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Effect of Household Coffee Processing on Pesticide Residues as a Means of Ensuring Consumers’ Safety

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HCoffee is the highly consumed and popular beverage all over the world. However, coffee beans used for the daily consumption may contain pesticide residues which may cause adverse health effects to consumers. In this monitoring study, the effect of household coffee processing on pesticide residues in coffee beans was investigated. Twelve pesticides including metabolites and isomers (endosulfan α, endosulfan β, cypermethrin, permethrin, deltamethrin, chlorpyrifos ethyl, heptachlor epoxide, hexachlorobenzene, p'p-DDE, p'p-DDD, o'p-DDT and p'p-DDT) were spiked in coffee beans collected from local market in southwestern Ethiopia. The subsequent household coffee processing (washing, roasting and brewing) conditions were established as close as possible with the traditional household coffee processing in Ethiopia. The percent reduction in washing process is in the range of 14.63- 57.69, while the roasting reached up to 99.8 percent. Chlorpyrifos ethyl, permethrin, cypermethrin, endosulfan α and β in roasting and all of the 12 pesticides in the coffee brewing processes were not detected. Kruskal-Wallis analysis indicated that, the reduction of pesticide residues by washing is significantly different from roasting and brewing (P<0.0001). However, there was no significant difference between coffee roasting and brewing (P>0.05). The processing factor (PF) was less than one (PF<1), which indicates reduction of pesticides under study during processing of the coffee beans. The cumulative effect of the three processing methods has a paramount importance in evaluating the risks associated with ingestion of pesticide residues, particularly in coffee beans.
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Eect of Household Coee Processing on Pesticide Residues as a
Means of Ensuring ConsumersSafety
Seblework Mekonen,*
,,
Argaw Ambelu,
and Pieter Spanoghe
Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
Department of Environmental Health Sciences and Technology, College of Health Sciences, Jimma University, Jimma, Ethiopia
ABSTRACT: Coee is a highly consumed and popular beverage all over the world; however, coee beans used for daily
consumption may contain pesticide residues that may cause adverse health eects to consumers. In this monitoring study, the
eect of household coee processing on pesticide residues in coee beans was investigated. Twelve pesticides, including
metabolites and isomers (endosulfan α, endosulfan β, cypermethrin, permethrin, deltamethrin, chlorpyrifos ethyl, heptachlor
epoxide, hexachlorobenzene, pp-DDE, pp-DDD, op-DDT, and pp-DDT) were spiked in coee beans collected from a local
market in southwestern Ethiopia. The subsequent household coee processing conditions (washing, roasting, and brewing) were
established as closely as possible to the traditional household coee processing in Ethiopia. Washing of coee beans showed
14.6357.69 percent reduction, while the roasting process reduced up to 99.8 percent. Chlorpyrifos ethyl, permethrin,
cypermethrin, endosulfan αand βin roasting and all of the 12 pesticides in the coee brewing processes were not detected.
KruskalWallis analysis indicated that the reduction of pesticide residues by washing is signicantly dierent from roasting and
brewing (P< 0.0001). However, there was no signicant dierence between coee roasting and brewing (P> 0.05). The
processing factor (PF) was less than one (PF < 1), which indicates reduction of pesticides under study during processing of the
coee beans. The cumulative eect of the three processing methods has a paramount importance in evaluating the risks
associated with ingestion of pesticide residues, particularly in coee beans.
KEYWORDS: coee ceremony, processing factor, roasting, washing, coee brewing
1. INTRODUCTION
In recent years, public health issues aecting the food chain
have triggered health authorities to increase their concern on
the presence of pesticide residues in staple food items.
Pesticides are widely used for the control of pests, disease of
crops, and vectors of human and animal diseases. Despite their
wide range of application, pesticides may have adverse health
eects for consumers because their residues remain on food
items. As a result, food safety is a growing concern worldwide
because of its direct relation to human health. It is important
for consumers to know the possibilitiy of intake of pesticides
along with their food. As reported in the literature, food
processing may reduce pesticide residues in food and the
concurrent scenario of unsafe food for consumers.
1
Pesticide residue can be detected in any food items, such as
vegetables and fruits, cereals, animal products, or tea and coee
as a result of the application of the pesticides in the eld and
during storage of crops for the control of pests. Usually,
pesticide residue analysis is undertaken for raw agricultural
commodities to meet the purpose of marketing to consumers,
import/export certication, regulatory monitoring, and others.
However, to estimate the level of exposure to pesticide residues
in food, it is desirable to investigate the level of exposure at the
point of consumption, mainly after food processing, which may
lead to a large reduction of pesticide residues.
2
Food processing
is the action of transforming the food to more edible form
before the food is consumed and the processing can inuence
the pesticide residue present after the raw agricultural
commodity is harvested.
3
Dierent household and industrial
food processing, such as washing with water or with various
chemicals, peeling for fruits and vegetables, frying, boiling,
cooking, and baking, have been able to reduce the pesticide
residue in food to below the risk level.
4
Coee is a highly consumed and popular beverage all over
the world. Coee is the second most important commodity
next to oil as a source of foreign exchange for most producing
countries. In addition, it is considered a primary food due to its
contents of compounds with an antioxidant eect and other
benecial biological properties. Its characteristic avor and
aroma make it a unique beverage, and thousands of volatile
compounds are found in roasted coee.
5
Currently, Ethiopia is
the fth largest world coee producer and the top producer and
exporter in Africa. The country is believed to be the origin of
Coee arabica. On the other hand, half of the coee produced in
Ethiopia is used for domestic consumption. This makes the
nation to be the leading African country in coee consumption
with a yearly per capita consumption of 2.4 kg. Additionally,
coee is the most signicant agricultural product to the
countrys economy.
6
Specically, the beautiful traditional coee ceremony makes
the country very unique in consumption of coee. The coee
ceremony and drinking coee is an important part of Ethiopian
cultures. Coee is oered during holidays, visiting friends, and
on a daily basis as a staple food item. The Ethiopian coee
ceremony starts with washing the coee beans with water and
Received: July 10, 2015
Revised: September 1, 2015
Accepted: September 7, 2015
Published: September 7, 2015
Article
pubs.acs.org/JAFC
© 2015 American Chemical Society 8568 DOI: 10.1021/acs.jafc.5b03327
J. Agric. Food Chem. 2015, 63, 85688573
roasting until it turns to dark brown. After roasting, sometimes
the roasted coee beans are brought to the family members or
visitors to allow them to experience the aroma. Afterwards, it
will be ground to a ne powder using a traditional wooden
mortar and pestle. The powder is poured into boiled water in a
special local coee clay pot called a jebena.Coee will be
ready to serve when the steam with an attractive avor starts to
come out from the nozzle. After that, the jebena is placed on
ground for about 3 min to let the coee sludge settle to the
bottom. The brewed coee is then poured into small cups and
served (personal observation). In general, coee is an
important crop for domestic consumption as well as a source
of hard currency for the nation.
However, studies have indicated that coee beans have
dierent pesticide residues. Even though coee is the most
important agricultural product for human consumption as well
as for the economic growth of the producing countries, the
beans might have dierent pesticide residues that can expose
consumers to hazardous agrochemicals.
7
Because of the high
consumption of coee and its economic importance, people
from the producer, exporter, and consumer countries give more
attention to its safety.
8
Even though pesticide contamination in
green coee beans is limited during agricultural treatments,
there may be contamination during transportation and storage.
9
Dierent studies have stated that coee is contaminated by
dierent classes of pesticides applied in the eld. According to
the U.S. Food and Drug Administration, from a survey of 60
imported green coee bean samples, some of them contained
dierent pesticide residues, such as chlorpyrifos at a
concentration ranging from 0.01 to 0.04 mg/kg and pirimiphos
methyl at 0.01 mg/kg.
10
From a study done in Brazil, the
residues of dierent pesticides, such as endosulfan, chlorpyrifos,
cypermethrin, and captafol, have been detected in coee beans
from either registered or illegal use.
11
Additionally, from the
previous study done in Ethiopia, DDT, cypermethrin,
permethrin, deltamethrin, chlorpyrifos ethyl, and endosulfan
(αand β) were detected in coee beans at concentrations
ranging from 0.011 to 1.115 mg/kg7.
The pesticide residues, to a variable extent, left in the food
materials after harvesting, are beyond the control of consumers
and may have deleterious eects on human health. Because
Ethiopia is the largest producer, exporter, and consumer of
coee in Africa, a pragmatic solution should be developed to
tackle the problem of coee safety. Dierent studies have
revealed that food processing can be one important solution
that has a signicant role for the reduction of pesticide residues
in dierent food items.
24,12
Nowadays, there is an increasing
need for information on the eect of various food processes on
pesticide residues. Few studies have indicated the eect of
coee roasting on the reduction of pesticide residues.
13,14
However, no studies are available on the eect of household
coee processing (washing, roasting, and brewing) methods on
pesticide residues. Therefore, the main aim of the present study
is to evaluate the eect of household processing on pesticide
residues in coee and to determine the processing factor (PF)
for each of the processing steps.
2. MATERIALS AND METHODS
2.1. Chemicals and Reagents. Analytical grade acetoni-
trile (99.9% purity) was supplied by VWZ-prolabo. High
performance liquid chromatography grade n-hexane (98%
purity) and acetone (98.9% purity) that were obtained from
ALLthec were used to extract the pesticide residues from the
raw coee beans and after dierent processing steps. Thermo
Fisher Scientic supplied MgSO4(98% purity), NaAc (99%
purity), the 50 mL centrifuge tube, the 15 mL dispersive solid
phase extraction cleanup tube packed with primary secondary
amine (PSA: 99% purity), magnesium sulfate (MgSO4, 98%
purity), and octadecyl (C18, 99% purity). The pesticides under
study (pp-DDE (99.9%), pp-DDD (99.3%), op-DDT
(100%), pp-DDT (99%), endosulfan α(98.5%), endosulfan
β(98%), Permethrin (98%), cypermethrin (98%), deltamethrin
(99%), Chlorpyrifos ethyl (99.5%), Heptachlor epoxide
(99.5%) and hexachlorobenzene (98%)) with their highest
analytical purity, were obtained from Supelco and delivered by
Sigma-Aldrich Logistic Analytical. The physicochemical proper-
ties of the pesticides studied in the present study are presented
in Table 1.
2.2. Sampling. A 3 kg portion of green coee beans was
bought from a local market in Jimma zone, southwestern
Ethiopia in August, 2014 and served as a blank and spiked
sample. Samples were packed in polyethylene plastic bags, after
which they were sealed and labeled properly. The samples were
transported to the laboratory and stored at 20 °C until
extraction was done.
2.3. Quality Control. 2.3.1. Linearity. The quantitative
determination of the pesticide residues in processed and
unprocessed coee beans was done on the basis of an external
standard method. The calibration curves were obtained by
injecting ve dierent concentrations of the pesticide standards
in the range of 0.0051 mg/L. The regression coecient (r2)
was >0.995 for all the pesticides under study. Identication and
quantication of the pesticides were done on the basis of the
retention time and peak area, respectively.
2.3.2. Recovery Study. To evaluate the performance of the
analytical procedures recovery (% recovery), studies were
undertaken for each pesticide. A 10 g sample of pesticide-free
coee beans was weighed on the analytical balance and spiked
with 40 μL of 100 mg/L of each pesticide in three replicates.
The extraction was performed in a similar way with the
samples. The percent recovery was derived from the equation:
(amount of pesticide observed)/(amount of pesticides spiked)
×100. The percent relative standard deviation (% RSD) was
obtained by dividing the standard deviations by the average
concentration and multiplying the result by 100.
Table 1. Physicochemical Properties of the Pesticides under
Study
a
pesticides
water
solubility
(mg/L) log
kow
vapor pressure
(mmHg) mode of
action
pp-DDE 0.025 6.91 1.6 ×107contact
pp-DDD 0.120 6.51 1.4 ×106contact
op-DDT 0.090 6.02 6.0 ×106contact
pp-DDT 0.085 6.79 1.1 ×107contact
endosulfan α0.530 3.83 1 ×105contact
endosulfan β0.280 3.62 1 ×105contact
permethrin 0.006 6.10 2.15 ×108contact
cypermethrin 0.009 5.40 2.3 ×107contact
deltamethrin 0.002 6.10 1.5 ×108contact
heptachlor epoxide 0.350 5.40 3.0 ×104contact
hexachlorobenzene 0.006 5.73 1.09 ×105systemic
chlorpyrifos ethyl 1.400 4.70 1.9 ×105contact
a
log kow = logarithm of octanol-water partion coecient.
Journal of Agricultural and Food Chemistry Article
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2.4. Treatment of Raw Coee Bean. A 10 g portion of
raw coee beans was weighed on an analytical balance and
spiked with 40 μL of a 100 mg/L solution of each pesticides
under study (DDT metabolites, cypermethrin, deltamethrin,
permethrin, endosulfan [α,β] and chlorpyrifos ethyl,
heptachlor epoxide, and hexachlorobenzene) in three replicates
to increase the reliability of the results. Spiking was done for
each household coee processing method (washing, roasting,
and brewing). The pesticides selected for this study were
detected in the previous study done on Ethiopian coee beans,
7
except for heptachlorepoxide and hexachlorobenzene, in which
the investigators expected them from previous application in
the environment. The spraying of the coee beans was done in
a Petri dish to get equal distribution of the pesticides for each
bean. After spraying, the Petri dishes were covered with
aluminum foil and placed in refrigerator at 4 °C for 24 h to
increase the contact time between the pesticides and the matrix.
After 1 day, the processing methods (washing, roasting,
brewing) and the extraction, clean up, and analysis were
followed as stated below.
2.5. Extraction and Cleanup of the Samples. To assess
the eect of washing, roasting, and brewing of coee on
pesticide residues, the extraction and cleanup of the raw and
processed coee beans were done using the modied Quick,
Easy, Cheap, Eective, Rugged and Safe (QuEChERS) method
combined with a dispersive solid phase extraction cleanup (d-
SPE) method. The analytical procedure was based on the
method AOAC 2007.01.
15
The subsequent processing steps of
the coee beans were done to correspond, as closely as
possible, to the actual traditional household coee processing in
Ethiopia. Blank coee bean (nonspiked) was also analyzed
together with the raw and processed coee beans. The
extraction and cleanup procedures for raw coee beans and
processed coee beans were as follows:
2.5.1. Raw coee beans. After holding the spiked samples
for 1 day, the treated raw coee bean was ground and
homogenized using a coee grinder with a knife in it. A 15 mL
portion of acetonitrile was added, and the sample was shaken
by hand for 30 s. Then 6 g of MgSO4/1.5 g of NaCl/1.5 g of
Na3citrate·2H2O/0.750 g of Na2Hcitrate was added, and the
mixture was again shaken for 5 min to prevent formation of
agglomerates between the water and MgSO4. Then the samples
were centrifuged at 5000 rpm for 5 min. The upper organic
layer was taken for cleanup using a 15 mL dispersive solid phase
extraction tube (d-SPE) containing 300 mg of PSA, 900 mg of
MgSO4, and 150 mg of C18 and then shaken for 30 s. The
cleaned extracts were centrifuged to get a clear solution. After
centrifugation, 5 mL of the upper layer was taken into a 100 mL
at bottom ask and evaporated to dryness using a rotary
evaporator (N18673 Rotavapor; Buchi) at a temperature of 40
°C. A 2 mL portion of n-hexane/acetone (9:1 V/V) was added
for solvent exchange to make the sample amenable for GC/
ECD analysis. The blank coee bean was also extracted in a
similar way, as were with the spiked samples. Then the extract
was placed into a vial for GC/ECD analysis.
2.5.2. Washed Coee Beans. The spiked coee beans were
washed thoroughly for 5 min under normal tap water (2530
°C), which resembles coee bean washing at the household
level. Then all other procedures for the unprocessed coee
beans were applied for the extraction, cleanup, and analysis for
the presence of pesticides.
2.5.3. Roasted Coee Beans. The spiked coee beans were
roasted on a stove at a temperature range of 230240 °C (light
to medium) roasting and an average time of 1214 min until
the characteristics aroma or avor of coee appears. The
roasting temperature and duration of roasting was based on a
study done by Moon and Shibamoto.
16
The roasting processes
were done in a way similar to the traditional Ethiopian
household coee roasting procedures. Then the other
procedures for extraction and cleanup used for raw coee
beans were applied.
2.5.4. Brewed Coee Beans. Some heat-resistant pesticides
may be detected in a cup of coee after the coee beans were
roasted. To determine the eect of brewing on the pesticides
under study, the brewing process was also undertaken. The
roasted coee beans were ground to a ne powder using a
coee grinder (type 4041, 220-230 V/150w). The ne coee
powder was added to a coee pot traditionally called a Jebena
containing 100 mL boiled water and brewed for 1012 min in
a way similar to that of the tradition Ethiopian coee brewing
processes (personal observation). After brewing, the coee pot
was picked up from the stove and put on the ground until the
infusion of the coee was cooled and the coee powder or
sludge had settled to the bottom of the coee pot. Then the
upper liquid layer was removed carefully to the cups, and then
extraction, cleanup and analysis of the brewed coee solution
was done in a way similar to that of the raw coee beans.
2.6. Determination of Processing Factor (PF). The
eect of household processing on the level of pesticides often
correlates with the physicochemical properties of the pesticides
under study, so it is important to adequately monitor the
processing factor. The processing factor (PF) for all trans-
formation steps was calculated as the ratio between the
pesticide concentrations in the processed commodity (mg/kg)
to the pesticide concentration in unprocessed (raw) commod-
ity (mg/kg). According to Bonnechere and his colleagues,
17
a
PF of <1 indicated that there is reduction of pesticides by the
processing method (PF < 1 = reduction factor), whereas >1
indicated no reduction in weight or volume, (PF > 1 = a
concentration factor). The processing factor is the proportional
amount by which residues change when food is processed. For
this study, it is calculated by the formula below:
=
processing factor (PF)
concentration of pesticides in processed coffee beans (mg/kg)
concentration of pesticides in raw coffee beans (mg/kg)
After obtaining the processing factor, the percent reduction (%
reduction) for each processing method was calculated as
follows: % reduction = (1 PF) ×100.
2.7. Wash Water and Coee Sludge Remaining at the
Bottom of Pot after Coee Brewing. Before the coee was
roasted, it was washed with water (which may remove some
residues on the surface of the coee beans). Additionally, after
the coee was brewed, there is sludge (powder or coee
residue) remaining in the bottom of the coee pot, which may
contain some pesticide residue that can evade the roasting
process. Traditionally, this wash water and coee sludge is often
disposed of in the environment, which may contaminate food
grown there. To check whether the wash water from the
samples and the sludge of the coee contain pesticide residues,
these two samples were analyzed. The procedure was as
follows: A 10 mL portion of the wash water (assuming 10 g of
water) and 68 g of coee sludge were weighed on an
analytical balance and placed into a 50 mL centrifuge tube.
Journal of Agricultural and Food Chemistry Article
DOI: 10.1021/acs.jafc.5b03327
J. Agric. Food Chem. 2015, 63, 85688573
8570
Then the extraction, cleanup, and analysis were done in a way
similar to that of the raw coee bean.
2.8. Analytical equipment. Quantitative estimations and
chromatographic separation of each pesticide were done by gas
chromatography with an electron capture detector (GCECD,
Agilent Technologies 6890N) with an auto sampler. The coee
bean processing was undertaken to see their eect on the
pesticides previously detected in Ethiopian green coee beans,
7
so the chromatographic conditions for this study were the same
as the previous paper, as explained below. A HP-5 capillary
column of 30 m ×0.25 mm i.d. ×0.25 μmlm thickness
coated with 5% phenyl methyl siloxane (model no. Agilent
19091J-433) was used in combination with the following oven
temperature program: initial temperature, 80 °C; ramp at 30 °C
min1to 180 °C; ramp at 3 °C min1to 205 °C; held for 4
min; ramp at 20 °C min1to 290 °C; held for 8 min; ramp at
50 °Cmin
1to 325 °C. For deltamethrin, the oven
temperature was maintained initially at 130 °C, held for 1
min, ramped at 30 °C min1to 280 °C, held for 16 min,
ramped at 50 °C min1to 325 °C, and held for 3 min. The total
GC run time was 27.92 min. Helium (99.9999% purity) was
used as a carrier gas at a ow rate of 20 mL min1, and nitrogen
was the makeup gas at a ow rate of 60 mL min1. An aliquot of
1μL was injected in split mode at a split ratio of 50:1 and
injection temperature of 280 °C. The pesticide residues were
detected with an electron capture detector (μ-ECD) operated
at a temperature of 300 °C. For the reliability of the results,
each sample was analyzed in triplicate, and the mean
concentration was computed accordingly.
2.9. Statistical Analysis. All the treatments for the three
processing methods were done in three replicates, and values
are shown as mean ±SD. Statistical signicance was checked
using the KruskalWallis test to see if the processing methods
(washing, roasting, and brewing) are dierent in the percent
reduction of the pesticides under study. Dierences at P< 0.05
were considered as signicant.
3. RESULTS AND DISCUSSION
3.1. Quality Control Studies. The mean percent recovery
for most of the pesticides was 80120% and the percent
relative standard deviation (% RSD) was below 10% for all the
pesticides under study, except for cypermethrin and deltameth-
rin. All pesticides were in the acceptable analytical range (70
120% recovery and RSD < 20%). The regression coecients
(r2) were >0.995 for all the pesticides. This method is accurate
and precise for the analysis of the pesticides under study and
fullled the requirement of European Document no. SANCO/
12495/2011.
18
The results are indicated in Table 2.
3.2. Eect of Household Processing of Coee Beans
on Pesticide Residues. This study investigated the eect of
household processing of coee (washing, roasting, and
brewing) on the stability of 12 pesticides, including metabolites
and isomers. The concentration of the pesticides under study in
raw and processed coee beans are presented in Figure 1.
Among the household processes, washing decreased the
pesticide residues by 14.6357.69%. This eect may be due
to the fact that most of the pesticides have contact action and
are found on the surface of the coee beans. This washing
process may help for the removal of the pesticides with the
silverskin of the coee (very thin layer of a coee bean located
just above the main part of the coee beans), dust, or soil.
Reports indicated that surface residues are easily amenable to
removal by simple washing processes with water.
4
The majority
of the pesticides applied to agricultural crops are conned to
the surface and a much smaller amount undergoes penetration
to the plant system.
19
As a result, they can easily be acquiescent
to being washed, trimmed, or peeled from the surface of the
crop. The maximum reduction was observed for endosulfan α
and β, for which the residue decreased by 53.1357.69%,
respectively. A similar result was observed from a study done in
India: washing of the vegetable brinjal with tap water decreased
endosulfan residue up to 55%; however, a lesser removal of
heptachlor epoxide in cucumber was observed.
20
The rinsability of some pesticides by washing with water may
not always correlate with its water solubility.
21
As indicated in
Table 1, most of the pesticides under study have low water
solubility and high octanol-water partition coecient (log kow >
3). Washing was found comparatively less eective in reducing
the residues of pp-DDD (14.63%), hexachlorobenzene
(20.83%), heptachlor epoxide (23.40%), chlorpyrifos ethyl
(26.53%), op-DDT ((28%), and pp-DDT (28%).
In this study, roasting was found to be eective in aecting
the stability of pesticide residues in coee beans. By this
process, reductions of the residues of the pesticides were in the
range of 72.599.8%. The maximum reductions were observed
in hexachlorobenzene (99.8%), heptachlor epoxide (97.9%),
pp-DDE, pp-DDD (97.6%), and op-DDT (96%). Five of the
Table 2. Results of Regression Coecient, Percent Recovery
and Percent RSD
a
pesticides r2% recovery % RSD
endosulfan α0.998 80 6.3
endosulfan β0.997 130 3.8
chlorpyrfos ethyl 0.995 122.5 2.0
permethrin 0.998 112.5 8.9
cypermethrin 0.999 127.5 19.6
deltamethrin 0.999 100 15.0
pp-DDE 0.999 102.5 2.4
pp-DDD 0.999 102.5 4.9
op-DDT 0.998 125 4.0
pp-DDT 0.988 125 2.0
heptachlorepoxide 0.999 117.5 10.6
hexachlorobenzene 0.999 120 0.20
a
RSD = relative standard deviation.
Figure 1. Mean pesticide residues (mg/kg) at dierent coee
processing steps. The error bars indicate standard deviation. Pesticides
from brewed coee were not detected and are not shown in this graph.
Journal of Agricultural and Food Chemistry Article
DOI: 10.1021/acs.jafc.5b03327
J. Agric. Food Chem. 2015, 63, 85688573
8571
spiked pesticides (chlorpyrifos ethyl, permethrin, cypermethrin,
and endosulfan αand β) were not detected after the roasting
process. This may be due to the instability of these pesticides to
the heat applied during the roasting process. Thermal
processing treatments such as cooking, backing, blanching,
steaming, and boiling have been found eective for the
breakdown of various pesticides, depending on the type of
pesticide.
22
Additionally, there may be a loss of the pesticides
during the application of heat depending on their phys-
icochemical properties, such as evaporation or thermal
degradations.
23
From a study done in Japan on the behavior
of pesticides in coee beans, the pesticide residues decreased a
signicant amount after the coee beans were roasted.
14
After the coee brewing process, none of the pesticides
under study were detected. This process is found to be the
most eective for the breakdown of the pesticides under study.
As it has been explained by Abou-Arab and Abou Donia,
24
the
elimination of the pesticide residue from the boiled extract
(brewed coee) may be due to the decomposition of the
pesticide residue by the application of heat during brewing. The
pesticide residues were signicantly inuenced by the roasting
and brewing processes. In general, the three household coee
bean processing methods have a cumulative eect in the
reduction of pesticides and help in solving health problems that
can occur from exposure to pesticides in coee.
3.3. Determination of the Processing Factor. The
processing factor for each pesticide from each processing step
was determined. The PFs for coee samples after each
processing step was <1, which indicated that the processing
methods have an eect on pesticide residues. A study done by
Bonnechere et al
17
has also indicated that a PF of less than a
unit is an indication of pesticide residue reduction due to a
specic food processing step. The PFs for the detected
pesticides in the roasting process were the lowest, particularly
for hexachlorobenzene. Heptachlorepoxide, pp-DDE, pp-
DDD, and op-DDT ranged from 0.001 to 0.04. This indicated
that the roasting process played the most important role in
removing the pesticides from coee beans compared with the
washing process. The processing factor was not calculated for
the pesticides not detected after the processing (Table 3).
The KruskalWallis test showed that there is a strong
variation in the stability of pesticide residues in coee beans
among the processing methods (P= 0.00001). The reduction
of pesticide residues due to washing is signicantly lower than
roasting (p= 0.0001) and brewing processes (P= 0.00001);
however, there is no signicant dierence between coee
roasting and coee brewing (P> 0.05). According to Hasmukh
et al.,
25
the washing process may depend on dierent factors,
such as location, age of residue, water solubility, and
temperature; this may be the reason for the variation. From
the household processing methods, roasting and brewing are
the most eective in decreasing the pesticides in coee beans.
3.4. Pesticide Residue in Wash Water and Coee
Sludge. To determine the level of pesticide liquid waste (wash
water) and the coee sludge that settled to the bottom of the
coee pot after the coee was brewed, these two samples were
analyzed. The result of the analyses revealed that all DDT
metabolites (pp-DDE, pp-DDD, op-DDT, and pp-DDT) and
deltamethrin were detected in the wash water (Figure 2). This
may be due to the fact that these pesticides have contact action
(acting on surface) and may be removed with the coee
silverskin and found in the wash water. Most of the pesticides
disappeared from the coee beans during the roasting process.
In the meantime, pesticides were not detected in the coee
sludge after brewing, except for deltamethrin and pp-DDT.
This may be because the percent reductions of deltamethrin
(72.5%) and pp-DDT (88%) after roasting of the coee beans
were low compared with other pesticides under study (Figure
2). The results indicated that the coee sludge should not be
scored when pouring the brewed coee into a cup before
human consumption. After brewing, it is necessary to wait some
time until the sludge of the coee completely settles to the
bottom of the coee pot.
In Ethiopia, the wash water from coee beans and the residue
from the brewed coee are discarded to the open environment,
which may pose contamination, so care should be taken during
the disposal of both the liquid (wash water) and semi-solid
coee sludge) waste. In addition, during pouring of the coee
solution to drink or serve coee, only the upper layer (not
mixed with the sludge at the bottom of the pot) should be used
for the safety of the consumers.
AUTHOR INFORMATION
Corresponding Author
*Phone: +32 (0)9264 60 12 Fax: +32 (0)9 264 62 49. E-mails:
sebleworkmekonen.shegen@ugent.be;seblework2001@yahoo.
com.
Notes
The authors declare no competing nancial interest.
Table 3. Processing Factor for the Eect of Washing,
Roasting and Brewing Processes
a
Pesticide PF Washing PF Roasting PF Brewing
endosulfan α0.47 aa
endosulfan β0.42 aa
chlorpyrefos ethyl 0.73 aa
permethrin 0.53 aa
cypermethrin 0.53 aa
deltamethrin 0.55 0.28 a
pp-DDE 0.73 0.02 a
pp-DDD 0.85 0.02 a
op-DDT 0.72 0.04 a
pp-DDT 0.72 0.12 a
heptachlor epoxide 0.77 0.02 a
hexachlorobenzene 0.79 0.001 a
a
Not detected and the processing factor is not calculated.
Figure 2. Average concentrations of pesticides detected in wash water
and coee sludge (mg/kg).
Journal of Agricultural and Food Chemistry Article
DOI: 10.1021/acs.jafc.5b03327
J. Agric. Food Chem. 2015, 63, 85688573
8572
ACKNOWLEDGMENTS
The authors are very grateful for a special research fund (BOF)
of Ghent University for sponsoring this study and Jimma
University for supporting the study. The authors also would
like to acknowledge Lillian Goeteyn and Claudine Schollaert
for their assistant in the laboratory work.
REFERENCES
(1) Kaushik, G.; Satya, S.; Naik, S. N. Food processing a tool to
pesticide residue dissipation A review. Food Res. Int. 2009,42 (1),
2640.
(2) Satpathy, G.; Tyagi, Y. K.; Gupta, R. K. Removal of
Organophosphorus (OP) Pesticide Residues from Vegetables Using
Washing Solutions and Boiling. J. Agric. Sci. 2012,4(2). DOI:
10.5539/jas.v4n2p69
(3) Pal, P.; Sahah, P. G. Effect of storage and processing on
dissipation of five insecticides on wheat. Pestic. Res. J. 2008,20 (2),
253258.
(4) Ahmed, A.; Randhawa, M. A.; Yusuf, M. V.; Khalid, N. Eect of
processing on pesticide residues in food crops-Ariview. J. Agric. Res.
2011,49 (3).379390
(5) Yeretzian, C.; Jordan, A.; Lindinger, W. Analysing the headspace
of coffee by proton-transfer-reaction mass-spectrometry. Int. J. Mass
Spectrom. 2003,223224, 115139.
(6) ICO. Ethiopian coee challenges and opportunities. ICO Annual
Review 2012.
(7) Mekonen, S.; Ambelu, A.; Spanoghe, P. Pesticide residue
evaluation in major staple food items of Ethiopia using the
QuEChERS method: A case study from the Jimma Zone: Pesticide
residues in food items. Environ. Toxicol. Chem. 2014,33 (6), 1294
1302.
(8) Yang, X.; Wang, J.; Xu, D. C.; Qiu, J. W.; Ma, Y.; Cui, J.
Simultaneous Determination of 69 Pesticide Residues in Coffee by
Gas ChromatographyMass Spectrometry. Food. Anal. Methods 2011,
4, 186195.
(9) Durand, N.; Gueule, D.; Fourny, G. Contaminants in coee. Cah.
Agric. 2006,23, 192196.
(10) Jacobs, R. M.; Yess, N. J. Survey of imported green coffee beans
for pesticide residues. Food Addit. Contam. 1993,10 (5), 575577.
(11) Pizzutti, I. R.; de Kok, A.; Dickow Cardoso, C.; Reichert, B.; de
Kroon, M.; Wind, W.; Weber Righi, L.; Caiel da Silva, R. A multi-
residue method for pesticides analysis in green coffee beans using gas
chromatographynegative chemical ionization mass spectrometry in
selective ion monitoring mode. J. Chromatogr. A 2012,1251,1626.
(12) Keikotlhaile, B. M.; Spanoghe, P.; Steurbaut, W. Effects of food
processing on pesticide residues in fruits and vegetables: A meta-
analysis approach. Food Chem. Toxicol. 2010,48 (1), 16.
(13) Cetinkaya, M.; von Düszeln, J.; Thiemann, W.; Silwar, R.
[Organochlorine pesticide residues in raw and roasted coffee and their
degradation during the roasting process]. Z. Lebensm.-Unters. Forsch.
1984,179 (1), 58.
(14) Sakamoto, K.; Nishizawa, H.; Manabe, N. Behavior of pesticides
in coffee beans during the roasting process. Shokuhin Eiseigaku Zasshi
2012,53 (5), 233236.
(15) Lehotay, S. J. Determination of Pesticide Residues in Foods by
Acetonitrile Extraction and Partitioning with Magnesium Sulfate:
Collaborative Study. J. AOAC Int. 2007,90 (2), 485520.
(16) Moon, J.-K.; Shibamoto, T. Role of Roasting Conditions in the
Profile of Volatile Flavor Chemicals Formed from Coffee Beans. J.
Agric. Food Chem. 2009,57 (13), 58235831.
(17) Bonnechere, A.; Hanot, V.; Jolie, R.; Hendrickx, M.; Bragard, C.;
Bedoret, T.; Van Loco, J. Processing Factors of Several Pesticides and
Degradation Products in Carrots by Household and Industrial
Processing. J. Food Res. 2012,1(3), DOI: 10.5539/jfr.v1n3p68
(18) Method validation and quality control procedures for pesticide
residues analysis in food and feed. Document No. SANCO/12495/
2011; National Food Administration: Uppsala, Sweden, 2011.
(19) Toker, İ.; Bayιndιrlι, A. Enzymatic peeling of apricots,
nectarines and peaches. LWT - Food Sci. Technol. 2003,36 (2),
215221.
(20) Yoshida, S.; Murata, H.; Imaida, M. Distribution of Pesticide
Residues in Vegetables and Fruits and Removal by Washing. Nippon
Nogei Kagaku Kaishi 1992,66 (6), 10071011.
(21) Cengiz, M. F.; Certel, M.; Karakaş, B.; Göçmen, H. Residue
contents of captan and procymidone applied on tomatoes grown in
greenhouses and their reduction by duration of a pre-harvest interval
and post-harvest culinary applications. Food Chem. 2007,100 (4),
16111619.
(22) Bajwa, U.; Sandhu, K. S. Effect of handling and processing on
pesticide residues in food- a review. J. Food Sci. Technol. 2014,51 (2),
201220.
(23) Sharma, J.; Satya, S.; Kumar, V.; Tewary, D. K. Dissipation of
pesticides during bread-making. Chem. Health Saf. 2005,12 (1), 17
22.
(24) Abou-Arab, A. A. K.; Abou Donia, M. Pesticide residues in some
Egyptian spices and medicinal plants as affected by processing. Food
Chem. 2001,72, 439445.
(25) Hasmukh, J.; Neha, T.; Praful, J. Effect of Household Processing
on Reduction of Pesticide Residues in Cauliflower (Brassica oleraceae
var. botrytis). Eur. J. Exp. Biol. 2012,2(5), 16391645.
Journal of Agricultural and Food Chemistry Article
DOI: 10.1021/acs.jafc.5b03327
J. Agric. Food Chem. 2015, 63, 85688573
8573

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Different combinations of Peelzym (I, II, III and IV) concentration (0.1, 0.55, 1cm3 enzyme/100cm3 solution), temperature (20°C, 35°C, 50°C), pH (3.0, 4.5, 6.0) and time (20, 40, 60min) were used for enzymatic peeling of apricots, nectarines and peaches. The optimum conditions were determined by using response surface methodology. Peeling yield, absorption of enzyme solution and texture changes were measured after peeling. For peeling of apricots with Peelzym IV, the optimum temperature was 45°C; the optimum values of time were in the range of 57–60min and that of pH and enzyme concentration were in the ranges of 3–3.5 and 0.85–0.90cm3 enzyme/100cm3 solution, respectively. Optimum conditions of peeling for nectarines were determined to be temperature, 44–47°C; time, 53–58min; pH, 3.5–4.1; and enzyme concentration, 0.70–0.90cm3 enzyme/100cm3 solution by using Peelzym I. For peaches the ranges were 41–46°C for temperature, 44–54min for time, 3.6–4.5 for pH and 0.73–0.90cm3 enzyme/100cm3 solution by using Peelzym IV. By this method, peeling was successful at moderately high temperatures.
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An extensive analysis of the headspace (HS) of coffee brew using proton-transfer-reaction mass-spectrometry (PTR-MS) is presented. In particular, we present a set of methods that link mass spectral peaks, as observed in PTR-MS, to chemical compounds in the HS of coffee. Combining all this information, a tentative assignment and rough quantification of liquid coffee HS is presented. Coffee was chosen because it contains a large number of chemically diverse volatile organic compounds (VOCs), representing a challenging system for on-line analysis by PTR-MS.