Bioactive Properties of Fish Protein Hydrolysates from Amazon Sailfin Catfish (Pterygoplichthys pardalis) from the Victoria Reservoir in Sri Lanka

S K D Wijesinghe,E D N S Abeyrathne,J K Vidanarachchi,R P N P Rajapakse

doi:10.4038/tar.v32i2.8469

Abstract

Pterygoplichthys pardalis is an underutilized by-catch fish species considered as an invasive fish, which is a potential threat to Sri Lankan freshwater fishery industry. This study attempted to produce bioactive fish protein hydrolysates (FPH) using P. pardalis. Acid-aided aqueous extract of fish protein was produced and the best protein extraction (PE) was selected. The lyophilized extracts were hydrolyzed using pepsin, papain and trypsin enzymes (1:100), and were subjected to analyze antioxidant properties by DPPH scavenging assay and TBARS assay, metal chelation activity and antimicrobial activity by agar well diffusion method. The 15% citric acid sample showed the highest (p<0.05) PE yield (1.95%±0.04 w/w). The pepsin (0 hour) treated hydrolysate showed the highest (p<0.05) radical scavenging activity (79.71%±5.19). None of the hydrolysates exhibited antioxidant properties against TBARS and showed no significant difference (p>0.05) in the ferrous chelating activity (pepsin (0 hour): 52.31%±0.93, papain (9 hours): 50.95%±1.17). Antibacterial activity against E. coli was positive in all hydrolysates, where pepsin (0 hour) hydrolysate showed the highest activity against E. coli. This concludes, FPHs of acidsoluble protein of P. pardalis contain antioxidant properties, iron-binding activity and antibacterial activity.

Highlights

Fish is a highly nutritious food, which has a high demand among consumers (Ojutiku et al, 2009)
In acid-aided solubilization of fish protein, typically HCl or H2SO4 is used. This could lead to significant loss in its functional properties over the alkali-aided solubilization and leave health concerns (Kristinsson and Rasco, 2000)
The lowest yield was observed in the control (0% citric acid) sample though there was no significant difference of the yield between control and 5% citric acid contained samples, whereas, the highest yield was observed in 15% citric acid contained sample

Summary

Introduction

Fish is a highly nutritious food, which has a high demand among consumers (Ojutiku et al, 2009) It is a rich source of balanced and digestible protein sulphur containing amino acids, omega-3 long chain polyunsaturated fatty acids, vitamins and a low caloric density food compared to terrestrial animal meat (Tacon and Metian, 2013). It provides about 15% of the average per capita intake of animal protein of more than 4.5 billion consumers (Béné et al, 2015). Such value-added products include fish protein hydrolysates, pet food, fish silage, fertilizer, fish oil etc. (Ramírez-Ramírez et al, 2008)

Methods

Results

Conclusion