Rice and coffee husks for food preservation

Starch films are biodegradable materials that have attracted enormous interest for use as sustainable alternatives to conventional plastics in food packaging in recent years. However, despite their vast potential, they also have some limitations that hinder their commercial application.

To address them, a team of researchers from the Universitat Politècnica de València (UPV), belonging to the Institute of Food Engineering for Development (IUAD) and led by Dr Amparo Chiralt, is working on improving the properties of these films, incorporating products such as active extracts and cellulose fibres isolated from rice or coffee husks.

These extracts stand out for their high phenolic content and excellent antioxidant and antibacterial capacity. Thus, in their studies, the researchers of the IUIAD of the Universitat Politècnica de València found that their incorporation highly improves the mechanical strength and the barrier capacity to water vapour and oxygen of thermoplastic starch films and provides them with antioxidant and antibacterial properties. In addition, the incorporation of cellulose fibres further improves the mechanical strength of these films.

This makes these active extracts and cellulose fibres from rice and coffee husks suitable candidates for improving the properties of starch films as an alternative to traditional packaging plastics.  Their use in food packaging has the additional advantage of their potential antimicrobial and antioxidant capacity, which would result in better preservation of the packaged food and less impact on the environment.

Starch films would have specific applications in fatty food packaging without free water, where antioxidant action could prevent oxidative spoilage. For food applications with free water and the risk of microbial spoilage, combining them in laminates with other hydrophobic biodegradable materials, such as PLA, would be necessary to prevent starch wetting. Further studies by the research group in this regard have demonstrated the ability of these laminates to extend the shelf life of fresh pork. 

However, according to the UPV IUIAD researchers, it would also be necessary to reduce the cost of the materials and increase their availability to bring these developments to the market. This is the only way to meet the needs of the food sector.

Reference

Sofía Collazo-Bigliardi, Rodrigo Ortega-Toro, Amparo Chiralt, Improving properties of thermoplastic starch films by incorporating active extracts and cellulose fibres isolated from rice or coffee husk, Food Packaging and Shelf Life, Volume 22, 2019, 100383, ISSN 2214-2894, https://doi.org/10.1016/j.fpsl.2019.100383