A huge, untapped resource. Apple is the fourth most consumed fruit in the world and according to the United Nations’ Food and Agriculture Organization, we produced more than 86 million tonnes of apple globally in 2018. The biggest apple producers are China, the US, Turkey, and Poland. Together they account for nearly half of the global production.
Around 75% of apples are being consumed freshly, while 25% is turned into other products, like jam, wine, or apple juice which is still the most sought-after product made of processed apples.
Apple waste, also known as apple pulp or pomace is everything leftover of the apple after pressing it for juice or cider production. In other words, it is the core, the stem, and the skin of the apple. Approximately 25% of the fruit goes to waste during pressing. It is estimated that a shocking 3 000 000 tonnes of apple waste are being generated every year. Can you even imagine that mountain of apple pulp?
The huge amount of waste actually poses a public health hazard. Only a surprisingly low percentage of the waste is being utilized, the rest goes to landfills where it pollutes the environment. One would think that it’s just apple, what harm could it cause? Isn’t it just going to biodegrade? Yes, it will, and due to the high biological and chemical oxidation demand, it will help microbes increase the risk of diseases and decrease available nitrogen in the soil. Moreover, the high water content will start an unpredictable fermentation process while the rotting releases methane, a potent greenhouse gas.
Unfortunately, waste management is expensive for farmers. The pomace needs to be transferred to the landfill or be combusted. And if we actually want to use it as fertilizer or feedstock, it needs to be properly stored and processed, which comes with even further costs.
Despite the fact that a very small fraction of apple pomace is utilized, there are some ways to give it a useful afterlife.
Composting is the most obvious choice to put apple waste to use. Instead of letting it rot in a landfill, we can use certain microbiomes or earthworms to rot the pomace under regulated circumstances. This way, it becomes a smaller risk to the environment and the people, and it can be used again to provide nitrogen to the soil and improve soil fertility and crop productivity.
Similarly, the pulp can be used for biofertilizers that contain beneficial microbiomes to help soil activity and fertility. Biofertilizers are better for the environment than chemical fertilizers and are more affordable for farmers.
The downside of this is that we don’t use the full potential of apple waste, and although composting is a better solution than leaving it untreated, it doesn’t add that much value to it.
The leftover fruit waste can also be used as animal feedstock, however, it is not easy for the animals to digest, it has a low nutritional level, and the high sugar content leads to further fermentation, which…well…makes the animals drunk.
Another common way to re-use the leftover apples is by turning them into biofuel. As renewable energy sources take over the place of fossil fuels, bioenergy is one of the most promising and inexhaustible alternatives. Several types of biofuel can be produced from apple waste: biogas, biodiesel, biohydrogen, bioethanol, and biobutanol.
"It is estimated that a shocking 3 000 000 tonnes of apple waste are being generated every year."
The pomace can also be used to extract several useful components from it: organic acids, enzymes, aroma compounds, antioxidants, polyphenols, and biopolymers. Did we lose you at enzymes? Let us break it down.
Organic acids can be used in the cosmetics, detergent, food, pharmaceutical, and textile sectors. The global organic acid market is a fast-expanding one, and apple pomace is suitable for the production of several types of acid with less environmental pollution than chemical acid production.
Similarly to organic acids, enzymes are used in a wide range of industries from food and beverage to textile and pharmaceuticals. The global market size of industrial enzymes is approximately $6.3 billion today, and extracting enzymes from apple pulp via microbes can be a cost-effective method to produce these otherwise relatively expensive substances.
Aromas take up 25% of the global demand for food additives. They can also be synthesized in chemical and biological ways, but biological methods (for example extracting them from apple pulp) are more favored due to health benefits.
Antioxidants and polyphenols are used for food, pharmaceutical, and cosmetic applications to a great extent because they are known for their antimicrobial, anti-inflammatory, anticarcinogenic, and cardiovascular protective properties.
Biopolymers are technically bioplastics. The most commonly used biopolymer is PHA (polyhydroxyalkanoates) which is biodegradable and biocompatible and it is used not just for replacing traditional plastic packaging but is also widely used in the medical field. It can provide an environment for the growth of tissues and organs and can be used for drug delivery.
Food and beverages
Thanks to its high content of dietary fibers, apple pulp can also be used in food products and beverages as an additive. From adding apple pulp to bread, cakes, and crackers, scientists also experimented with adding apple pomace to meat products to increase their dietary fiber contents. They also successfully used apple waste as a stabilizer and texturizer in yogurt. Would you have thought that leftover apples are so versatile?
Of course, for us, the most obvious use of apple waste is to turn it into a high-value leather alternative. Well, maybe it wasn’t that obvious in the beginning. It took a lot of experimenting, trials, and errors to come up with an end product that can be a sustainable alternative to leather. It took even more research and development to create Leap as you know it today. Our goal was to show the world that a seemingly worthless resource can be turned into a high-value product, and by doing so, we can change one of the most polluting industries into a sustainable one.
By now we know that in the fashion industry, up to 80% of the environmental footprint comes from raw materials. We should start looking at and treasuring what we have at hand - like waste.
Apple waste deserves to be treated as an equal to virgin materials or even superior to them, even in industries where you didn’t expect to see waste. Virgin fabrics don’t equal high quality or high fashion anymore, in fact, they are often unnecessary. Whereas being upcycled actually adds value to a material.
We believe that upcycling is the only way forward.