Innovation

Innovative process squeezes more value out of apples

With the help of bacteria, apple pulp from juice production can be fermented and utilized to make new beverages, natural flavouring agents, and even artificial leather, if a new DTU start-up has its way.

Hands that scoop up handfuls of apple pulp — The production of 10 liters of juice generates up to four kilos of pulp. By further processing the pulp, it is possible to squeeze more value out of it. Photo: Beyond Leather Materials

Wednesday 25 January 2023

Miriam Meister

If we are to succeed in feeding the world’s growing population, we also need to find innovative ways to get more out of the raw materials available to us, in accordance with UN Sustainable Development Goal 12 on responsible consumption and production.

An obvious idea is to reuse the huge volumes of the residual product pulp that is created in the production of apple juice. This is the opinion of three DTU researchers, who, together with a fourth partner, are behind the start-up Bioflavours, which will make new beverages and ingredients by fermenting the pulp.

“We need to radically change our food system to make it a more circular system, where side streams become new healthy ingredients or foods instead of ending up as biogas,” says co-founder Claus Heiner Bang-Bertelsen, who is also a senior researcher at DTU Food. Fermentation is the focal point of most of his research.

Fermentation is a process in which an ingredient—such as apple pulp, i.e. the residual product that remains when juice is squeezed out of apples—is placed in tanks together with carefully selected bacteria. Under closely monitored temperature conditions, the bacteria break down the sugar in the ingredient over a few days, thereby inducing fermentation.

When the apple pulp ferments, the bacteria form flavouring agents and aromas. The four researchers behind Bioflavours can then squeeze an aromatic liquid out of the fermented pulp. They can use this liquid as the main ingredient in a slightly fizzy soft drink. Or they can process it into a sweet syrup that can add flavour and aroma to other foods and beverages.

“Our concept is a good example of how—by thinking outside the box—we can create more value and extract more ingredients from the world’s raw materials. In our small way, we can consequently help combat the big problem with waste,” says co-founder Timothy Hobley, who—in addition to being a fermentation expert and responsible for DTU Brewery—is also Associate Professor at DTU Food.

Drink made with pulp from the production of juice. — Bioflavours produces an apple-flavoured soft drink that resembles both juice and cider yet does not taste like either. Photo: DTU

Utilized for artificial leather

And, in fact, the utilization of the residual product does not stop there. Bioflavours works with another start-up, Beyond Leather, which produces artificial leather. Apple pulp is very suitable for precisely this purpose—and the fermentation process makes the pulp even better for Beyond Leather to work with, as it eliminates the almost 10 per cent sugar found in pulp when the juice is squeezed out. In this way, you are left with a mass that basically consists only of fibres, which ensures a better end product—and it potentially also means that no parts of the apples that were initially squeezed into juice go to waste.

“It is actually easier to use apple waste, which has a lot of value and potential to offer if we dare to think big. It took a lot of trials and errors to create our plant-based leather alternative Leap, and DTU is definitely a valuable partner along this journey,” says Beyond Leather’s R&D project manager Xianrong Shao.

Plant- based leather made from apple pulp — The plant-based leather is available in different colours and comes in two different surface finishes. Photo: Beyond Leather Materials

Taste is the make-or-break ingredient

For manufacturers developing new foods and beverages, one of the biggest challenges is hitting a taste profile that is spot on.

“It may well be that a company has developed a nutritious product, but if consumers do not like how it tastes, it will not succeed in the market. 90 per cent of the products that fail after they have been introduced in the market fail because of taste and texture,” says Leif Nielsen, Director of the Danish Food and Drink Federation (DI Fødevarer).

This is a reality that the people behind Bioflavours are highly aware of, and they have also worked intensively to find the right taste profile for their product, including with two grants from DTU earmarked for the maturation of business ideas.

They describe the product they make with the fermented liquid as an apple-flavoured soft drink that resembles both juice and cider yet does not taste like either.

The start-up has also successfully experimented with adding mint or ginger and a small amount of sugar to sweeten the product a little. In this way, they can expand the range as needed.

The soft drink has been served as samples at events at DTU with a wide audience. Here, Bioflavours has taken a scientific approach and collected users’ reactions to the product with the help of SensiMate—another DTU startup that has developed an online platform for conducting user surveys. Bioflavours uses this valuable information in its ongoing work to achieve the best taste experience for the widest circle of consumers.

Profitability is key

It is one thing to make a product that consumers want to buy. But the business model stands or falls with the product’s ability to be manufactured at a price that consumers are willing to pay and that the start-up can make money from. Several factors strengthen the profitability of the concept:

Bioflavours can buy pulp in large quantities for very little money. The bacteria that will kick-start the fermentation process are already present in DTU Food’s collection of bacterial strains, which means that it is not necessary to purchase starter cultures. And the excess dry pulp becomes a source of income when it is sold to ‘leather’ manufacturers.

The team behind the start-up expects to be able to launch the product this summer.

FACTS

Apple pulp as resource

Danes drink an average of about nine litres of apple juice a year, according to figures from DTU Food.
Production of ten litres of juice generates up to four kg of pulp.
Adding approximately ten times as much water to four kg of pulp, Bioflavours can produce 40 litres of fermented liquid which can be turned into a soft drink.
Danes drink on average more than 1 litre of soft drink (soda water sweetened with sugar and sweeteners) per week, according to DTU Food’s figures.
Disposal of the pulp to biogas plants represents an expense for juice producers. In rare cases, they can earn a little by selling it for animal feed production.

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