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Distribution analysis of pesticide residues in Strawberry

Author:UDO LAMPE、JUAN HAMDI、ABRAHAM WELDAY、

Sebastian bihl, Dr. j.-peter Krause

Strawberries are popular partly because they contain a lot of healthy substances, such as dietary fiber and polyphenols. However, strawberries are one of the most challenging horticultural crops. Growers must manage the diversity and complexity of pest problems. Chemical plant protectants, especially insect, mite and disease control agents, have always been a key component in maintaining crop yield and quality standards.

In order to protect consumers from the adverse effects of residues, the European Commission has developed a maximum residue level (MRL). Represents the expected maximum residual concentration if the pesticide is applied in accordance with good agricultural practice. Therefore, the authorities believe that MRL compliant products are safe and can be sold legally.

In addition to public regulations, major food retail groups have also developed private standards. In some cases, these specifications are much lower than official MRLs or other parameters (such as acute reference dose) (one/3 or lower in some cases).

Therefore, in the routine control analysis, the laboratory must analyze the fruit to evaluate the legal marketability of MRL. EU regulation No. 75two of two0one4 stipulates that for berries and small fruits, MRL applies to the whole product after removing crown leaves and stems (except raisins). In the case of strawberries, the canopy leaves must be removed. However, no data on the distribution of residues between fruits and leaves have been found in the literature, and therefore no effect of processed leaves on the concentration of residues in edible parts has been found. There is no indication of the extent to which the crown must be removed by substantial cutting or precision.

The aim of a recent study was to investigate the distribution of pesticide residues between leaves and fruits in order to assess the risk of incomplete removal of crown leaves.

Materials and methods

Strawberries (500g boxes) were purchased from local supermarkets and processed and analyzed according to the multi residue method for pesticide residue determination. Compared with the conventional method of separating the crown leaf from a small part of the fruit, in this study, only the crown leaf (green part) was completely removed, while no part of the fruit was removed, as shown in Figure one.

chartone The crown leaf (green part) is completely removed and the fruit has no other part

The edible parts of the fruit are homogenized in a blender(Mycook one.8,Taurus Professional)。将绿色部分填充到低温研磨机(Retsch CryoMill)的瓶子中。将瓶子冷却至约-30摄氏度(冷震霜SF 5one,Nordcap),然后在没有进一步冷却的情况下将冻结的绿色部分研磨3分钟,见charttwo。之后,按照QUEchERs的方法,通过溶剂萃取萃取农药。采用气相色谱法结合串联质谱法(德国安捷伦)对农药进行测定。用同样的方法处理果肉。农药残留浓度根据产品的千克鲜重(mg/kg)计算为毫克农药。

charttwo The edible parts of the fruit are homogenized in a blender

Results and discussion

共准备了30盒草莓用于调查。仅去除冠叶的方法导致叶和果实之间的平均重量比为0.0onetwo,见chart3。

叶面和果实间的农药残留浓度比在6到two77之间,变化很大。这种变化是由于样品的选择不具体,可能在处理、果实生长、贮藏等方面有所不同,并影响比例。此外,5two%的样品中,残留量仅在叶子中测量,而在水果中未测量。通常可以检测到草莓的典型残留物,并用于评估分布情况,见chart4。农药的发现越多,因子的变化越大。由于未满足统计要求,因此无法计算平均分布系数。

But the results clearly showed that the pesticide concentration in leaves was much higher than that in fruits.

IfWhat happens when a small part of the crown leaf is analyzed together with the fruit?

计算的最高因子为two77。If整个草莓均质化,残渣浓度将增加4.two倍。只有one0%的冠叶会将浓度增加one.3倍,这对于MRL较低的农药来说至关重要,并可能导致假阳性结果。

The crown leaf of strawberry should be cut clearly below the crown leaf to ensure complete removal. Consumers should also do so to avoid unnecessary ingestion of residues.

chart3 仅去除冠叶的方法导致叶与果实之间的平均重量比为0.0onetwo。

chart4 通常可以检测到草莓的典型残留物并加以利用

Used to evaluate distribution.

Cyprodinil  AzoxystrobinBacterial ringamine

Fludioxonil  FluorodioxygenAzoxystrobin啶

Fluopyram   fluorinePiRen

Pyrimethanil   乙amineAzoxystrobin啶

Trifloxystrobin  TrioxysspecialRobin

Original:Pesticide Residue Distribution in Strawberries——A methodological approachFOOD QUALITY & SAFETY

BY  UDO LAMPE、JUAN HAMDI、ABRAHAM WELDAY、SEBASTIAN BIHL、J.-PETER KRAUSE,PHD

Feed:character BinBeijingZhongshiguojinInternational laboratory capability verification research Co., Ltd