Effects of Antioxidants and Packing on Cholesterol Oxidation in Processed Anchovy during Storage

Abstract

Effects of added butylated hydroxyanisole (BHA) and tocopherols on oxidation of cholesterol during processing and subsequent storage of boiled and dried anchovy were evaluated by quantitative determination of constituent fatty acids and cholesterol oxides. Boiling and air-drying used for preparation of the sample yielded certain cholesterol oxides, including 7β-hydroxycholesterol, 7-ketocholesterol, cholesterol-5,6-α- and β-epoxides, cholestane triol and 25-hydroxycholesterol, even though BHA or tochopherols were added. As the levels of polyunsaturated fatty acids of the total lipids decreased, the levels of cholesterol oxides increased in all samples regardless of the presence of BHA or tocopherol. Formation of cholesterol oxides was controlled to some extent in the sample with added BHA. Tocopherols were also effective in controlling cholesterol oxidation, however they were less effective than BHA. Addition of BHA and tocopherols did not affect the rate of formation of cholesterol oxides in the early stage, up to 28 d of storage in air. The most effective method in controlling cholesterol oxidation was vacuum-packing of the sample with a metal-based oxygen absorber. For this sample, levels of cholesterol oxides after 156 d were similar to those of the control sample without added antioxidant stored in air for 14 d.