Effect of Storage Conditions on Lipid Components and Color of Mugil cephalus Processed Roes

Abstract

The salted and semidried mullet (Mugil cephalus) ovary product (bottarga) is proposed as an important source of the long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid, and docosahexaenoic acid. In this work, we investigated the extent of lipid oxidation and browning of grated bottarga samples during 7 mo of storage at -20 °C, 2 to 3 °C in the absence of light, and at room temperature in the presence or absence of light. Modifications of the levels of total choline (as index of phospholipid breakdown), total sugars, and free amino acids such as lysine, methionine, and tryptophan (involved in nonenzymatic browning) were also studied at different storage conditions. Storage of bottarga did not significantly affect the n-3 PUFA and cholesterol levels with respect to the control; nevertheless, a significant hydroperoxide increase was observed during 7 mo in bottarga samples at all the storage conditions, while low malondialdeyde levels were measured. Samples placed at room temperature in the absence and in the presence of light showed over time a marked browning process, lipid breakdown, a sensible decrease in the levels of total sugars, tryptophan, and methionine with respect to control and samples stored at -20 °C and 2 to 3 °C. The resistance against the oxidation of the isolated bottarga lipids was also assessed in dry state at several temperatures (37, 75, and 140 °C). We evaluated the change in lipid compounds and color of dried and salted mullet roes under different storage conditions. The obtained results suggest the importance of the low temperatures to preserve the nutritional properties of this fish product during long storage.