Salt: A pinch in time saves nine

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September 06, 2017

by Steve Green



MMR Founding Director Steve Green talks through the science behind salt in food - and why reducing it isn't as simple as it sounds


MMR has seen interest in reduction of salt in food products increase significantly over the past year.This reflects increasing media attention on the way foods are manufactured, growing consumer awareness of the impact of salt on health and moves towards more regulatory control of salt levels in processed foods.The World Health Organization (WHO) issued updated advice on salt intake in June 2016 which makes clear recommendations for how governments, manufacturers and individuals should act to manage the amount of salt consumed in the diet.The actions they recommend have far reaching implications. For instance, one of the key broad strategies is that government policies should include:


...appropriate fiscal policies and regulation to ensure food manufacturers and retailers produce healthier foods or make healthy products available and affordable...

WHO Salt Reduction Fact Sheet June 2016


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Governments and regulatory bodies are introducing policies aimed at reducing salt intake.The US Food and Drug Administration has issued draft guidelines with voluntary sodium reduction goals for the industry, with 2 year and 10 year implementation goals.The shorter time frame reflects the fact that it typically takes around two years for a food manufacturer to develop and launch a reformulated product. The long term goals reflect the ambitious and challenging nature of the reduction targets, for example:

Product 2 year goal 10 year goal
Cookies 17% 39%
Ready to eat cereals 16% 45%
Flavored potato & vegetable snacks 16% 44%
White bread 16% 43%
Hummus 10% 31%
Butter 11% 30%
Cheddar cheese 6% 16%

The size of reduction recommended is related to the typical salt content of the product, but also to the volume of product consumed within the average diet. More popular, more frequently consumed products are expected to achieve greater salt reduction, because they have a bigger cumulative impact on the amount of sodium consumed in a population than products that are only consumed infrequently. This explains why cookies are expected to make a larger salt reduction than hummus, despite cookies having 30% lower salt content than hummus.

It is also interesting to see a relatively low salt reduction target for products such as butter and cheese, which are commonly considered to be salty products. This is because salt does more than just change the taste of food. Salt can act as a natural preservative and plays an important role in food safety. For example, in cheese production salt is used to aid coagulation by drawing the liquid whey out of the solid cheese curds. This reduces the amount of water in the cheese available for bacteria to grow, reducing the risk of both food poisoning and spoilage. It also directly impacts the texture, with softer cheeses developed using a lower salt concentration in contrast to harder higher salt cheeses.

Most people are very familiar with the way that salt changes the taste of food, although describing exactly how the taste changes is very difficult, because “saltiness” is only one part of the experience. Salt enhances flavors and rounds out and balances the sensory characteristics of products. It takes skill to judge the right amount of salt needed to deliver a great taste experience.

In most markets where packaged, processed food products are well established and readily available, consumers have become used to the taste of salted products. Over many years, people have become conditioned to like and expect products to deliver a strong savory, salty taste. Most consumers find it quite easy to detect if salt has been reduced in a product. Many will find it hard to say exactly what has changed, but the majority will notice a difference.

Large reductions in salt can have a dramatic impact on the taste and texture of products and can stop consumers enjoying the product so much that they no longer want to eat it. Smaller noticeable reductions often lead consumers to describe the product as tasting bland, flat, stale or boring. Given the choice, consumers may well switch to a different brand that delivers a better flavor, rather than compromise on enjoyment. Or, given another choice, consumers may decide to trade the health benefit of reduced salt against a small reduction in taste. Some will and some won’t. The issue confronting food manufacturers, is that consumers do have a choice and they have got used to - and like, salty products.

The degree to which a certain level of salt reduction impacts on the taste of a product varies across different types of foods. Generally, products with simpler, or milder flavor profiles are more sensitive to changes in salt level. But it is difficult to generalize effects, because the impact of salt is both complex and subtle. Our experience of working on salt reduction projects is that once the level of reduction rises above 10% consumers generally notice differences. Reductions in the 20% to 30% range usually need significant programs of reformulation work to deliver a product that has a taste profile that is acceptable to consumers. Salt reduction targets of 40% upwards are very challenging and are very difficult to achieve in a single step.

It is easier in products where other characteristics can be re-balanced to offset the impact of salt – although that can still be a difficult task, because emphasizing other flavor characteristics is likely to change the product experience and that may not fit with what consumers expect. This is particularly an issue for well established brands and for products that have a very distinctive sensory signature. Consumers do notice changes and social media gives them a powerful way of voicing their opinions. Caveat venditor - let the seller beware!


It takes skill to judge the right amount of salt needed to deliver a great taste experience.


MMR’s experience is that a well designed product reformulation program can deliver successful salt reductions. The most effective approach we have found combines trained descriptive analysis panels with structured consumer testing. This gives the product development team the direction needed to build incisive prototypes and identify the optimum low salt formulation.

Our starting point is usually to work with clients to produce a range of product formulations prepared with different levels of salt – most with lower levels of salt, but some with higher levels too.These products can be made in small batches and use the current marketplace formulation as the base recipe. We then ask a trained sensory panel to try the products and describe the nature and intensity of the sensory characteristics present in each product. The panel is trained to describe and rate the attributes of foods accurately and consistently. The result is an “objective” fingerprint of the way each product looks, smells, tastes and feels. We encourage the product developers and our consumer research experts to collaborate with the panel through this process, especially when reviewing the results. The outcome is a very clear understanding of exactly how changing salt level changes the sensory characteristics of the product.

If the impact is relatively subtle, we can select prototypes with reduced levels of salt to put into consumer research to understand if the changes matter to consumers. If salt reduction seems to have a larger impact on the product, we review the nature of the changes and work with the product development team to identify ways the product could be reformulated, or processed differently to off-set those changes. For instance, if the Oregano character has reduced, can we increase the amount of herb used to give more flavor. This identifies and prioritizes reformulation routes, giving the team a clear product development brief. Once new prototypes have been made, they can be assessed by the panel to see which changes re-balance the flavor profile of the product best.

The next stage is to ask consumers to assess the salt reduced products. Occasionally we will run a head-to-head test between the current product and the salt reduced product. If the new product performs well, this validates the move to the lower sodium formulation. But, our experience is that this approach gives limited and rather blunt feedback. If the reduced salt product does not perform as well as the current product, there is no way of determining what level of salt reduction would have worked.

We find it is better to adopt an Experimental Design (sometimes called Design of Experiments) approach, where a series of prototypes are tested that demonstrate a systematic change in key formulation factors. At its simplest, this could involve only changing one factor, salt level, in the prototypes.Typically, we would use about 5 prototypes with different levels of salt. All prototypes would be tested by consumers. This allows us to determine precisely the relationship between salt level and consumer liking (or other consumer perceptions of the product). The advantage of this approach is that the results show a direct cause and effect link between the formulation change and consumer opinion. This information can be used to decide the level of salt reduction that could be made without overall liking falling significantly.

Where this Experimental design approach becomes very powerful is when we have more than one factor to consider. For example, in the earlier example Oregano was identified as a way of re-balancing product characteristics. This means we have two factors to explore: salt level and Oregano level. The experimental design approach will enable us to determine the way that salt and Oregano interact to drive consumer liking. Once again the optimum levels of salt and Oregano can be calculated. This is important, because not only does this allow us to define a formulation that performs well with consumers, but it also allows us to use the minimum amount of Oregano required to make the product ideal for consumers. Herbs are an expensive ingredient, so it is very important to not add more than is needed.

Salt reduction is a challenge. In our experience, careful, systematic product development is the best way of achieving success, supported by sensory panels and consumer research. The whole process takes thought, skill and time to execute effectively. If salt reduction is on your agenda, my advice is make a systematic plan and implement it sooner rather than later.

Hyperlinks:

http://www.who.int/mediacentre/factsheets/fs393/en/

https://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/ucm494732.htm

Steve Green is a Founding Director at MMR Research Worldwide.