Meet the Expert
Who: Kathy Groves
What: Head of Microscopy
Where: Leatherhead Food Research
With many manufacturers struggling to meet the government’s 2017 salt reduction targets, Public Health England (PHE) is set to launch a consultation with companies to understand the issues standing in the way of success. As with sugar reduction, salt contributes much more than taste to a product, so it’s not as easy as just taking it out. Salt enhances flavours and can suppress bitterness, it helps meat stay succulent and tender, delivers crunchiness to snacks, gives springiness to bread and preserves food, keeping it safe throughout its shelf life.
So, as a product developer, how do you go about reducing salt in foods? The first step is to establish salt’s primary function – if it’s in the product to enhance flavour or preserve it, then reducing salt will be easier. However, if it’s there for a textural reason, you’ll need to take a deeper look and characterise the effects of either reducing or removing the salt.
Leatherhead Food Research delivers this understanding through a scientific approach we call ‘blueprinting.’ Blueprinting involves assessing the sensory properties of the reduced salt product and comparing it with the standard high-sodium one, then measuring and understanding the sensory profiles through a number of scientific methods. These methods usually involve measuring the product’s microstructure, determining how the ingredients are distributed and how lowering salt has affected dispersion, as well as taking instrumental measurements of the textural changes.
Once you understand the effects of salt reduction on a product’s properties, there are five key ways to lower salt in foods:
Five ways to successfully reduce salt in foods
- Alternative preservation methods. If the main function of salt is to preserve the product, alternative preservatives or methods of processing can be explored depending on the food type. Alternative methods or ingredients include reducing the water activity (for example, by drying), lowering the pH or adding sugar. Sorbate, benzoate and nisin could be used as alternative preservatives, but this would mean that the product would not be considered clean label; clean label alternatives include rosemary, garlic and oregano.
- Stealth reduction. If salt is being used mainly for taste, one approach being successfully used by manufacturers is slowly reducing salt so that consumers’ palates become adjusted to a lower salt intensity. This is sometimes referred to as ‘stealth’ reduction. This needs to be carried out in small increments so as to avoid adverse consumer reaction. At some point the effects on functionality may become more dominant – even small reductions in salt can have an impact on a product’s shelf life, taste and texture.
- Use a salt replacer. Substituting part of the sodium chloride with a non-sodium salt such as potassium chloride is an option. Whilst this may lower sodium content, differences in the taste of the replacers is often an issue, so careful balancing is required.
- Restructure the salt. Reducing the size of the salt particles can give a faster perception of salty taste, meaning that less salt is needed. This works best where salt is added dry, such as in snacks, but can work even when dissolved, since the distribution of salt is increased when particle size is reduced. Hollow salt particles, such as those in SODA-LO’s salt microspheres, also offer the potential for successful salt reduction.
- Reposition the salt. This can be achieved in different ways. For example, research has shown that layering salt in bread with different salt levels can provide sufficient taste and functionality to help reduce sodium whist maintaining acceptable properties such as aeration and shelf life. An alternative technique with emulsions is to prepare double emulsions of water in oil in water, where the salt is positioned entirely in the external water phase, thus making the level higher in this phase but overall lower in total.
So, whilst the salt reduction targets set by PHE are definitely a challenge to the industry, there are options open to manufacturers. Scientific approaches to reformulation will equip product developers with the necessary understanding and knowledge to successfully reformulate products whilst maintaining shelf life and the sensory characteristics consumers love.