Food safety in Thailand. 3: Pesticide residues detected in mangosteen (Garcinia mangostana L.), queen of fruits.

BACKGROUND: For developing countries like Thailand, regulation of pesticide usage exists, but it is not fully enforced. Therefore, pesticide residues in vegetables and fruits have not been well monitored. This study aimed to determine the pesticide residues in mangosteen fruits sold in Thailand. The mangosteen samples (n = 111) were purchased and the contents of 28 pesticides were analysed by GC-MS/MS method.

RESULTS: Of the pesticides tested, eight were found in 100% of the mangosteen samples. However, in 97% of these samples, either chlorothalonil, chlorpyrifos, diazinon, dimethoate, metalaxyl or profenofos was detected exceeding their maximum residue limits (MRLs), representing a 97% rate of pesticide detection above the MRL. This rate is much higher than those found in other fruits sold in developed countries. However, this conclusion excludes the fresh Thai mangosteens grown for export, as these are generally cultivated and harvested to GAP standards. Since the edible part of the mangosteen is the pulp, washing the fruits with running water can reduce the risk of pesticide residues contaminating the pulp which would be eaten by the consumer.

CONCLUSION: The findings strongly suggest that routine monitoring of pesticide residues in fruits and vegetables is required to reduce the health risks associated with consuming contaminated food. © 2016 Society of Chemical Industry.