Characterization and potential strategies for the valorisation of the Southwest Atlantic butterfish (Stromateus brasiliensis)

Graciela Ramilo-Fernández,Carmen G Sotelo

doi:10.1007/s13197-020-04332-6

Abstract

The waste of fish resources constitutes a serious environmental problem that must be avoided. The valorisation of by-catch species and decreasing the discard rate constitute a more efficient and sustainable use of these marine biomasses. In this work, we characterize and propose different potential uses for Stromateus brasiliensis, another frequently discarded (≥ 90%) and poorly studied by-catch species captured in the South Atlantic Ocean (FAO 41) by trawler fishing fleets. Furthermore, in the case of this species, freezing and frozen storage of the whole fish is the only strategy currently employed for its exploitation. The results revealed that muscle from S. brasiliensis presented a high content of polyunsaturated fatty acids (20.34%) and that the concentrations of both total diacyl glyceryl ethers (2.41%) and heavy metals (Hg 0.038, Pb 0.006 and Cd 0.018 mg/kg) were below the established limits for safe human consumption. Likewise, the protein hydrolysates proved to be a good source of amino acids for human consumption or animal feeding. Minced muscle blocks could be made by a mechanical separation process of the flesh, and the composition of minced muscle did not differ much from that of the whole fish. Furthermore, this process allows the incorporation of cryoprotectants and antioxidants to extend the frozen shelf life of this fatty fish. An extraction process from mechanically mixed skin and bones yielded a good source of collagen that should not be neglected.

Highlights

Increases in fish consumption and the demand for protein are rising due to population growth and changes in food habits
The results revealed that muscle from S. brasiliensis presented a high content of polyunsaturated fatty acids (20.34%) and that the concentrations of both total diacyl glyceryl ethers (2.41%) and heavy metals (Hg 0.038, Pb 0.006 and Cd 0.018 mg/kg) were below the established limits for safe human consumption
The present work demonstrates that undervalued fish species can be valorised using complementary processes, such as producing blocks of minced muscle, hydrolysing fish protein together with extracting collagen/gelatine to valorise the rest of the raw materials

Summary

Introduction

Increases in fish consumption and the demand for protein are rising due to population growth and changes in food habits. Consumers perceive fish as a healthy food. Fish are an excellent source of proteins, as well as healthy fats, vitamins and minerals, and are considered ‘‘nature’s superfood’’ (FAO 2017; Egerton et al 2017). Fish resources are not inexhaustible, and the current exploitation rates are unsustainable. In which a part of the catch is returned dead or alive to the sea for different reasons, are a global problem for the sustainability of fisheries. The last estimation of the discard rate in the world represents less than 10% of total annual catches, lower than previous estimations. The utilization of low-value or underutilized fishes and by-products is a way of increasing the supply of fish for food and other purposes without increasing the environmental impact

Methods

Results

Conclusion