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 al., 2007).
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 fish.
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 and fish.
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.
Refrences
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 of cooking methods on the formation of heterocyclic aromatic amines of two different species of trout. Food chem., 104:67-72.
Pais,P., C.P. Salmon, M.G. knize and J.S. Felton,1999. Formation of mutagenic / carcinogenic heterocyclic amines in dry heated model systems, meat and meat drippings J.Agric. Food Chem., 47:1098-1108.
Sanz Alaejos, M., J.H. Ayala, V. Gonzalez and A.M. Alfonso, 2008. Analytical methods applies to the determination of heterocyclic aromatic amines in foods. J. Chem. B, 862: 15-42
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, pp:214-231.
