TDK conference 2019

The growing population of the world requires continuously increasing quantities of food, that shall be of good quality and safe. This can not be solved without using pesticides. The transport and storage of fruits and vegetables are made safer by using fungicides to inhibit the development of molds during transportation. Nice-looking fruits with longer shelf-life are basic consumer expectations, but it is even more important that molds may produce mycotoxins posing a serious risk to human health.

The most commonly used fungicides for this purpose are imazalil, thiabendazole, and prochloraz, which are applied to the fruits by various methods, for example by dipping or spraying. All pesticides, including these, pose a health risk, and therefore the Maximum Residue Limit (MRL) for products on the market is set by law. However, the MRL is only a comparison value; the effects of the given compound in the food chain may depend on many other factors.

The aim of my research was to assess how well consumers are informed about the surface treatment of citrus fruits and to examine how effective the popular cleaning methods are. I examined consumer awareness through an electronic questionnaire. Based on the results, it can be stated that the vast majority of respondents had some information about the treatment of citrus peel. There is a great variety of methods and ideas for cleaning and using the citrus peel, including meaningful and useful procedures, and quite useless ones.

At the Department of Food Hygiene, an LC-MS / MS method was developed and validated for measuring imazalil, tiabendazole, and prochloraz in various fruits. We examined various commercially available fruits for the three compounds and, based on the results of the questionnaire, we tested the effectiveness of the most popular fruit cleaning methods for removing these three compounds from the surface of the fruits.

Laboratory measurements have shown the use of imazalil, tiabendazole, and prochloraz in certain citrus fruits. The picture is quite complex, which is not surprising since the preservation technologies are different in each manufacturer and distributor. Surprisingly, we also found imazalil in products labeled as organic, with a higher content on banana, lower on lemon and orange (based on the weight of the whole fruit). Fortunately, these values are far below the MRLs for adults.

Experiments to investigate the effectiveness of purification procedures showed that neither purification is complete, and the chemical efficacy of a purification method is not necessarily in proportional to its popularity. That is why consumer information is very important in this topic, to dispel misconceptions and to develop consumer attitudes, the latest research findings should be actively involved.