C: Food Chemistry Effect of Storage Conditions on Lipid Components and Color of Mugil cephalus Processed Roes Antonella Rosa, Paola Scano, Angela Atzeri, Monica Deiana, Simone Mereu, and M. Assunta Dess` ı 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). Keywords: bottarga, cholesterol, Mugil cephalus, nonenzymatic browning, n−3 PUFA Practical Application: 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. Introduction Long-chain n−3 polyunsaturated fatty acids (n−3 PUFA) con- tained in edible fish and fish derivatives (oils and roe products) (Bledsoe and others 2003; Rubio-Rodriguez and others 2010) exert an important role on human health (Riediger and others 2009). These fatty acids are extremely sensitive to oxidation and other chemical changes by exposure to air, light, or heat, resulting in potential deterioration of food quality (Kolanowski and oth- ers 2007; Rubio-Rodriguez and others 2010). Lipid oxidation in fish products is responsible for changes in odor, flavor, color, tex- ture, and toxicity during manufacturing procedures and prolonged storage (Zamora and Hidalgo 2005; Kolanowski and others 2007). Several PUFA oxidative degradation products have been measured in fish derivatives such as lipid peroxides and secondary oxidation products (Refsgaard and others 2000; Boran and others 2006; Baron and others 2007; Kolanowski and others 2007). Fish roe products contain high levels of eicosapentaenoic acid (EPA, 20:5 n−3) and docosahexaenoic acid (DHA, 22:6 n−3) (Bledsoe and others 2003). Bottarga or botargo, the final product of a number of treatments (salting and drying) on the whole roe MS 20110861 Submitted 7/18/2011, Accepted 8/9/2011. Authors Rosa, Atzeri, Deiana, and Dess` ı are with Dipt. di Biologia Sperimentale, Sez. Patologia Speri- mentale, Univ. degli Studi di Cagliari, Cittadella Univ., SS 554, km 4.5, 09042 Monserrato, Cagliari, Italy. Authors Scano and Mereu are with Dipt. di Scienze Chimiche, Univ. degli Studi di Cagliari, Cittadella Univ., SS 554, km 4.5, 09042 Monserrato, Cagliari, Italy. Direct inquiries to author Rosa (E-mail: anrosa@unica.it). of mullet (Mugil cephalus), is considered a highly nutritive food having well-balanced proteins with essential amino acids and sig- nificant amounts of n−3 PUFA (Kalogeropoulos and others 2008; Scano and others 2008). In recent works (Scano and others 2008; Rosa and others 2009), we studied the major lipid classes and the fatty acid and alcohol composition of whole and grated bottarga samples manufactured in Sardinia. A high quantity of wax esters was found, followed by triacylglycerols, phospholipids, and choles- terol in its free and esterified forms; EPA and DHA amounted to 13% to 25% of total fatty acids (Scano and others 2008; Rosa and others 2009). We also evidenced in commercial bottarga samples a relatively high content of free fatty acids, due to hydrolysis pro- cesses induced by the manufacturing procedures, and appreciable levels of conjugated diene fatty acid hydroperoxides (HP), im- portant nonradical intermediates of PUFA peroxidation. Further- more, we studied the oxidative modifications of lipid components of mullet roe due to the salting and drying procedures usually adopted to obtain bottarga and n−3 PUFA oxidation in raw roes and cured products during storage at −20 ◦ C (90 d) and in the grated sample of bottarga at room temperature (32 d) (Rosa and others 2009). We showed that the treatments on mullet roe do not affect the lipid level (fatty alcohols and acids, cholesterol) and the concentration of HP. No significant difference was observed between n−3 PUFA levels during processing and at different stor- age conditions. The order of oxidative stability, as calculated by the HP determination, was: grated bottarga < whole bottarga < raw roe (Rosa and others 2009). A storage stability study was also performed on intermediate moisture mullet roe at various temperatures for up to 1 mo (Hsu and others 1983); chemical C  2011 Institute of Food Technologists R  doi: 10.1111/j.1750-3841.2011.02450.x Vol. 71, Nr. 1, 2012  Journal of Food Science C107 Further reproduction without permission is prohibited