide bonds could stabilize scFv without affecting affinity.     

Studies on aflatoxin in rice: Description and evaluation of a new apparatus for the separation of husk from dehulled rice contaminated with aflatoxin

A simple apparatus and method developed for the separation of husk from dehulled (brown) rice contaminated with aflatoxin is described. The performance and efficiency of the apparatus was evaluated by passing a series of dehulled rice and husk mixtures through it. Subsequently the aflatoxin distribution in both rice and husk was determined. The range was 24 to 81% for aflatoxin B₁ and 11 to 76 % for B₂, depending on the rice grain category and variety. The study indicates that the apparatus can be used conveniently to separate husk from aflatoxin-contaminated rice with a minimum hazard to personnel. It is therefore recommended for use particularly in developing countries, where laboratory test mills may not be available.