Reduction of pesticide residues from teff (Eragrostis tef) flour spiked with selected pesticides using household food processing steps

Abstract

Teff ( Eragrostis tef ) is an ancient cereal that is indigenous from Ethiopia. Nowadays, teff grain is becoming popular to many parts of the world. Teff is gluten-free in nature, has high iron and fiber content, and many other health benefits make this crop interesting to many consumers. Since no insect pests are attacking the teff grains, farmers do not apply pesticides on it, unlike maize and other grains. Nevertheless, residues of organochlorine pesticides have been detected at an alarming level that could pose a consumer risk. Teff is often consumed as injera which is a fermented flat pancake. The main aim of the present study is, therefore, to investigate the effect of household food processing (doughing and baking) on the reduction of pesticide residues from teff. Pesticide residues previously detected in teff grain such as permethrin, cypermethrin, deltamethrin, chlorpyrifos ethyl, p,p’-DDE, p,p’-DDD, o,p’-DDT, and p,p’-DDT were spiked and extracted followed by the subsequent household processing which are generally doughing (dough making followed by fermentation) and baking. From the findings of this study, doughing decrease the pesticide residues in the range of 59.9–86.4% and baking in the range of 63.2–90.2%. Kruskal−Wallis analysis indicates that the reduction of pesticide residues by baking is significantly different from doughing (p-value < 0.0001). There is also a significant difference between non-fermented and fermented dough (p-value = 0.012). The processing factor for doughing and baking was less than one (PF < 1 = reduction factor) which indicates the reduction of pesticides due to teff processing. The cumulative effect of these processing methods is important to evaluate the risks associated with the ingestion of pesticides, particularly in teff grain.

Validation of a Rapid Multiresidue Method for the Determination of Pesticide Residues in Vine Leaves. Comparison of the Results According to the Different Conservation Methods

“…Washing with hot water was very effective in reducing residues of the polar pesticide, dimethoate, but did not have a significant effect on residues of the apolar compound, chlorpyrifos [ 48 ]. Morever, deltamethrin, permethrin, cypermethrin and chlorpyrifos were reduced to 59.9–86.4% and 63.2–90.2% during dough preparation and baking, respectively [ 49 ]. A total reduction of 87.98%, 73.69%, 85.93%, 71.31%, 78.18%, and 90.33% for deltamethrin, penconazole, kresoxim-methyl, cyproconazole, epoxiconazole and azoxystrobin were found respectively in a study on the effect of household rice cooking [ 46 ].…”

Estimativa de ingestão crônica de resíduos de agrotóxicos por meio da dieta

“…É importante destacar que existem poucos estudos sobre os efeitos ecotoxicológicos decorrentes da aplicação de agrotóxicos em regiões tropicais, sendo majoritariamente utilizados como referências estudos aplicados em regiões temperadas. É indicada a adaptação dos testes existentes para as regiões tropicais 47 .…”

Processing of Raw Agricultural Produce and its Effect on Pesticide Residues: A Review

“…The study also showed that the reduction of pesticide residues by baking is significantly different from doughing (p-value < 0.0001). There is also a significant difference between non-fermented and fermented dough (pvalue = 0.012) (Mekonen et al, 2019).…”