67D-14 |
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G. R. Sampaio, D. H. Bastos, R. A. Soares, and E. A. TORRES. Department of Nutrition School of Public Health, University of São Paulo, Av. Dr. Arnaldo, 715 HNT, São Paulo SP, 01246-904, Brazil Foods submitted to technological processes that require high temperatures present a great potential for production of cholesterol oxides (COPs), deserving for that the corresponding attention. In sea food the cholesterol oxidation is favored by the presence of unsaturated fatty acids and high levels of cholesterol, therefore, a great potential for the formation of cholesterol oxides. Sea food are relatively little studied. Moreover, numerous reviews have been written and have demonstrated that the several cholesterol oxides are potentially cytotoxic, atherogenic, mutagenic, carcinogenic and other undesired biological effects. In this study, we describe the quantitative determination of COPs in popular Brazilian salted and dried shrimp HPLC was employed in the analysis of COPs in salted and dried shrimp. Cholesterol and four COPs could be analyzed simultaneously incluinding (7betha-hydroxycholesterol, 7alpha- hydroxycholesterol, 7-Ketocholesterol and 25- hydroxycholesterol). Fifty samples in four lots of salted and dried shrimp were analyzed. Total lipids analysis was performed by the dry column; fatty acids were determined by gas chromatography and lipid oxidation was assessed by the 2-thiobarbituric acid method (TBARs). The results showed that the samples examined contained: 7betha-OH (34.63-72.56 ug/g), 7alpha-OH (5.02-12.12ug/g), 7-Keto (7.44-32.68 ug/g) and 25-OH (2.37-22.88 ug/g) with 7betha-OH appearing as the predominant product. The amount of COPs in the analyzed samples varied considerably, ranging from 4.52 to –77.29 ug/g). The total cholesterol content ranged from 73.88 to 247.69 mg/g, while the thiobarbituric acid (TBARs) values ranged from 0.023 to 1.30 mgMA/Kg of sample. Fatty acids profiles showed an average of 27.48 % saturated, 43.90 % monounsaturated and 28.61 % polyunsaturated. The results showed that the salted and dried shrimp samples were oxidized and presented COPs. The processing and storage conditions might be the primary factors for the formation of COPs in salted and dried shrimp, since these samples had been kept under abusive storage conditions.
Session 67D, Food Chemistry: Lipid and carbohydrate chemistry
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