ABSTRACT
The objective of this study was to assess the exposure and
health risks associated with the consumption of kenkey by students of KNUST. Students
completed a food dietary questionnaire to gather their exposure frequency and
amount of kenkey eaten. Kenkey samples were collected from various students’
food joints and homogenized. Sirhan method of extraction and purification was
used to extract the aflatoxin from the kenkey. HPLC was used to determine the
concentrations of each group of aflatoxin. The probabilistic approach was used
to model the chronic exposures using the Monte Carlo simulation of the Palisade
@Risk software. The mean concentration of aflatoxin was 4.78 ng/g.
Probabilistic approach was used to estimate the chronic daily exposure. The
chronic exposures ranged between 0.024-1.09 ng/g bw/day. The chronic exposure
and reference dose of aflatoxin were used to estimate the hazard quotient. The
hazard quotient was below the tolerable limit (1). The chronic exposure for
both carcinogen and non-carcinogen groups of aflatoxins were also estimated of
exposure. There was a significant health concern as the margin of exposure
(792.06) for the carcinogen group was below the threshold level (10,000).
Aflatoxin contamination must be given a serious attention and effective
measures must be in place to curb the contamination of aflatoxin.
CHAPTER
ONE
1.0 INTRODUCTION
1.1 Background
Aflatoxins are mycotoxins primarily produced by Aspergillus
nomius, Aspergillus flavus and Aspergillus parasiticus. They are
known to be acutely toxic, mutagenic, carcinogenic, teratogenic and
immunosuppressive (Wild and Gong, 2009) and classified as G1, G2, B1 and B2
based on their chemical structures. Aflatoxins are found in most staple foods in
their raw forms such as maize (Murphy et al., 2006). Previous reports in
several studies have reported the occurrence of aflatoxins in foods from the
Ghanaian market (Khlangwiset et al., 2011). Out of the eighteen known
aflatoxins (AF), just AFG1 AFG2, AFB1 and AFB2 are reported in agricultural
food crops (Riba et al., 2010). Aflatoxin B1 is the only metabolite
among the four known groups that is very carcinogenic (Assunção et al.,
2018). The International Agency for Research on Cancer (IRAC) reported Aflatoxin
B1 is a hepato carcinogen when hazard is chronically exposed and causes acute
hepatitis and can end up causing cancer of the liver (IARC, 2002 and IARC,
2012). According to Assunção et al. (2018) aflatoxin B1 have been
grouped as class 1 potential carcinogen to humans.
Kenkey, which is a cereal-based
food, prepared from maize, is consumed by most Ghanaians and several studies
have reported the occurrence of aflatoxin in kenkey (Shephard, 2003). According
to Assunção et al. (2018), cereal-based foods is one of the commonest
means to human exposure to aflatoxin and other mycotoxins. Previous studies
have shown that approximately 25% of cereals produced globally are contaminated
by mycotoxins (FAO/WHO, 2002). Aflatoxin in maize is mostly produced as a
result of poor handling of maize in the supply chain including storage. If the moisture exceeds 12% and
humidity is not right, stored maize is prone to be contaminated with aflatoxin.
To be able to estimate the exposure and risk of aflatoxin in
kenkey, several methodologies such as dietary recall, and dietary history or
food-frequency methods are used. Assuming that the consumption of kenkey is
considered as chronic daily intake, dietary recall should be appropriate as it
could be expedient to recollect the exact food intake measurements (Cano-Sancho
et al., 2013). In order to make an accurate judgment on the risk that
aflatoxin in kenkey poses, it is imperative to take into consideration all
aspects risk indices. Risk characterization estimates the severity of an
identified hazard and the probable adverse health effects of the hazard
(Cano-Sancho et al., 2013). At the present time, the contamination
cereal-based foods by aflatoxin needs a close attention, specifically because
of the adverse health effects as a result of mycotoxins exposure could lead to
diverse toxicity and carcinogenicity (Speijers et al., 2004). Previous
studies only focused on the occurrence of aflatoxin and not much on exposure
and risk assessment especially in Ghana (Assunção et al., 2015). The
chemical compositions and knowledge of the toxicities of aflatoxin has been
used to envisage the toxicity and risk it presents. For example, in order to
quantify the risk associated with aflatoxin exposure, hazard quotient is used,
and it is expressed as the ratio of the chronic human exposures to the
reference dose of aflatoxin. On the other hand, margin of exposure (MOE), which
is defined as the ratio of bench mark dose lower limit (BMDL10) to estimated
exposure of a hazard. According to Syberg et al. (2008) these procedures
of risk assessment are based on the theories of Independent Action (IA)
and Concentration Addition (CA). According to Assunção et al. (2016),
MOE is aimed at both carcinogenic and genotoxic risk assessment and is mostly
used for the cumulative risk assessment. Lifetime risk is another way to
estimate risk of a hazard. It is multiplication of the potency factor and chronic daily intake that are exposed to
the population. The slope factor (also known as the potency factor) which is
the risk produced by a lifetime average dose of 1 mg/kg-day is mostly
originated from certified studies. Very few studies have been conducted on the
exposure and risk assessment exist on cereal-based products such as kenkey
Murphy et al., 2006). The European Food Safety Authority (EFSA)
instituted a minimum limit of 5 µg/kg for total aflatoxin in cereals (van
Egmond et al., 2007). The objective of this study was to estimate the
exposure and risk associated with aflatoxin exposure through the consumption of
kenkey.
1.2 Problem
Statement and Justification
As a result of the high standard of living on university
campuses in Ghana, many students resort to consuming cheaper food alternatives
such as cereal-based (kenkey). However, there have been documented evidence of
poor handing of cereals on the market especially if the grains are not sourced
from certified maize grits producers (Shephard, 2003). Thus, it can be assumed
that consumers of these cereal-based foods are at risk of adverse health
effects that result from aflatoxin known to be present in the poorly handled
grains as a result of the growth of Aspergillus flavus. Therefore, there
is the need to quantify the exposure and determine if the concentrations
of aflatoxins in kenkey consumed by many students on KNUST campus are enough to
pose a significant health concern or risks such as cancers or any related
toxicities. Since reports from the KNUST Hospital indicates increasing number
of students who are treated of Hepatitis B.
1.3 Main Objective
To
estimate the dietary exposure and health risks associated with the consumption
of kenkey.
For more Food Science & Technology Projects Click here
===================================================================Item Type: Ghanaian Topic | Size: 35 pages | Chapters: 1-5
Format: MS Word | Delivery: Within 30Mins.
===================================================================
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.