1.1 Background to the Study
Heterocyclic amines are compounds that
are formed naturally during cooking of proteinaceous foods such as meat
and fish. Various heterocyclic amines can be formed upon heating of
especially fish or meat in oils and fats and is sometimes called
harmburger carcinogen. Epidemiologic studies have shown that most
heterocyclic amines are highly mutagenic (Felton et al., 1984) and aost
all of them are also carcinogenic (Sugimura, 1995). The concentration of
heterocyclic amines depend on meat type, cooking procedures, pH, water
activity, carbohydrate, free amino acids, creatinine, heat and mass
transfer, lipid, lipid oxidation, antioxidants (Felton et al.,
1997;Jagerstad et al., 1998; Paid et al., 1999; Oz and Maya 2006; Oz et
There is an extensive literature on the
preacence of heterocyclic amines in meats cooked at high temperature,
but in many of the reported studies the cooking was not well described,
analysis method varies and might not be comparable, or samples were
cooked to maximise the production of heterocyclic amines and not to be
representative of the way meats are usually cooked by the general
population in Nigeria. The systematic measurement of heterocyclic amines
values in most commonly consumed meat types cooked by representative
practices are needed to accurately assess heterocyclic amine exposure in
epidemiological studies in Nigeria.
Meat and fish are widely consumed in
Nigeria and is likely to be one of the main contributors to heterocyclic
amine exposure. Exposure to heterocyclic amine varies depending on the
cooking technique and the degree of doneness. In this study heterocyclic
amine content of some of the most commonly consumed cuts of meat and
fish cooked by different methods to varying degrees of doneness will be
reported. This study also aim to investigate the effects different of
different cooking methods (microwave, oven, hot plate, pan frying and
barbecuing ) and cooking levels of doneness ( rare,medium, well and very
well) on the formation of heterocyclic amines in cu nks of meat and
1.2 Problem Statement
It has been stated that human exposure
to heterocyclic amines is influenced not only by the type of food and
cooking method but also by portion size and intake frequency
(Skog,2004). Hence, there is need to determine the effects of cooking
techniques and levels of the formation of heterocyclic amines in meat
1.3 Objectives of the Study
The major objective of the study is to
evaluate the effects of cooking techniques and level of formation of
Heterocyclic amines in meat and fish.
1.4 Research Questions
(1) what are heterocyclic amines?
(2) what type of food can they be found ?
(3) what are the factors that can influence their formation ?
(4) what are the types of cooking techniques to be employed ?
1.5 Significance of the Study
This study gives a clear insight into
the effects of cooking techniques and levels on the formation of
heterocyclic amines in meat and fish. The findings and reendations of
this research will help consumers be aware of the hazard associated with
consumption of meat and fish and necessary safety steps to consider.
1.6 Scope of the study
The research focuses on the effect of
cooking techniques and levels on the formation of heterocyclic amines in
meat and fish in Nigeria.
Felton J.S., M.G.knize, C Wood, B.J.
Wuebbles and S.K. Healey et al., 1984. Isolation and characterization of
new mutagens from fried ground beef. Carcinogenesis, 5: 95-102.
Felton J.S.,E. Fultz, F.A. Dolbeare and
M.G. knoze, C.P. Salmon, E.C. Hopmans and R.W.Wu, 1097. Health risks of
heterocyclic amines. Mutant. Res,., 376: 37-41.
Jagerstad, M., K. Skog, P. Arvidsson and
A. Solyakor 1998. Chemistry; formation and occurrence of genetoxic
heterocyclic amines identified in model systems and cooked foods. Z.
Lebensm. Unters Forsch A.,207:419-427.
Oz, F. and M.Maya, 2006. Mutagenic and carcinogenic heterocyclic aromatic amines FEBSJ.,273:77-367.
Oz, F.,G. Kaban and M.kaya,2007. Effects
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two different species of trout. Food chem., 104:67-72.
Pais,P., C.P. Salmon, M.G. knize and
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Food Chem., 47:1098-1108.
Sanz Alaejos, M., J.H. Ayala, V.
Gonzalez and A.M. Alfonso, 2008. Analytical methods applies to the
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Skog, K.,2004. Blue cotton, blue rayon
and blue chitin in the analysis of heterocyclic aromatic amines- A
review J. Chromatogr. B, 802:39-44.
Sugimura, T.S.,1995. History, present
and Future of Heterocyclic Amines, cooked Food Muyagens. In :
Heterocyclic Amines on cooked Foods: possible Han Carcinogens, Adamson,
R.H. (Ed). Princeton Scientific Publishing Co., Princeton, New jersey,