Portugal: Coimbra researchers develop edible packaging from food waste

A team of researchers at Portugal’s University of Coimbra, working with colleagues at the Coimbra Agriculture School (ESAC), has developed edible packaging from waste from the food processing and fisheries sectors, the university announced on Monday.

The edible packaging, which is described as “a sustainable alternative to plastic” takes the form of “films obtained from waste from different foods, including potato and quince peelings, fruit outside standardised characteristics and crustacean shells,” reads a statement from the university.

“In addition to coating the food, prolonging its shelf life on the supermarket shelf,” it said, the packaging “can also be ingested.”

The new packaging created by Marisa Gaspar, Mara Braga and Patrícia Almeida Coimbra of the Research Centre for Chemical Process Engineering and Forest Products of the Faculty of Science and Technology of the University of Coimbra (FCTUC) were developed “essentially to coat fruits, vegetables and cheeses, incorporating in its matrix bioactive/nutraceutical compounds, such as antioxidants and probiotics, with potential beneficial effects on health.”

With this packaging it is possible, for example, “to cook broccoli or asparagus without having to remove the packaging, as the film that surrounds them is composed of natural nutrients with health benefits,” the statement says. “We produce differentiated film compositions, using the waste almost entirely, which contain compounds with different properties.

“Potato peel has more starch and quince peel more pectin, that is, we have two structural polymeric materials that, when combined, will generate a simple film, without complex processing,” the researchers are quoted as saying.

However, before obtaining the wrappings, either in the form of film, or in the form of a spray – to be applied in liquid form and which then dries on the food – the team had to overcome several stages.

“The biggest challenge is finding the ideal materials so that the formulations have the desired characteristics,” they note, stressing that it was necessary “to study the films from the physical point of view, such as mechanical properties, in order to serve as packaging / coating; study the bioactive properties of films, i.e. if some compounds have health benefits when ingested; evaluate the reactions when different compounds are joined.”

In addition, a microbiological and sensory analysis was carried out on selected films to “evaluate the compatibility of food with the produced edible system,” the statement quotes the three researchers as saying.

The solution, they argue, may be “very advantageous both for the industry and for the consumer.

“It is an approach focused on the circular economy,” they state. “It not only increases the shelf life of the product, but also avoids waste, reduces the production of plastic waste, a serious environmental problem, and generates a new product that gives a nutritional additional to the food.”

Started in 2018 as part of the MultiBiorefinery project, with money from Portugal’s COMPETE 2020 programme, which draws on European Union development funds, this research was recently awarded a prize of €20,000 by the programme Seed Projects for Interdisciplinary Research – Santander UC, which is awarded to multidisciplinary teams led by young researchers at the University of Coimbra.

It was also awarded a prize in the LL2FRESH ideas competition, which aims to find new packaging solutions, food treatment methods and state-of-the-art additives, according to the university.

As part of the project, a scientific article was published in the journal ‘Food Packaging and Shelf Life’