Cholesterol oxidation results in the production of oxides that exert a wide range of biological activities such as atherosclerosis, mutagenesis, carcinogenesis and citotoxicity. During cooking foods are exposed to oxygen, heat and other factors that can promote lipid oxidation, including cholesterol oxidation. Because of the presence of polyunsaturated fatty acids and the high levels of cholesterol crustaceous have a great potential for oxide production. 7-ketocholesterol has been used as a "tracer" of the degree of cholesterol oxidation, due to its fast and continuous formation and thus relatively high amounts with respect to the other oxidation products. The objective of this work was to evaluate the effects of boiling and deep-frying on the cholesterol oxidation in pink-shrimp (Penaeus brasiliensis and Penaeus paulensis). Cooking of pink-shrimp, in general, decreased both free cholesterol and 7-ketocholesterol concentrations. Such decrease was higher after frying than after boiling and was more pronounced for 7-ketocholesterol. While the cholesterol concentrations were 10.7 and 24.7% lower, the decrease of 7-ketocholesterol concentrations was 41.5 and 61% in boiled and fried shrimp, respectively. The reduction of free cholesterol and 7-ketocholesterol concentrations in processed pink-shrimp was related to elution of these compounds by the cooking medium, i.e. water in boiling and oil in frying.
cholesterol; oxidation; 7-ketocholesterol; shrimp; boiling; frying
