EVALUATION OF PROCESSING, PRESERVATION AND CHEMICAL AND FATTY ACID COMPOSITION OF NILE TILAPIA WASTE

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.