Evaluation of the chemical composition of protein concentrate and freeze-dried flours removed from pirarucu residues (Arapaima gigas)

Abstract

The pirarucu (Arapaima gigas) is considered one of the largest freshwater fish in the world. However, its processing generates large amounts of waste that can add value to the development of new products, generate income for the local population and also the possibility of spreading its consumption. Among the existing methods of dehydration, freeze-drying stands out for promoting greater preservation of the sensory and nutritional characteristics of foods. Protein concentrates from fish are products obtained by dehydration that have a high protein content. Its main characteristics are its high biological value, low cost and easy conservation. The objective of this work was to evaluate the physicochemical composition of protein concentrate and freeze-dried flour from pirarucu residues. The protein concentrate was obtained by modifying an existing methodology, with changes in the deodorization and delipidification steps. And freeze-drying using a benchtop freeze-dryer. In both methods, the head and carcass of Pirarucu were used, separately, in order to verify if there were significant differences (p ≤ 0.05) in all physicochemical properties evaluated. The freeze-drying process and obtaining the protein concentrate proved to be efficient alternatives for the use of pirarucu residues in the development of new products, as they reduced the moisture content (80.15% to 4.57%), as was the case with the minerals. (1.60% to 7.55%) and proteins (5.46% to 83.05%) and reduced the lipid content (20.97% to 6.87%).