Residues and Contaminants in Processed Foods, Mushrooms, Cereals and Potatoes, 2016
Summary of Residue Findings in Products from Conventional Production
Ein Bericht aus unserem Laboralltag
Ellen Scherbaum, Kathi Hacker und Alexander Lemke
Investigatory Background
The focus of pesticide residue analyses is usually on fresh fruit and vegetables. However, processed commodities such as deep-frozen products, dried vegetables and fruits, preserved foods, and juices are also consumed in large amounts and must, therefore, also be analyzed. The further processing of foods often leads to a reduction in residues; the judgment of whether a product has met the EU-wide legal MRL must therefore take this effect of processing into consideration.
Info Box
Consideration of Processing Factors
As a rule, Regulation (EC) No. 396/2005 regulates the maximum authorized amount of pesticide residues for unprocessed foods. The level of residues from pesticides/active substances in and on unprocessed foods can change as a result of processing procedures, however. Thus, when making a legal judgment regarding the acceptability of the detected quantity of residues from active substances in processed foods, Regulation (EC) No. 396/2005 stipulates that these changes must be considered. These would include the procedures used in making dried fruit, preserves, juices or wine. For example, if not sour cherries themselves, but preserves made from the cherries were being analyzed, a processing factor would have to be considered, because the process of making preserves usually results in a reduction of residues. That means the amount of residues detected in the total product (cherries plus infusion) is referred to that of the raw, unprocessed product (cherries), and this theoretically determined amount is compared to the valid MRL for the unprocessed product. In contrast, the process of drying fruits concentrates the active substances in the fruit; therefore, the amount of residues in the original product is lower than that in the dried fruit.
Summary
Of all the analyzed conventional samples, in 413 (97%) residues were detected, with a total of 172 different active substances. The MRL was exceeded in 99 of the 413 samples (24%), a rate that is slightly lower than that of the previous year (27%); see Table 1. The cause for this high rate in the last two years is the expansion of the spectrum of investigated substances to include polar pesticides and the high number of MRL exceedances for the substance chlorate. When excluding the samples with high levels of chlorate from the calculation, the percentage of MRL exceedances lies at 9.4%, for 39 samples.
Number of Samples |
413
|
---|---|
Samples with residues |
402 |
Samples with residues over the MRL* |
99 |
Average quantity of pesticides |
2.1 mg/kg |
Average quantity of pesticides excluding fosetyl**, bromide, surface treatment substances |
0.41 mg/kg
|
Average number of substances per sample |
4.6
|
The level of pesticide residues differed, sometimes greatly, by type of commodity. The results of the residue analyses are presented in Tables 2 and 3, differentiated by type of sample.
Sample Type | No. of Samples |
With Residues
|
With Multiple-Residues
|
Samples
>MRL* |
No. Findings
>MRL* |
Substances > MRL* |
---|---|---|---|---|---|---|
Fats, Oils |
17 |
11 (65%) |
8 (47%) |
|
|
|
Cereals |
23 |
19 (83%) |
13 (57%) |
5 (22%) |
5 |
Glyphosate (4x); Dichlorvos |
Cereal products |
8 |
8 (100%) |
7 (88%) |
|
|
|
Legumes, oil seeds, |
32 |
29 (91%) |
65 (98%) |
4 (13%) |
4 |
Glyphosate; Fosetyl, sum; |
Potatoes and |
65 |
63 (97%) |
17 (53%) |
8 (12%) |
8 |
Chlorate (2x); Fosetyl, sum; |
Vegetable |
66 |
66 (100%) |
54 (83%) |
47 (71%) |
86 |
Chlorate (38x); |
Mushrooms |
56 |
50 (89%) |
31 (55%) |
5 (8,9%) |
6 |
Chlorate (3x); Chlorpropham; |
Mushroom |
16 |
16 (100%) |
16 (100%) |
5 (31%) |
5 |
Chlorate (4x); Nicotine |
Fruit products |
71 |
67 (94%) |
62 (87%) |
12 (17%) |
13 |
Carbofuran, sum (3x); |
Non-alcoholic drinks |
38 |
35 (92%) |
30 (79%) |
8 (21%) |
8 |
Chlorate (8x) |
Beers and raw materials |
3* |
3 |
3 |
|
|
|
Wine and wine products |
27 |
27 (100%) |
27 (100%) |
|
|
|
Nutritional |
2 |
1 |
1 |
1 |
11 |
Chlorate; Profenofos; Acetamiprid; |
Baby food |
4 |
4 |
0 |
4 |
4 |
Fosetyl, sum (4x) |
Other |
3 |
3 |
3 |
|
|
|
TOTAL | 413 | 402 (97 %) | 337 (78 %) | 99 (24 %) | 150 | - |
Sample Type |
No. of Samples
|
With Residues
|
Ave. no. Substances per Sample
|
Ave. Quantity (mg/kg)*
|
Comments |
---|---|---|---|---|---|
Fats, Oils |
17 |
11 (65%) |
1.6 |
0.008 |
|
Cereals |
23 |
19 (83%) |
2 |
0.1 |
|
Cereal products |
8 |
8 (100%) |
4.4 |
0.34 |
|
Legumes, oil seeds, nuts, soy |
32 |
29 (91%) |
1.9 |
0.24 |
|
Potatoes and |
65 |
63 (97%) |
3,. |
0.8 |
|
Vegetable |
66 |
66 (100%) |
6.9 |
0.77 |
|
Mushrooms |
56 |
50 (89%) |
1.9 |
0.11 |
|
Mushroom products |
16 |
16 (100%) |
3.6 |
0.31 |
|
Fruit products |
71 |
67 (94%) |
8.1 |
0.28 |
|
Non-alcoholic drinks |
38 |
35 (92%) |
4 |
0.056 |
|
Beers and raw materials |
3* |
3 |
5 |
5.3 |
3 samples of hops |
Wine and wine products |
27 |
27 (100%) |
7.5 |
0.13 |
|
Nutritional |
2 |
1 |
9.5 |
4.4 |
1 sample of moringa |
Baby food |
4 |
4 |
1 |
0 |
|
Other |
3 |
3 |
2.5 |
0.02 |
|
TOTAL | 413 | 402 (97 %) | 4.6 | 0.41 | - |
Detailed prensentation of selected topics
Chlorate
Since 2014 the rate of MRL exceedance has become significantly higher than in previous years. This is mainly due to chlorate, which was not previously analyzed, or only in individual cases. A total of 61 of the 413 samples exceeded the MRL of 0.01 mg/kg for chlo-rate. Chlorate residues in plant-based foods can be caused by factors other than the application of herbicides (an unlikely source, since this use has already been banned EU-wide for a long time). These include:
- chlorinated water used for irrigating or watering gardens
- chlorinated water used for irrigating or watering gardens
- disinfection measures using chlorine-containing processing water.
This issue was already extensively presented in 2014 and 2015 in three Internet articles (see also Internet reports under www.cvuas.de):
- Chlorate Residues in Plant-Based Food: Origin Unknown (11 March, 2014)
- Chlorate Residues in Carrots Traced to Chlorinated Water Used in Post-Harvest Treatment (11 March, 2014)
- Chlorate Residues in Plant-Based Food: an Update (9 April, 2015).
Among the processed food, mushrooms, cereals and potatoes evaluated in 2016, processed vegetables and fruit were most often to be found with residues of chlorate that exceeded the MRL of 0.01 mg/kg. A summary of these findings is presented in Table 4. The highest amounts of chlorate detected in processed fruit and vegetables, mushrooms, cereals and potato samples from conven-tional production are depicted in Table 5.
Info Box
Chlorate
Chlorates are effective as both herbicides and biocides. Since 2008, however, chlorate is no longer authorized for use as a pesticide in the EU. Sodium chlorate may also no longer be used in biocide products.
The definition for „pesticide residues“ in Regulation (EC) No. 396/2005 also encompasses residues from pesticide substances in food (including substances no longer authorized) that have pathways other than from the use of plant protectors (so-called dual-use substances). Chlorate, as a substance that is no longer authorized, is thereby covered by the EU-wide valid default MRL of 0.01 mg/kg, in accordance with Reg. (EC) No. 396/2005.
The presence of chlorate in food can result not only from its use as a pesticide, but also due to environmental pollution (contaminated rain- or irrigation water and soil), or as a residual of food production techniques, including methods used in farming, processing, preparation, or treatment. The application of biocides, from which chlorate can result, is another possible source of contamination. In general, chlorate can be formed as a by-product of the disinfection of drinking/ industrial water with chlorine gas, hypochlorite, or chlorine dioxide. However, no limit value for chlorate in drinking water has been established by the drinking water ordinance.
Chlorate inhibits, reversibly, the intake of iodine into the thyroid gland and can cause unwanted health effects, especially in sensitive people such as children, pregnant women, or people with thyroid dysfunction. In addition to affecting thyroid function, chlorate can also damage the erythrocytes (formation of methaemoglobin, haemolysis).
The member states are carrying out a monitoring program to determine the degree of food and drinking water contamination, in order to provide data for a toxicological evaluation by the European Food Safety Authority (EFSA). Specific residue MRLs will then be established based on this information.
No. of Samples
|
Chlorate > MRL
|
|
---|---|---|
Vegetable products, excluding frozen |
15 |
1 (7 %) |
Bell peppers, dried |
1 |
1 |
Frozen vegetables |
51 |
37 (73 %) |
Brussels sprouts, frozen |
10 |
9 |
Spinach, frozen |
2 |
1 |
Chives, frozen |
4 |
3 |
Parsley, frozen |
3 |
2 |
Broccoli, frozen |
6 |
5 |
Carrots, frozen |
1 |
1 |
Peas, frozen |
9 |
6 |
Green beans, frozen |
11 |
8 |
Parisian carrots, frozen |
2 |
2 |
Frozen fruit |
47 |
2 (4.3 %) |
Strawberries, frozen |
3 |
1 |
Blueberries, frozen |
2 |
1 |
Fruit products, excluding frozen |
25 |
3 (12 %) |
Papaya, dried |
1 |
1 |
Plums, dried |
3 |
2 |
Mushrooms and Mushroom products |
72 |
7 (9.7 %) |
White button mushrooms |
20 |
1 |
Wild mushrooms |
23 |
2 |
White button mushrooms, frozen |
4 |
3 |
Wild mushrooms, frozen |
5 |
1 |
Other |
203 |
11 (5.4 %) |
Non-alcoholic drinks |
38 |
8 |
Nutritional supplements |
2 |
1 |
Potatoes and potato products |
65 |
2 |
Type of food | Origin |
Substance
|
Quantity (mg/kg)
|
---|---|---|---|
Chives, frozen |
Unknown |
Chlorate |
3.7 |
Cultured mushrooms |
Poland |
Chlorate |
1.1 |
Bell peppers, dried |
China |
Chlorate |
0.42 |
Broccoli, frozen |
Unknown |
Chlorate |
0.28 |
Chanterelles, frozen |
Unknown |
Chlorate |
0.19 |
A comparison of the chlorate findings in fresh and processed fruits and vegetables is presented in Illustration 1. A notable difference between the fruits and vegetables in terms of the rate of violations can be seen in both categories. This hints at varying modes of entry.
Illustration 1: Chlorate findings in fresh and processed fruit and vegetables (CVUAS 2015, 2016)
Especially eye catching is the rate of 71% for pesticide exceedances among the vegetable products, the majority of cases concerning chlorate. Grape leaves and so-called “super foods” were notable among the vegetable products in 2016.
Grape Leaves
Grape leaves stuffed with a variety of fillings are a popular, widespread dish in Southern European and Oriental cuisine. Since different pesticides are used in the cultivation of wine and table grapes, residues are also expected to be found in grape leaves.
Grape leaves are a side-product of grape production; they aren’t normally grown alone, as an independent culture. That means very few special pesticide MRLs for grape leaves have been applied for. As a result, the default MRLs for grape leaves are mostly very low, set at the lower limit of the analytical of determination. The producers of grape leaves could apply for higher MRLs, but the preparation of the necessary database, obtained via the carrying out of residue analyses, is complex and expensive. In view of the much lower consumption rate of grape leaves compared to that of table grapes, which have to some degree much higher MRLs, an exceedance of the MRL for grape leaves would not be expected to harm the consumer. Nevertheless, the existing, legally binding MRLs are to be adhered to.
Grape leaves from Turkey have been conspicuous in the last several years for their multiple exceedances of the legal MRL. In 2014, therefore, greater control measures were taken on imported Turkish grape leaves, in accordance with Regulation (EC) No. 669/2009.
Nevertheless, in 2016 MRL exceedances were detected anew for grape leaves marinated in brine, often with exceedances of more than one substance, as shown in Table 6.
Sample No. | Origin | Pesticide |
Amount (mg/kg)
|
> MRL*
|
---|---|---|---|---|
Sample 1 | Turkey |
Boscalid |
0.30 |
yes |
Cypermethrin |
0.28 |
yes |
||
Deltamethrin |
0.066 |
|
||
Kresoxim-methyl |
0.016 |
|
||
Metalaxyl (-M) |
0.071 |
yes |
||
Triadimefon, sum |
0.21 |
yes |
||
Sample 2 | Turkey |
Boscalid |
0.37 |
yes |
Cypermethrin |
0.37 |
yes |
||
Dithiocarbamate |
4.0 |
yes |
||
Kresoxim-methyl |
0.67 |
|
||
Metalaxyl (-M) |
0.21 |
yes |
||
Metrafenone |
0.96 |
yes |
||
Triadimefon, sum |
2.7 |
yes |
||
Trifloxystrobin |
2.8 |
yes |
||
Sample 3 | Bulgarien |
Flusilazole |
0.024 |
yes |
Iprodione |
0.018 |
yes |
||
Sample 4 | Turkey |
Chlorpyrifos |
0.066 |
yes |
Dithiocarbamate |
0.59 |
yes |
||
Endosulfan, sum |
0.12 |
yes |
||
Nicotine |
0.030 |
yes |
||
Triadimefon, sum |
0.47 |
yes |
||
Sample 5 | Bulgarien |
Azoxystrobin |
0.17 |
yes |
Boscalid |
0.14 |
yes |
||
Chloranthraniliprole |
0.029 |
|
||
Chlorpyrifos |
0.51 |
yes |
||
Cyflufenamid |
0.013 |
|
||
Dimethomorph |
0.025 |
yes |
||
Dithiocarbamate |
0.92 |
yes |
||
Famoxadone |
0.039 |
yes |
||
Fenbutatin-oxide |
0.34 |
yes |
||
Fosetyl, sum |
2.3 |
yes |
||
Iprodione |
1.3 |
yes |
||
Lambda-Cyhalothrin |
0.036 |
yes |
||
Methoxyfenozide |
1.4 |
yes |
||
Myclobutanil |
0.21 |
yes |
||
Penconazole |
0.084 |
yes |
||
Pyrimethanil |
0.24 |
yes |
||
Tebufenpyrad |
0.20 |
yes |
||
Tetraconazole |
0.013 |
|
||
Triadimefon, sum |
0.15 |
yes |
||
Sample 6 | Turkey |
Chlorpyrifos |
0.014 |
|
Fosetyl, sum |
2.4 |
yes |
||
Lambda-Cyhalothrin |
0.77 |
yes |
||
Nicotine |
0.025 |
yes |
||
Triadimefon, sum |
3.4 |
yes |
||
Sample 7
|
Turkey |
Dithiocarbamate |
1.3 |
yes |
Fluopyram |
10.5 |
yes |
||
Imazalil |
0.043 |
|
||
Lambda-Cyhalothrin |
0.090 |
yes |
||
Metalaxyl (-M) |
0.13 |
yes |
||
Nicotine |
0.015 |
yes |
||
Pyraclostrobin |
0.056 |
yes |
||
Tebuconazole |
1.2 |
yes |
||
Triadimefon, sum |
0.036 |
|
The analyses will continue in 2017.
„Super foods“
Moringa, along with other alleged “super foods” such as cereal grasses, spirulina, chlorella and maca, is currently very popular. The dried, pulverized leaves are supposed to be sprinkled over breakfast cereal or used in smoothies. The more convenient method is the consumption of a moringa powder capsule.
Moringa and other “super foods” are often offered as products of organic cultivation. Only four of the moringa samples analyzed in 2016 were conventionally produced.
Sample No. | Origin | Pesticide |
Quantity (mg/kg)
|
> MRL*
|
---|---|---|---|---|
Sample 1 | Not specified |
Acetamiprid |
0.12 |
yes |
BAC (n=8-18) |
0.15 |
yes |
||
Bromide |
17.1 |
|
||
Carbendazim, sum |
0.056 |
|
||
Chlorate |
0.012 |
yes |
||
Chlorpyrifos |
0.018 |
|
||
Cypermethrin |
4.1 |
yes |
||
Deltamethrin |
0.16 |
yes |
||
Emamectin B1a/B1b |
0.021 |
yes |
||
Fipronil, Sum |
0.089 |
yes |
||
Imidacloprid |
0.026 |
|
||
Lambda-Cyhalothrin |
0.84 |
|
||
Lufenuron |
0.15 |
yes |
||
Methomyl, sum |
1.1 |
yes |
||
Permethrin |
1.7 |
yes |
||
Profenofos |
0.15 |
yes |
||
Trimethylsulfonium cation |
0.034 |
|
||
Sample 2 | Not specified |
BAC (n=8-18) |
0.076 |
|
Bromide |
59.9 |
|
||
Chlorpyrifos |
0.011 |
|
||
Trimethylsulfonium cation |
0.019 |
|
||
Sample 3 | Philippines |
2,4-D |
0.023 |
|
Trimethylsulfoneium-Cation |
0.078 |
yes |
||
Sample 4 | Philippines |
Atrazin |
0.023 |
|
Bromide |
42.4 |
|
||
Emamectin B1a/B1b |
0.012 |
|
||
Lambda-Cyhalothrin |
0.17 |
|
||
Nicotine |
0.71 |
yes |
||
Trimethylsulfonium cation |
0.12 |
yes |
A detailed presentation on moringa, including data on the organic samples, can be found on our Homepage.
Other „super foods“ are from cereal or fruit products, such as chia seeds and goji berries. In 2016, five samples of conventionally produced chia seeds and goji berries were analyzed, all of which exceeded the maximum residue levels.
Type of Sample | Origin | Pesticide |
Quantity (mg/kg)
|
> MRL*
|
---|---|---|---|---|
Chia | Not specified |
Fosetyl, sum |
0.28 |
|
Haloxyfop, sum |
0.11 |
yes |
||
Chia | Not specified |
Glyphosate |
1.1 |
yes |
Goji | China |
2,4-D |
0.019 |
|
Acetamiprid |
0.28 |
|
||
Amitraz, sum |
0.081 |
|
||
Azoxystrobin |
0.014 |
|
||
Carbendazim, sum |
0.11 |
|
||
Carbofuran, sum |
0.050 |
yes |
||
Chlorpyrifos |
0.083 |
|
||
Cypermethrin |
0.12 |
|
||
Difenoconazole |
0.088 |
|
||
Fenpropathrin |
0.014 |
|
||
Imidacloprid |
0.076 |
|
||
Iprodione |
0.012 |
|
||
Kresoxim-methyl |
0.021 |
|
||
Lambda-Cyhalothrin |
0.044 |
|
||
Prochloraz, sum |
0.083 |
|
||
Propargit |
0.042 |
|
||
Pyridaben |
0.026 |
|
||
Tebuconazole |
0.094 |
|
||
Thiamethoxam |
0.040 |
|
||
Thiophanat-methyl |
0.098 |
|
||
Triadimefon, sum |
0.037 |
|
||
Goji | Not specified |
Acetamiprid |
0.22 |
|
Amitraz, sum |
0.062 |
|
||
Carbendazim, sum |
0.12 |
|
||
Carbofuran, sum |
0.019 |
yes |
||
Chlorpyrifos |
0.028 |
|
||
Cypermethrin |
0.067 |
|
||
Difenoconazole |
0.036 |
|
||
Imidacloprid |
0.068 |
|
||
Lambda-Cyhalothrin |
0.020 |
|
||
Prochloraz, sum |
0.085 |
|
||
Propargit |
0.044 |
|
||
Pyridaben |
0.024 |
|
||
Tebuconazole |
0.017 |
|
||
Thiophanate-methyl |
0.015 |
|
||
Triadimefon, sum |
0,021 |
|
||
Goji | Not specified |
Acetamiprid |
0.13 |
|
Acetamiprid Metabolit IM-2-1 |
0.019 |
|
||
Amitraz, sum |
0.024 |
|
||
Anthrachinon |
0.024 |
|
||
Carbofuran, sum |
0.013 |
yes |
||
Imidacloprid |
0.011 |
|
||
Nicotine |
0.12 |
yes |
||
Triadimefon, sum |
0.012 |
|
A presentation of our analytical results for organically produced “super foods” can be found in our organic monitoring report from 2016 (only German).
Further exceedances of the maximum residue level (excluding chlorate) are listed in Table 9. There are no particular groupings – most are single cases. Processed foods are not required to provide the country of origin, so the origin is mostly unknown.
Type of food | Substances w/ exceedances of the MRL |
---|---|
Red currants, frozen |
Ethephon (2x); Fenazaquin (2x) |
Buckwheat |
Glyphosate (3x) |
Millet |
Glyphosate |
Rye |
Dichlorvos |
Chickpeas |
Fosetyl, sum |
Lentils |
Piperonyl butoxide |
Potatoes |
Flonicamid, sum; Fluazifop; Fosetyl, sum; Haloxyfop, sum |
Potatoes, blanched |
BAC (n=8-18) |
Cultured mushrooms |
Mepiquat; Trimethylsulfoneium-Cation |
Oil seeds |
Glyphosate; Haloxyfop, sum |
Baby food |
Fosetyl, sum (4x) |
Manioc |
Nicotine |
Hedgehog mushrooms |
Chlorpropham |
Porcini mushroom, dried |
Nicotine |
Photo credits:
CVUA Stuttgart, pesticide laboratory.
References:
[2] Entscheidung der Kommission vom 10. November 2008 über die Nichtaufnahme von Chlorat in Anhang I der RL 91/414/EWG des Rates und die Aufhebung der Zulassungen für Pflanzenschutzmittel mit diesem Stoff (ABl. L307/7 vom 18.11.2008)
Translator:
Catherine Leiblein.
Annex
Parameter
|
In der Rückstandsdefinition enthalten und analytisch erfasst |
---|---|
Abamectin |
Avermectin B1a |
Aldicarb, sum |
Aldicarb |
Amitraz, total |
Amitraz |
Benzalkonium chloride, sum (BAC) |
Benzyl dimethyl octyl ammonium chloride (BAC-C8) |
Carbofuran, sum |
Carbofuran |
DDT, sum |
DDE, pp- |
Dialkyl dimethyl ammonium chloride, sum (DDAC) |
Dioctyl dimethyl ammonium chloride (DDAC-C8) |
Dieldrin, sum |
Dieldrin |
Dimethoate, sum |
Dimethoate |
Disulfoton, sum |
Disulfoton |
Endosulfan, sum |
Endosulfan, alpha- |
Fenamiphos, sum |
Fenamiphos |
Fenthion, sum |
Fenthion |
Fipronil, sum |
Fipronil |
Flonicamid, sum |
Flonicamid |
Fosetyl, sum |
Fosetyl |
Glufosinate, sum |
Glufosinate |
Heptachlor, sum |
Heptachlor |
Malathion, sum |
Malathion |
Methiocarb, sum |
Methiocarb |
Methomyl, sum |
Methomyl |
Milbemectin |
Milbemectin A3 |
Oxydemeton-S-methyl, sum |
Oxydemeton-methyl |
Parathion-methyl ,sum |
Parathion-methyl |
Phorate, sum |
Phorate |
Phosmet, sum |
Phosmet |
Pirimicarb, sum |
Pirimicarb |
Prochloraz, total |
Prochloraz |
Pyrethrum, Sum |
Pyrethrin I |
Pyridate, sum |
Pyridate |
Quintozen, sum |
Quintozen |
Sethoxydim, total |
Sethoxydim |
Spirotetramat, sum |
Spirotetramat, |
Terbufos, sum |
Terbufos |
Tolylfluanid, sum |
Tolylfluanid |
Triadimefon & Triadimenol |
Triadimefon |
Triflumizole |
Triflumizole |