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Cutting down on food waste

Lucas Westphal and Dan Hall at Campden BRI in the UK look at how we can reduce food waste while maintaining food safety.

The Food and Agriculture Organisation (FAO) of the United Nations estimates that if food waste was a country, it would be the third-highest emitter of greenhouse gases after the US and China. Alarmed? With tonnes of food wasted in the UK and Ireland each year, you’re right to be.

Food manufacturers tolerate roughly 5% waste within their food processes under normal production, but often look for ways to reduce it. Monetary factors, such as the potential cost reduction and increased profits as a result of waste prevention or valorisation, can be an important driver behind reducing food waste.

While local waste legislation can play a part, many other ‘indirect’ monetary factors can play a role like the ethical responsibility of an organisation to reduce greenhouse gas emissions and improve local food security. Other potential benefits include the improvement of the brand image and reputation of an organisation, but also the opportunity for strengthening stakeholder relationships. On top of this, food manufacturers may well face taxation in the future so planning ahead would mitigate this.

Reducing food waste – a closer look at waste streams

Assessing your waste streams can help reduce food waste and there are two main approaches:

Identifying waste streams and assessing preventable waste - Here, it’s important to consider how discrete the waste streams are: Is everything combined together? Or can a fraction be held back before this combination happens? If a waste fraction can be isolated, consider analysing it for its nutritional/functional value so the most can be made from it. For preventable waste, consider working with everyone – from factory operatives and technical to food safety – to ensure there is a full picture of how the waste is created and managed.

For example, in a scenario where the final products are considered faulty and not fit for sale: Could the process be optimised to have fewer products like this? If not, can the products be used in an alternative way? Is it a shelf-life issue or a cosmetic one? There may be an alternative sales stream that will accept these items (food banks if non-perishable etc.)

Repurposing of “non-preventable” by-products - For those by-products that are inevitably going to be wasted, some food businesses try repurposing them. We have experience of this at Campden BRI following our research that incorporated butternut squash skins into tortillas doubling their fibre. Consumers like familiarity, so producing a high fibre product that is similar to a well-known one is a great way of helping ensure sales while increasing the public’s fibre intake. The additional advantage here was that the butternut squash skins provided a golden colour to the tortillas which added to their appeal.

Another example of repurposing what would otherwise have become food waste is our work on seafood shells. Our experts processed shells that had been removed from seafood into an aquatic feed. This shows that food waste doesn’t necessarily have to be repurposed for human consumption.

An important part of repurposing waste is the benefit-cost analysis, i.e. if we invest into repurposing this waste stream, how much will we get in return out of it? The Business Case for Reducing Food Loss And Waste is a publication by WRAP (Waste & Resources Action Programme is a British registered charity) that can provide some insight into this.

When individual food businesses consider repurposing food waste, it’s helpful to think of what the benefit is for the industry as a whole, beyond how their business could benefit alone. For example, repurposing food that would have otherwise been wasted will help the industry combat the 1.5 million tonnes, equivalent to £1.1 billion, of food wasted during the manufacturing process, as was found in 2018 by the Waste & Resources Action Programme (WRAP).

What materials/waste streams should manufacturers look at to maximise food waste reduction?

Here, we suggest taking a holistic approach and looking at everything from raw materials to the final product at the consumer stage. Special attention should be given to bulk by-products as sometimes the best opportunities can be found here; even a small tweak in production could have a massive impact on bulk by-products. What this product is of course depends on the type of company we are looking at helping. A few examples of bulk by-products include: shells of crustaceans which are not consumed, peels/seeds of fruits and vegetables (generally anything which is the outer shell of something valuable inside)  and aqua faba.

A good example comes from breads often discarded by consumers at home. To give some background: Bread is one of Britain’s most wasted foods. According to figures from the UK Office for National Statistics, around 24 million slices of bread are thrown out by UK households every day – making up more than a third by weight of bakery food waste. But this isn’t an issue exclusive to the UK, we see the same story play out across Europe; 10% of bread and baked goods end up as waste after going stale or not being sold on the day of production.

With this in mind, increasing the shelf-life of bread can reduce waste at both the retail and consumer stage. How? Firstly, consumers associate the best before date of breads with its freshness (at least for packed breads), so a bread with a longer best before date will be considered fresher compared to one with a shorter one. Secondly, breads will last longer and can be consumed before reaching their best before date (some consumers don’t know the difference between best before/use by and discard everything past its due date).

Another example comes from cacao pulp. The cacao pod is comprised of a husk, pulp and beans. The beans are typically removed from the husk and kept in the pulp to ferment and develop flavour. The resulting fermented pulp is usually put back into the soil. Cacao pulp once fermented is full of vitamins and minerals, and a natural sugar replacer. It’s not surprising then that there are some ‘whole fruit’ chocolate products out there that use cacao fruit as a replacement for sugar. Considerations should be made for how the fermented by-product can be captured whilst keeping microbiological contamination in mind.

Are there any safety considerations?

A lot of by-products or waste streams have a high water content and usually high water activity is ideal for microbiological growth. Pair this with the nutrients available and the clock starts ticking for preservation to take place. An example of this is brewer’s spent grain which is high in protein and fibre, but as it is part of a live fermentation, the need to cool it down quickly is essential.

Extracting materials for repurposing

There are different approaches for extracting materials that are to be used to repurpose food waste. The first is using by-products without sophisticated further processing. The outcome here is a material that is very cheap but also very variable in its composition and performance, the latter not being as helpful when attempting to repurpose it. Alternatively, extraction of high value components (fibres, proteins, micronutrients) preferably by physical means of separation (for example, size or molecular weight) can provide ingredients with superior functionality. It’s important to note here that physical extraction (instead of chemical/biochemical extraction) will mean a greater chance of declaring the ingredient as more clean label, i.e. without using ‘modified’ etc.

What to consider when marketing products made from by-products

Ultimately, the product you’ve developed by repurposing food waste will be marketed, usually to consumers. When doing this, important considerations include whether there are any pesticides on the repurposed by-product, whether it could be considered a novel food and which form the product will be supplied in and how this affects its functionality (for example, dried product can have altered properties to the hydrated form depending on the drying method).

Digitalisation as a solution

Our team at Campden BRI Hungary is currently working on an EIT Food funded project to optimise bakery processes and predict actual consumer demand with computational tools. This will ultimately reduce food waste. The project, known as PrO4Bake, will help small and medium-sized bakeries remain competitive by saving on costs associated with the production of baked goods.

How will the Industry 4.0 project achieve this?

Industry 4.0 refers to the transformation of industry through the intelligent networking of machines and processes with the help of information and communication technology (ICT). The term is used interchangeably with the ‘fourth industrial revolution’ in industry. The computational tools will allow manufacturers to adjust the amount and range of baked products to the demands of consumers, while adapting production planning and processes to best practice. This will make machine-powered processes more efficient which, in turn, will reduce raw material use, energy consumption and CO² emissions. We can expect these outcomes to lower manufacturer’s production costs all while offsetting some of their carbon footprint.

Food waste in a nutshell

To summarise, there are a number of ways that food and drink manufacturers can potentially reduce food waste but before doing so there are a few considerations to bear in mind. Sometimes, the best way of reducing food waste is to look at examples of how other companies have successfully achieved it and to emulate their process. Alternatively, our experts at Campden BRI have helped a number of food businesses from across the industry reach their food waste targets by building on the experience from each case.

About Lucas Westphal

Lucas works as a Senior Bakery Scientist within the Baking and Cereal Processing Department at Campden BRI. He holds a BSc in home economics and nutritional sciences from the University of applied sciences Niederrhein in Germany and graduated with a first class in Food Science (MSc) from the University of Reading.

About Dan Hall

Dan has been with Campden BRI since 2011 and works in the Product Innovation team in the Food Manufacturing Technologies department. He has a degree in Chemistry and has written publications as part of Campden BRI’s member funded research programme.

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