University of Queensland studies have explored the use of natural tree sap gum and light to extend the shelf life of fresh fruit and vegetables, aiming to combat food waste.
Research conducted by the Queensland Alliance for Agriculture and Food Innovation (QAAFI) involved edible coatings made from gum Arabic, also known as acacia gum, enriched with extracts from native Australian plants. These coatings were found to effectively stop the growth of spoilage-causing microorganisms. In addition to the edible coatings, the research team also used light and curcumin, a compound extracted from turmeric, to deactivate fungal spores on food.
Dr. Maral Seididamyeh from QAAFI explained that both methods were effective in keeping food fresh for longer. She noted that using the edible coating prevented the growth of spoilage microorganisms in freshly cut capsicum for approximately ten days when stored in the fridge. This preservation effect was attributed to the organic acids and phenolic compounds found in aqueous extracts of plants such as Cape York lilly pilly, boonjee tamarind, and Tasmanian pepper leaves. These extracts demonstrated promising antimicrobial properties, and sensory analysis revealed that the fruit looked and smelled better as a result.
The curcumin-based photosensitization technique was found to be highly effective, completely deactivating the fungal spores responsible for grey mold in fresh produce. When applied to strawberries, this method reduced decay incidence and severity by 20 per cent without compromising the fruit's color or firmness.
Dr. Seididamyeh emphasized the growing demand for chemical-free methods to prevent food spoilage. She pointed out that bacteria, viruses, fungi, and parasites are increasingly becoming resistant to synthetic chemicals commonly used for food preservation. As a result, consumers are showing a stronger preference for natural preservatives over synthetic additives.
According to data from the Food and Agriculture Organization of the United Nations, 17 per cent of food is lost to spoilage and other issues at retail outlets and in homes. While the research findings are promising, Dr. Seididamyeh noted that further work is required, particularly as photosensitization is still a relatively new concept in the food industry.
She explained that photosensitization is already being used in medicine, particularly in photodynamic therapy to destroy abnormal cells in cancer and precancerous treatments. However, the edible gum coating, which is embedded with extracts from native Australian foods and leaves, as well as curcumin, remains costly. To make this a viable mainstream solution, further funding will be necessary to refine the technology and integrate it into commercial packaging and processing lines.
For more information:
Natalie MacGregor
University of Queensland
Tel: +61 409 135 651
Email: n.macgregor@uq.edu.au
www.uq.edu.au