RESUMOEspinhaços de tilápias (Oreochromis niloticus) são partes do peixe de composição desconhecida. A composição lipídica dos espinhaços não é citada na literatura, bem como a estabilidade da farinha do espinhaço durante o armazenamento. Nesse sentido, realizou se estudo de processamento dos espinhaços envolvendo etapas de cocção, trituração, secagem, peneiramento e armazenamento da farinha. A farinha ficou armazenada sob refrigeração por um período de 90 dias, sendo sua qualidade monitorada por meio da composição em ácidos graxos, índice de acidez e análises microbiológicas. Os resultados da composição centesimal foram de 14,2% (umidade), 40,8% (proteína), 18,3% (resíduo mineral fixo) e 25,3% de lipídios totais. Nos lipídios totais foi identificado um total de 24 ácidos graxos, com predominância dos ácidos graxos (porcentagem média) de 27.4% (ácido palmítico, 16:0), 35,15% (ácido oléico, 18:1n-9) e 11,82% (ácido linoléico, 18:2n-6) e, em menor proporção: 0,88% (ácido alfa-linolênico, 18:3n-3), 0,08% (ácido eicosapentaenóico, 20:5n-3) e 0,59 (ácido docosahexaenóico, 22:6n-3). Durante os 90 dias de armazenamento, foram observadas algumas alterações no índice de acidez e composição de alguns ácidos graxos, no entanto, para 60 dias de armazenamento, não foram observadas alterações na composição de nenhum ácido graxo, do índice de acidez e nas análises microbiológicas.Termos para indexação: Tilápia, farinha, espinhaço, ácidos graxos, armazenamento. ABSTRACTThe composition of the tilapia (Oreochromis niloticus) fishbone is unknown. Lipid composition fishbone is not cited in the literature, and neither is the stability of the flour of the fishbone during storage. We studied the processing of fishbone cooking, grinding, drying, sieving and the storage of the flour. The flour was stored in a refrigerator for a period of 90 days, and its quality was monitored through fatty acid composition, acid index and microbiology control. The results of the proximate composition were of 14.2% (moisture), 40.8% (protein), 18.3% (ash), and 25.3% total lipids. In the total lipids identified 24 fatty acids were identified, with predominance of the fatty acids (medium percentage) of 27.4% (palmitic acid, 16:0), 35.15% (oleic acmid, 18:1n-9) and 11.82% (linoleic acid , 18:2n-6) and, in smaller proportion: 0.88% (alpha-linolenic acid, 18:3n-3), 0.08% (eicosapentaenoic acid, 20:5n-3) and 0.59 (docosahexaenoic acid, 22:6n-3). During the 90 days of storage some alterations were observed in the acid index and composition of some fatty acids, however, for 60 days of storage no alterations were observed in the fatty acids composition, acid index, and microbiology control.

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In this experiment, the heads of Nile tilapia were used as a raw material to produce flour through cooking, grinding, drying and sieving processes. The flour obtained was stored for 90 days in a refrigerator and shelf time was monitored by chemical methods (acid number [AN] and thiobarbituric acid [TBA] test), fatty acid composition and microbiological methods. The proximate composition was: moisture (6.01%), ash (19.38%), proteins (38.41%) and total lipids (35.46%). Thirty‐six fatty acids were found in the lipidic fraction. The predominant ones were 16:0, 18:1n‐9 and 18:2n‐6. The fatty acids of the series n‐3, 18:3n‐3 (alpha‐linolenic acid), 18:2n‐6 (linolenic acid), 20:5n‐3 (eicosapentaenoic acid) and 22:6n‐3 (docosahexaenoic acid) were found in smaller proportion. No changes were detected in the flour stored for 90 days as to polyunsaturated fatty acids and microbiological analysis. The AN remained constant up to 60 days of storage and TBA values increased throughout the 90‐day storage. PRACTICAL APPLICATIONS Waste Nile tilapia heads are not commonly used in human feeding and, therefore, are discarded. In this experiment, Nile tilapia heads were used as a raw material to produce tilapia flour; it was stored in a refrigerator and the shelf time was monitored for 3 months by chemical and microbiological methods. The flour is a caloric food, has high lipid content with omega‐3 fatty acids, minerals, proteins and can be used as human feeding.

Fish from the Amazon Basin are affected by oscillations in the river water volume, which influences the diet of animal species. This study was aimed at evaluating seasonal variations in lipid content, fatty acid composition and nutritional profiles of five fish species from the Amazon Basin. The lipid contents of all fish species were observed to be lower in flood periods than in drought periods; Brachyplatystoma flavicans showed the largest variation (6.75–15.43 %) between these periods, while Colossoma macropomum showed no significant difference (p > 0.05). The fatty acid composition in the five fish species varied throughout seasonal periods; saturated fatty acid (SFA) contents decreased in flood periods, whereas polyunsaturated fatty acid (PUFA) contents significantly (p < 0.05) increased for all the species in the same period. Leporinus friderici showed the highest content of α‐linolenic acid, (LNA 14.86 mg g−1) and Colossoma macropomum presented the highest content of docosahexaenoic acid (DHA 26.13 mg g−1) in flood periods. Prochilodus nigricans showed the lowest content of arachidonic acid (AA) in both periods, while Brachyplatystoma flavicans showed the greatest amount of AA, 18.77 mg g−1 in drought period and 22.10 mg g−1 in flood period. All the fish species presented favorable indices of nutritional quality of lipid fraction, suggesting that consumption of these species could be considered beneficial to human health.

This study evaluated the fatty acid composition and the nutritional profile of Brycon cephalus and Brycon microlepis, fish species from the central Amazon basin, by different methods of quantification. The methods applied were: area normalization (MAN), internal standard (MIS), alternative theoretical (MAT) and alternative experimental (MAE). Significant differences were observed between the methods applied and the species studied. MAN supplied poor information about fatty acids composition and diet formulation, presenting only fatty acid profiles. MIS, MAT and MAE supplied fatty acids composition information on a mass basis. MAT and MAE overestimated results, whereas MIS presented the most accurate results. B. cephalus and B. microlepis showed high contents of approximately 65 mg g-1 of n-3 fatty acids. Eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) content totaled, 104.37 mg 100 g-1 and 117.89 mg 100 g-1 for B. cephalus and B. microlepis, respectively. The nutritional profile of both fish species showed favorable indices for nutritional quality of the lipid fraction, indicating that both Brycon species are healthy dietary choices.