Extraction of protein from fresh rainbow trout (Onchorhynchus mykiss) viscera and smoked trout trimmings using commercial enzymes

In the current investigation, fresh trout viscera and smoked trout trimmings were enzymatically extracted using papain, alcalase, protamex, and flavourzyme. Protein extraction was performed at different concentrations (0.5%, 1%, 1.5% and 2%) and times (30 minute, 1 hour and 4 hours). The moisture, crude protein, lipid and crude ash contents of trout viscera used as raw materials, in the study, were respectively found as 60.26±0.78%, 12.18±0.21%, 31.18±0.36% and 1.33±0.07%, while these values in smoked trout trimmings were determined as 54.53±0.93%, 18.39±0.13%, 17.71 ± 1.06% and 8.50±0.13%, respectively. Following the conclusion of the study, protein content (g protein/100 g waste) and Protein Recovery Rate (PRR, %) in liquid protein hydrolysate extracted from trout viscera and smoked trout trimmings were found to be significantly affected by enzyme type, enzyme concentration, and extraction time. The results showed that the flavourzyme, followed by the protamex, produced the highest protein content (g protein/100 g waste) and PRR (%) in the liquid protein hydrolysate extracted from trout viscera. Furthermore, the protamex, followed by the flavourzyme, was shown to have the highest protein content (g protein /100 g waste) and PRR (%) in the liquid protein hydrolysate extracted from smoked trout trimmings.