Comparative Study on Total Lipid Quantification and Oxidative Rancidity Determination in Freshwater Fish Species with Different Fat Levels

Abstract

<p>The aim of this study was to investigate the efficiency of different extraction methods for total lipid determination and oxidative rancidity evaluation in freshwater fish with different fat levels. Total lipid content was determined by Bligh and Dyer with slight modifications and Soxhlet methods. Malondialdehyde (MDA) quantification was determined by analytical methods with and without heat application. In both freshwater fish species, Bligh and Dyer method extracted greater total lipid content (<em>P</em> <0.05) than Soxhlet method. In addition, the heat method revealed higher MDA values (<em>P</em> <0.05) compared to cold method in both lean fish (<em>Cichla ocellaris</em>) and high-fat fish species (<em>Piaractus brachypomus</em>). We concluded that, regardless of the fat content in the freshwater fish species, the Bligh and Dyer method and the cold method used for oxidative rancidity were more efficient than Soxhlet method and heat technique, respectively.</p>