Safely achieving clean label products through thermal, non-thermal and emerging processing techniques

18 June 2024 | Craig Leadley, Technology Fellow

As for any type of reformulation exercise, ‘clean label’ innovations require developers to strike the right balance between cost, availability of ingredients, nutritional profile, taste, packaging, product shelf-life and regulatory considerations.

The choice of processing also needs to be factored into this balance.

When producing clean label products (just as when addressing many other of the challenges or opportunities in the food and drink industry), there can be trade-offs and tensions between different solutions.

For example, developing a clean label product may come with the food safety considerations of removing preservatives. Or a developer may be aiming to produce a more sustainable product, but removing preservatives could result in more waste.

This blog covers how different processing technologies can be used to achieve safe, clean label formulations with the desired shelf-life. And, in some cases, other benefits too.

Clean label by process

Thermal processing

In achieving the safe production of these products, traditional thermal preservation technologies will continue to play a foundational role.

Just because these technologies are well established, it does not mean they should be overlooked – they are very powerful tools that manufacturers can use to achieve the required shelf-life whilst minimising the use of preservatives.

Thermal processing technologies include traditional heating examples such as pasteurisation, UHT and retorting as well as electrified rapid heating techniques such as microwave heating, ohmic heating and induction heating. Freezing is another traditional thermal processing technique and is an effective way to achieve a long shelf-life without the need for preservatives.

Electrified heating

Electrification of thermal processing, preservation technologies looks set to facilitate clean label whilst improving sustainability.

Induction heating is an electrified heating technology. It is also a great example of where both the sustainability driver AND the need for clean label work together.

It uses a wound metal coil (similar to the induction hobs used domestically), which is electrically powered, and a heated metal element, which then heats the product. Industrial processing with induction heating involves the powered coil being wrapped around a pipe with the flowing liquid inside. The induction coil heats the heating applicator (the element inside the pipe), which heats the liquid in the pipe. The heating applicator also acts as a mixing device to ensure consistent heating, and provides a large surface area in a compact space to improve the heat transfer.

The improved heating efficiency can reduce start up times and shorten the length of the heating zone, which can reduce waste during operations on start up or recovery from stoppages. With claims of up to 90-95% of the energy directly transmitted to the liquid being heated by induction heating, this technology could improve efficiency as well as reduce greenhouse gas emissions. Plus, the fast electrical responses allow tighter temperature tolerances to be maintained – which could lower manufacturers’ target temperatures, because these are typically set higher with steam-based systems which can be slower to respond.

Applications include trim heating, kettle boosting, as well as the heating of any liquid product for hot fill, UHT, or pasteurisation, such as beverages, purees, sauces, stocks, bases and oils.

Non-thermal processing

Like electrified heating, non-thermal technology uptake is also likely to continue to grow (particularly in high-value, niche products).

Both high pressure processing (HPP) and pulsed electric field (PEF) technology offer non-thermal processing solutions to help achieve clean label products.

HPP is now a well established process for pasteurisation, can inactivate vegetative microorganisms, and is sometimes used to bring about desirable changes to food. For many products (e.g. ready-to-eat vegetable meals, guacamole, dry-cured products preservative-free) HPP enables pathogen control and shelf-life extension (up to 3 times or greater compared to unprocessed products), both without preservatives and with minimal impact on sensory properties (can protect the degradation of natural ingredients that are thermally sensitive). Furthermore, as it is an in-pack process, it reduces the risk of product recontamination after processing.

PEF technology applies high electric voltage pulses to products to cause electroporation in cells. Lower electric field strengths can be used for inducing holes in larger cells like vegetable or meat cells (e.g. for extraction or improved drying). Higher electric field strengths are required for perforating small cells like microorganisms (for using PEF to decontaminate and pasteurise products). PEF provides a gentle means of pasteurisation compared to using thermal processing, but temperature can also be used to enhance the microbial inactivation achieved through PEF.

This gentler treatment can offer advantages such as improved colour retention. Thermally sensitive components like natural green colours (which would be discoloured by thermal methods) can be better protected with non-thermal technologies like PEF. For example, PEF application for a fruit smoothie with natural clean label colour from spirulina shows a better protection of the thermally sensitive blue/green colour, and various PEF-treated juice products are available in the cold shelves of several supermarkets.

Emerging techniques

Emerging techniques, such as gene editing, precision fermentation and cellular agriculture, may also be able to facilitate clean label, minimally processed and more sustainable products.

Examples include producing non-animal dairy products (such as animal-free whey), nature identical colours and flavours, sustainable/ethical ingredients (e.g. palm oil produced from yeast fermentation) and gene edited crops (to boost nutrition, reduce allergens, and delay spoilage).

How we can help

Our knowledge and expertise place us at the forefront of global scientific innovation in this sector. No matter what our client challenge may be, we consistently deliver innovative solutions, helping clients to conquer their market with safe, successful products.

We can help you to develop clean label formulations that meet market need by ensuring that you have the understanding, ingredients, processing and packaging to support a safe product that meets regulatory requirements and has the desired shelf-life.

We can also help clients to explore new processing techniques and validate these for their products.

About Craig Leadley

From more than 30 years in the food and drink industry, the majority of which spent supporting clients and conducting research here at Campden BRI, Craig has a vast range of knowledge and experience, as well as extensive industrial and academic connectivity.

Over his career he has built our multi-partner collaborations, developed grant applications, overseen our research programme, and been involved in food preservation and manufacturing (with a particular focus on thermal processing and emerging technologies, about which he has published a number of books and journals).

Craig supports companies with accessing grants, and is currently focused on start-up and small to medium-sized enterprises (SMEs) through grant funding.

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