INTRODUCTION
Aflatoxins display an insufficiently recognized risk to human health. They
are formed in stored nuts, cereals and rice under high humidity and temperature
conditions (Peraica et al., 1999). They can be
found in a variety of food items and since they are heat-stable, they can not
be destroyed by normal industrial processing or cooking (MaCdonald
and Castle, 1996; Creepy, 2002).
Aflatoxins are a group of closely related heterocyclic compounds produced predominantly
by two filamentous fungi, Aspergillus flavus and Aspergillus parasiticus.
Recent studies have shown that some A. nominus and A. tamarii
starins are also produce aflatoxin (Mishra and Das,
2003). Ito et al. (2001) isolated
one more strain, A. pseudotamarii that can produce aflatoxin.
Aflatoxins contaminate a vast array of food and agricultural commodities. Aspergillus species are capable of growing on a variety of substrates and under a variety of environmental conditions.
Therefore, most foods are susceptible to aflatoxigenic fungi at some stage
of production, processing, transportation and storage (Mishra
and Das, 2003). Presently, 18 different types of aflatoxins have been identified
with aflatoxin B1, B2, G1, G2, M1 and M2 being the most common. Of these, Aflatoxin
B1 (AFB1) and G1 (AFG1) occur most frequently. Biological effects of aflatoxin
can be subdivided into its toxicity, carcinogenicity, mutagenicity and teratogenicity.
The effects are influenced by species variation, sex, age, nutritional status
and effect of other chemicals. In addition, the dose level and period of exposure
of the organism to the toxin are very important (Mishra
and Das, 2003).
AFB1 is the most abundant and toxic form of all naturally occurring aflatoxins.
AFB1 represents 75% of all aflatoxins found in contaminated food and feeds.
It is hepatotoxic, hepa-tocarcinogenic and teratogenic to various animal species.
The formation of AFB1-DNA adduct is highly correlated to the carcinogenic effect
of AFB1 in both animal and human cancer cases (Ayub and
Sachan, 1997).
Aflatoxicosis characterized by jaundice, ascites, portal hypertension and other
signs of hepatic failure has been described in humans exposed to 2-6 mg of aflatoxin
daily for approximately 1 month after consumption mold damaged-corn. Immunosuppression
caused by aflatoxins has been demonstrated in laboratory animals, although virtually
no data are available on the immunosuppressive effects of aflatoxins in human
populations (Eaton and Gallagher, 1994).
In this respect, aflatoxin contamination in spices is important for the public health. In current study, total aflatoxin levels in spices was detected (red pepper, black pepper, cumin and flaked red pepper) that were obtained from West Mediterrenian region of Turkey.
MATERIALS AND METHODS
Samples: A total of 134 spice samples that were obtained from bazaars
and markets in Burdur, Isparta and Antalya city centers were evaluated in the
experiments. These spices were black pepper, powdered red pepper, cumin and
flaked red pepper.
Aflatoxin assays: Helica Biosystems MycoMonitor Total Aflatoxin ELISA kit (Helica Biosystems Inc. Fullerton, CA. USA) was used for quantitative detection of total aflatoxin in the samples following manufacturer’s instructions. The microwells were measured at 450 nm by an ELISA reader. The optical densities of the samples were compared with the OD’s of the kit standarts and an interpretative result was determined.
Spice samples were exposed to some pretreatments. About 20 g of the spice sample was mixed with 100 mL of 70% methanol in a beaker for 2 min. Mix was filtrated by a filter paper. This filtrate were used in the above mentioned assay.
RESULTS AND DISCUSSION
Total Aflatoxin levels of the spices that evaluated in this study were shown
in Table 1. Total aflatoxin values of the samples not exceeded
10 μg kg-1 as legal limit of the European Union. All of the
red pepper samples were contaminated with levels ranging from 3.55-9.55 μg
kg-1. Black pepper samples contained levels ranging from 0.67-6.15
μg kg-1. Cumin aflatoxin levels were found to be ranging from
4.55-8.57 μg kg-1 while flaked red pepper contained aflatoxin
levels maximum 9.46 μg kg-1. Insufficient hygiene conditions
during drying, transport and storage stages in the production of red pepper
could cause microbiological and mycological growth which could result in the
formation of mycotoxins (Aydin et al., 2007).
In a similar study in ground deep-red pepper samples from Sanliurfa (Turkey),
72 of the 75 samples (96%) contained AFB1 in the range of 0.11-24.7 μg
kg-1. Eleven (14.7%) samples were above the regulatory limits used
in the European Union and in Turkey (Ardic et al.,
2008). Aydin et al. (2007) evaluated Aflatoxin
B1 levels in 100 red pepper samples that randomly obtained from Istanbul
markets.
| Table 1: |
Total aflatoxin levels of the spices |
 |
|
According to the results, values of 32 samples were below the minimum detection
limit in 50 samples were between 0.025 and 5 μg kg-1 and 18
samples had unacceptable contamination levels higher than the maximum tolerable
limit (5 μg kg-1) (Aydin et al.,
2007). Bircan (2005) evaluated 75 spice samples
marketed in Turkey. According to results, 27 paprika all the chilli powder and
four ground black pepper samples were contaminated with aflatoxin B1
in the range of 0.5-116.4, 1.6-80.4 and 0.3-1.2 μg kg-1, respectively.
About 23 paprika and chilli powder samples were above the regulatory limits
used in the European Union. Aflatoxin contamination was not detected in the
cumin samples (Bircan, 2005).
Colak et al. (2006) were randomly obtained 84
samples of spices (30 red-scaled pepper, 30 red pepper and 24 black pepper)
from Istanbul markets and bazaars. They reported that 17 out of 30 red-scaled
pepper samples (56.7%) contained total aflatoxins ranging from 0.7-46.8 μg
kg-1 while 13 out of 30 samples contained AFB1 ranging from 1.9-35.5
μg kg-1. In red pepper, 11 out of 30 samples (36.7%) contained
total aflatoxins ranging from 0.8-15.4 μg kg-1. The concentrations
of AFB1 were found to be ranging from 2.9-11.2 μg kg-1.
The levels of total aflatoxins were determined to be ranging from 0.3-16.7
μg kg-1 in 8 out of 24 black pepper samples. Only two samples
contained AFB1 at the levels of 9.8 and 10.3 μg kg-1 (Colak
et al., 2006). Erdogan analysed 44 red-scaled pepper and 26 red
powder pepper samples obtained from various spice retailers in Erzurum and 20
isot (red pepper produced in Sanliurfa) were investigated for aflatoxin contamination
using thin layer chromatography. Aflatoxin (B+G) was found in 8 red pepper samples
(18.2%) and 3 red powder peppers (10.7%) and 1 isot sample (5%).
The aflatoxin amount ranged from 1.1-97.5 ppb in all samples investigated.
The highest amount of aflatoxin was found in red-scaled pepper (Erdogan,
2004). However, aflatoxin levels of spices in Europe are varied in different
countries. In a study that achieved in Lisbon (Portugal), 79 prepackaged samples
of 12 different types of spice powders (5 cardamom, 5 cayenne pepper, 8 chilli,
5 cloves, 7 cumin, 5 curry powder, 5 ginger, 5 mustard, 10 nutmeg, 12 paprika,
5saffron and 7 white pepper) were analysed. AFB1 was detected in 34 samples
of prepackaged spices (43.0%). All of the cayenne pepper samples were contaminated
with levels ranging from 2-32 μg kg-1. About 3 nutmeg samples
contained levels ranging from 1-5 μg kg-1, 3 samples had levels
ranging from 6-20 μg kg-1 and there were two with 54 and 58
μg kg-1. Paprika contained levels of aflatoxin B1 ranging from
1-20 μg kg-1. Chilli, cumin, curry powder, saffron and white
pepper samples had levels ranging from 1-5 μg kg-1. Aflatoxins
were not detected in cardamom, cloves, ginger and mustard (Martins
et al., 2001). Romagnoli et al. (2007)
reported that only 7 of 103 spices that collected from Emilia Romagna Region,
Italy were aflatoxin positive.
CONCLUSION
Aflatoxins can be found in a variety of food items and since, they are heat-stable,
they can not be destroyed by normal industrial processing or cooking (Creepy,
2002; MaCdonald and Castle, 1996). Hygiene and storage
conditions should be ameliorated for the prevention of aflatoxin contamination
in spices. According to Mishra and Das (2003) most rational
and economic approach is preharvest elimination of aflatoxin. Prevention of
aflatoxigenic fungal attack is possible by using healthy seeds, proper irrigation,
rotation of crops, harvesting after full maturity, drying the harvested crops
within time and store them under proper atmosphere, preventing insect or other
damages to the crop (Mishra and Das, 2003). However,
according to some researchs, ozone application may presents a solution for aflatoxin
contamination problem (Inan et al., 2007; Akbas
and Ozdemir, 2006).
