Amazonian fish-skin biofilm offers a sustainable alternative to plastic packaging film

Brazilian researchers are moving fish-processing waste one step closer to a packaging-grade material. A team from the University of São Paulo (USP) and EMBRAPA Pecuária Sudeste has developed a transparent, flexible gelatin biofilm made from the skin of tambatinga, an Amazonian farmed hybrid fish. The concept is straightforward: upcycle collagen-rich skins into a biodegradable film that could partially replace petroleum-based packaging films used to protect dry foods.

From a packaging perspective, the project focuses on the performance package that matters most for thin films: mechanical integrity, barrier behavior and optical properties. The researchers extracted gelatin from cleaned skins via a hot water–acid process (using acetic acid), with an extraction yield reported at 35.5% and gel strength around 263.9 Bloom, figures that support film-forming potential. They then cast films with glycerol as a plasticizer. By changing glycerol level, they could tune the film’s strength–flexibility balance: tensile strength decreased from 59.4 to 37.9 MPa, while elongation at break increased from 116% to 159.1%. That’s relevant for pack formats that need both toughness and fold/tear resistance during converting and handling.

Barrier and light protection are where this material looks particularly interesting. The films showed excellent UV blocking below 300 nm while remaining highly transparent in the visible range: an attractive combination for brands that want product visibility but also need protection for photosensitive ingredients (e.g., oils, vitamins, nuts). The study also reports lower water vapor permeability than many other gelatin-based films, suggesting potential for dry and semi-dry applications where moisture control is a key shelf-life driver.

The limitation is equally packaging-specific: humidity sensitivity. Like many protein-based biopolymers, the film absorbs moisture, which currently restricts use to dehydrated products such as nuts and chestnuts. In practical terms, that points to near-term use cases such as inner wraps, sachets, or coatings in multilayer structures where a moisture-resistant outer layer can shield the biofilm while it contributes stiffness, UV shielding or bio-based content.

For packaging developers, the next milestones are clear: scaling extraction with consistent quality, validating food-contact compliance, and improving water resistance (for example via blends, crosslinking or lamination/coating strategies). Supported by São Paulo Research Foundation (FAPESP) via the Food Research Center (FoRC), the work illustrates how bio-based films can be designed around specific packaging functions (not just “compostability”) while creating a circular outlet for aquaculture residues.

Written by Anina Dorizzi. Posted on Packaging Post.