Nile tilapia (Oreochromis niloticus) waste protein-based films

ABSTRACT

The demand for new materials and technologies that are able to minimize the environmental impact generated by the disposal of materials from fossil sources has increased significantly in the past years. As these materials normally include gelatin, a high cost ingredient, our aim was to find a more effective solution through the development of films based on protein isolate sourced from Nile tilapias. Thickness, water solubility, water vapor permeability (WVP), tensile strength, elongation, color attributes, and opacity were evaluated. Casting technique was used to obtain the films, using different combinations of protein isolate, gelatin, and plasticizers (glycerol or sorbitol) in an experimental design 2³. The films showed good continuity and handling. Surface was free from bubbles and cracks. Key results observed: thickness from 0.04 to 0.09 mm, solubility in water from 4.11 to 28.72%, WVP from 7.12 to 16.36 g mm d⁻¹ KPa⁻¹ m⁻², tensile strength from 12.43 to 155.57 MPa, and elongation from 2.14 to 125.33%. Gelatin protein films were promising from the point of view of mechanical properties, visual appearance and easy handling, as well as low WVP and low solubility in water. However, the replacement of gelatin in the formulations implicated in films with reduced tensile strengths.

KEYWORDS:

• Gelatin
• fish
• protein isolate

Acknowledgments

The authors gratefully acknowledge the Brazilian research funding agencies CNPq, CAPES and FUNDECT for the financial support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Cintia Granzotti da Silva Scudeler

Cintia Granzotti da Silva Scudeler has PhD degree in Biotechnology and Biodiversity (Federal University of Grande Dourados - UFGD) and researchers at the Bioenginering Research Group (BIOENG) of the UFGD.

Thayná de Lima Costa

Thayná de Lima Costa has bachelor’s degree in Food Engineering (UFGD) and researchers at the Bioenginering Research Group (BIOENG) of the UFGD.

José Ignácio Velasco

José Ignácio Velasco is full Professor and the Coordinator of the Polyfunctional Polymeric Materials Research Group (Poly2) at the Polytechnic University of Catalonia (UPC).

Farayde Matta Fakhouri

Farayde Matta Fakhouri is Associate Professor at UFGD and member of Poly2 group (UPC).

Gustavo Graciano Fonseca

Gustavo Graciano Fonseca is Associate Professor at UFGD and Coordinator of the BIOENG research group.