Waste transformation is not a new concept but it is time to reframe how we see it. Food scientist Dr Anneline Padayachee explains why.
Humans have been transforming food waste into different products for thousands of years. The process is as old as the household compost bin; simplistic and requiring little thought or technology.
We turn foods we cannot, or do not, want to eat into something with a better purpose (i.e. compost) than binning it as no-value rubbish.
It is a similar story for the food industry. For example, the rendering of raw animal fat into a shelf-stable product used to create everyday essentials including soap and candles, lard and tallow is one of the oldest industries dating back to6000BC with the Ancient Mesopotamians.
In fact, given the diversity of the food supply and the need to effectively treat waste by-products, over the centuries the render sector has grown to encapsulate all forms of waste treatment and upcycling.
Peter Milzewski, president of the Australian Rendering Association, says, “This critical industry generates more than $50 billion in revenue each year for the Australian economy.”
The National Food Waste Strategy identifies ingredients reprocessing for the cosmetic, nutraceutical, pharmaceutical, and industries as a viable strategy to decrease food waste.
This mirrors the UN’s Food and Agricultural Organisation (FAO) position that resource optimisation as a method of waste reduction will contribute greatly to society.
Time for a rethink
Given our greater understanding of food components and the need for a more sustainable food supply, it may be pertinent to rethink food waste as a source of high value components instead.
Although we think of what we eat as food as opposed to as a source of nutrients, that is exactly what food is, a collection of different nutrients and bioactive components in edible form.
Consider the dietary fibre in fruits and vegetables, which is composed of cellulose, pectins, hemi-cellulose, and lignin, the percentages of each varying between produce.
Because citrus and apples peels have high pectin content, reprocessing them, both by-products from juicing, provides pectin for other uses.
As our understanding of food components and bodily functions increases, more novel commercial opportunities with applications beyond just the food industry that improve health while simultaneously decreasing food waste are becoming available.
Currently, there are at least 24 patents pending for using food by-product extracts in health foods, cosmetics, functional ingredients, food packaging, and medical uses.
The research sector has a long-standing interest in this arena, identifying nutritive or functional components in foods and by-products.
Chemically derived lipase-inhibiting medication is used to treat complex obesity by decreasing fat absorption in the small intestine.
However, pectin extracted from apple juice pomace has been found to also inhibit lipase activity in the pancreas.
Banana peel transformation is another example of resource optimisation for use as a functional ingredient in high value applications. Banana peels are an exceptional source of dietary fibre, but are also a potent source of polyphenol compounds shown to have antimicrobial, antibiotic and antioxidant properties.
Applications for banana peel extracts range from preserving soybean oil and chicken mince (antioxidant), prawns (antimicrobial), providing active ingredients in pharmaceutical products including Parkinson’s disease and diabetic medications, and stimulating growth of gut mucosa cells in the colon.
As the world produced nearly 120 million tonnes of bananas in 2020, and 35 per cent of the fruit is the peel, there are a lot of banana peel transformation opportunities to commercialise.
Even wheat germ, a by-product of wheat processing, is a relatively plentiful source of the protein agglutinin.
It has been found to improve targeted delivery medications for cancer treatments and antifungal therapies.
Lucrative offers
As upcycling food waste by-products becomes more mainstream, it also becomes more lucrative, sometimes in innovative ways.
In 2018, Kellogg’s UK partnered with Seven Bro7hers Brewery to convert rejected Cocoa Pops, Rice Bubbles, and Corn Flakes into beer.
Overcooked, uncoated, and discoloured cereals were repurposed and upcycled to replace some of the malted barley in the brewing process, creating a niche, high-valued craft beer.
University of Leeds researchers created a hair dye made from anthocyanins extracted from Ribena blackcurrant cordial pomace to reduce the risk of allergic reactions common to synthetic dyes. It presented a lucrative opportunity considering the global hair dye industry is worth more than $29 billion.
With no industry partnership, the academics developed their concept hair dye into the retail brand Dr Craft, and are now branching into cosmetics and skin care based on nutraceuticals extracted from mandarin peels.
There is a major flaw in the way we have traditionally classified waste; as having no or low value because it is deemed to be inedible.
It may be better to look at waste as by-products with identifiable high value components that have a range of applications.
The research is there and growing, and all that is needed are commercial partners and science translators to bring it to reality.
One thing that’s for sure is that food is a great source of nutritive components that go beyond a full belly and dietary health. Food is one of our most prized resources in more ways than we give it credit.
This article first appeared in the June edition of Food & Drink Business magazine.
