Algae are already used by industry as a source of raw materials for stabilisers or thickening and gelling agents. However, they are also suitable as a source of carbohydrates for bioplastics. Thanks to their additional properties, they can help to extend the shelf life of packaged foods.
The EU research project BIOCARB-4-FOOD with the participation of the University of Hohenheim is now looking for new, sustainable packaging materials made from algae and seaweed. „We are looking for alternative natural resources such as algae and marine plants. Not only because they are available in abundance, but also because they offer a Large number of potentially interesting connections “, explains Dr Amparo Lopez-Rubio from the Institute of Agrochemistry and Food Technology (IATA-CSIC) in Valencia, Spain, and coordinator of the BIOCARB-4-FOOD project
„The algae industry already generates global sales of around 7.4 billion dollars (around 6.3 billion euros) - and the trend is rising. Because of their special physico-chemical and biological properties, the food and pharmaceutical industries are also showing growing interest in compounds made from algae.“ Dr Nadja Reinhardt from the Research Centre for Bioeconomy at the University of Hohenheim.
One of the BIOCARB-4-FOOD subprojects aims to obtain novel extracts that can be used as food ingredients - far beyond their use as gelling or thickening agents. This is because the scientists also see potential due to the specific properties of these algae carbohydrates, also known as phycocolloids, use them as smart packaging materials.
Plastics derived from algae
The researchers at BIOCARB-4-FOOD are therefore working on more sustainable food packaging that has the necessary mechanical and chemical properties.
„We need to look for alternative sources of raw materials that do not compete with food production. This is the reason why marine resources such as algae and seagrass are very interesting. They reproduce very quickly, grow in a variety of environments and, as an alternative biomass source for bioplastics, do not interfere with food production.“ Dr Amparo Lopez-Rubio
Even the remains of industrial extractions can be utilised. This is because the remaining biomass still contains enough bioactive compounds to produce new types of carbohydrate-based extracts and fibres. For example, cellulose and nanocellulose, which can be used for the development of biodegradable packaging materials, which has been successfully tested in the IATA-CSIC laboratory.
New extraction processes lead to more sustainable packaging
Industrially, highly purified agar extracts are usually used, which is associated with a high consumption of chemicals. Less purified agar extracts, on the other hand, have additional functions, such as antioxidant and antimicrobial properties, which make them interesting for various food applications: Knutrient films made from these extracts release bioactive substances and can therefore contribute to food preservation, for example, by slowing down the spoilage of fruit.
In addition, these films can overcome one of the main obstacles to the use of agar in the food packaging industry: they are much more resistant to moisture than films made from highly purified agar.
Bioplastics from unwanted seaweed waste
A good utilisation option is also characterised by for the waste of the Neptune gas native to the Mediterranean (Posidonia oceanica) from. This plant sometimes accumulates in large numbers on the beaches, which has a negative impact on tourism and leads to high removal costs for the affected communities.
However, the ingredients of this Posidonia waste have a large Potential for the development of biodegradable packaging, which is also underpinned by a separate patent: They are an excellent source of so-called lignocellulose. As an additive, it leads to a significant improvement in mechanical properties in the production of starch-based bioplastics.
The Posidonia cellulose can also be added to conventional plastics, to improve various important functions of food packaging, such as the gas and water vapour barrier and thermal or mechanical properties. Together with a variety of bioactive substances in Posidonia extracts, which have a high antioxidant capacity, these properties also contribute to to keep food fresh for longer.
Source: University of Hohenheim
