Valorization of residues from anchovy (Engraulis anchoita) salting-ripening process: Impact of desalting procedures in retention of biologically-active compounds

Abstract

The salting-ripening of anchovy generates a large volume of residues that are discarded due to its high NaCl content. In this study, these residues are characterized and the suitability of desalination by immersion is assessed. Single-stage, using 0, 1, 3 and 5 %w/w NaCl solutions, and 3-stage (freshwater) desalting treatments were applied. The untreated residues presented a NaCl content of 17.6–55.9 g/100 g (%), with 12.8–14.8% of proteins and 2.4–3.5% of lipids. PUFAs fraction represented 9.8 and 20.3%, mainly comprised by EPA and DHA. 3-stage desalting treatment was more effective than the single-stage process for reducing NaCl content, reaching a final value of 1.6% in shorter time. The protein, lipids and PUFA final contents ranged from 9.4 to 14.2%, 3.8–5.0% and 15.7–20.9%, respectively, depending on the treatment performed. Protein retention percentages after desalting were greater than 65%. Non-significant lipid leaches were registered, and the proportion of fatty acid classes was not modified by the desalination processes applied. Our results show that salted anchovy residues present high proportion of nutrients that can be recovered through by-processing. Simple desalting process makes residues valuable to be reintegrated into different production cycles, such as fishmeal and oil production.