Detection of volatile indicator compounds for biological contamination and deterioration of food

检测食品生物污染和变质的挥发性指示剂化合物

• 批准号: BB/E023967/1
• 负责人: John Pickett
• 金额: $ 11.55万
• 依托单位: Rothamsted Research
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FE023967%2F1
• 关键词: Detection; volatile; indicator; compounds; biological

When fruit deteriorates because of damage, insect infestation or fungal and bacterial infections, it produces characteristic odour chemicals that are not produced by healthy fruit. If those chemicals were detectable at an early stage of deterioration, before there were any visible signs, it would save a lot of wastage by growers, distributors and retailers. Although the means of detecting traces of chemicals in the air exist there is no existing method for identifying which chemicals are specifically associated with the early stages of deterioration. They are likely to be present in tiny amounts as part of a complex mixture of chemicals, many of which will be present in relatively large quantities. This project will provide a means of identifying those chemicals, using the sensitivity and discriminatory power of insect olfaction, so that their detection can be used to monitor for the early deterioration of fruit. The methods will also be applicable to many other foods and situations. The Mediterranean fruit fly lays its eggs inside healthy fruit, oranges in this project, where the larvae will subsequently develop with no visible external signs of their presence for some time. Honeybees, that we know can respond to fruit and infection related chemicals, will be trained to recognise the specific chemicals associated with such an infestation. This will be done by giving the bees a sugar reward, to which they respond by extending their proboscis or tongue, at the same time as exposing them to the odours from fruit containing the insect larvae and no reward when exposed to the odours of healthy fruit or damaged but uninfested fruit. After training they will extend their proboscis in response to the odour from the contaminated orange even without a reward. The odours from insect-infested oranges will also be collected by adsorption onto a porous polymer and elution with a solvent to provide a solution of the chemicals involved. This will contain many additional chemicals but these will be separated by gas chromatography into the separate component chemicals which will be blown, sequentially but one at a time, across the antennae of a trained honeybee. When the bee is exposed to the particular chemical(s) that it uses to discriminate between infested and healthy fruit it will extend its proboscis, a response that is very easy to observe and record. These particular chemicals will then be identified by standard analytical methods including mass spectrometry and nuclear magnetic resonance spectroscopy. As a check on the methods, samples of the chemicals will be obtained and used to train more honeybees which will then be exposed to infested and uninfested fruit to confirm that they are the correct chemicals. Portable mass spectrometers will then be programmed to look for these chemicals in the odours from fruit, both in the laboratory and in the processing and distribution centres.

当水果因损坏、虫害或真菌和细菌感染而变质时，它会产生健康水果不会产生的特殊气味化学物质。如果在作物变质的早期阶段，在出现任何明显迹象之前就能检测到这些化学物质，那么种植者、分销商和零售商就能节省大量的浪费。虽然存在检测空气中痕量化学物质的手段，但没有现有的方法来确定哪些化学物质与变质的早期阶段具体有关。它们很可能以微量的形式出现在复杂的化学混合物中，而其中许多会以相对大量的形式出现。这个项目将提供一种方法，利用昆虫嗅觉的敏感性和辨别能力来识别这些化学物质，以便它们的检测可以用来监测水果的早期变质。这些方法也适用于许多其他食品和情况。在这个项目中，地中海果蝇在健康的水果橙子中产卵，幼虫随后会在一段时间内没有明显的外部迹象。我们知道蜜蜂可以对水果和感染相关的化学物质做出反应，它们将被训练识别与这种感染相关的特定化学物质。这将通过给蜜蜂糖奖励来实现，蜜蜂通过伸出它们的喙或舌头来回应，同时让它们暴露在含有昆虫幼虫的水果的气味中，而让它们暴露在健康水果或受损但未感染的水果的气味中则没有奖励。经过训练，即使没有奖励，它们也会对被污染的橙子发出的气味做出反应，伸出它们的长鼻。受昆虫侵袭的橙子的气味也将通过吸附在多孔聚合物上，并用溶剂洗脱，以提供所涉及的化学物质的溶液来收集。这将包含许多额外的化学物质，但这些化学物质将被气相色谱法分离成单独的化学成分，这些化学成分将被依次吹过训练有素的蜜蜂的触角，但每次只吹一种。当蜜蜂接触到它用来区分受感染水果和健康水果的特定化学物质时，它会伸出它的喙，这种反应很容易观察和记录。这些特殊的化学物质将通过包括质谱和核磁共振光谱在内的标准分析方法进行鉴定。作为对这些方法的检查，将获得化学品样本并用于训练更多的蜜蜂，然后将它们暴露于受感染和未受感染的水果中，以确认它们是正确的化学品。然后，便携式质谱仪将在实验室以及加工和配送中心的水果气味中寻找这些化学物质。

项目成果

Aspects of insect chemical ecology: exploitation of reception and detection as tools for deception of pests and beneficial insects

昆虫化学生态学方面：利用接收和检测作为欺骗害虫和益虫的工具

• DOI: 10.1111/j.1365-3032.2011.00828.x
• 发表时间: 2012
• 期刊: Physiological Entomology
• 影响因子: 1.5
• 作者: PICKETT J