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
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?
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.
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 approach，FOOD QUALITY & SAFETY
BY UDO LAMPE、JUAN HAMDI、ABRAHAM WELDAY、SEBASTIAN BIHL、J.-PETER KRAUSE，PHD
Feed:character Bin，BeijingZhongshiguojinInternational laboratory capability verification research Co., Ltd