Food waste is a major global issue, with approximately 1.3 billion tonnes of food wasted each year. In Australia alone, around 7.6 million tonnes of food is wasted annually, costing the economy approximately A$36.6 billion. However, a recent study published in Bioresource Technology Reports has discovered a way to utilize food waste to create nanocellulose, a versatile material. The researchers specifically used acid whey, a waste product from dairy production that is typically difficult to dispose of.
Nanocellulose is a biopolymer made up of long chains of sugars. It has unique properties, such as strength, chemical stability, and biocompatibility, making it suitable for various applications like packaging, wound treatments, drug delivery, and food production. The traditional method of producing nanocellulose is expensive, energy-intensive, and time-consuming, often resulting in unwanted waste byproducts.
In contrast, the new approach developed by the researchers uses only food waste and a symbiotic culture of bacteria and yeasts known as SCOBY (used as a kombucha starter). The process is cost-effective, consumes minimal energy, and produces no waste.
The researchers used acid whey, a liquid waste product from a local cheese manufacturer in Melbourne, Australia. Acid whey is rich in carbohydrates and proteins but is challenging to process due to its high lactic acid content. The researchers heat-treated the liquid, added sugar and yeast extract, and introduced SCOBY. Over four days of fermentation, the bacteria produced nanocellulose material that floated to the top, forming a pellicle similar to the one found in homemade kombucha.
The demand for nanocellulose is growing globally, with the market expected to reach US$2 billion by 2030. Nanocellulose can replace petroleum-based and non-renewable materials in packaging and other applications. It is fully biodegradable and can be customized by infusing it with compounds like glycerol to enhance flexibility. The researchers are also exploring the use of nanocellulose as “smart” packaging by incorporating indicators that signal food spoilage.
The study demonstrates an efficient circular economy approach by upcycling dairy industry waste into sustainable nanocellulose. The sediment residue produced during the process has commercial value as a fertiliser or animal feed, and the liquid culture can be reused for future batches. Scaling up this approach for commercial use and exploring alternative food waste sources are future challenges.
Overall, the study shows the potential for producing nanocellulose in a sustainable manner, transforming food waste into valuable materials.